.NET Tips & Tricks Community

.net tip

Wed, 17 Feb 2010 09:10:16 GMT

.net tip

submitted by tiper

Using Progressbar in a Class

Mon, 23 Nov 2009 15:33:55 GMT

You sometimes need to send a progress report to the user on the status of a particular function. Ex. when inserting records etc.

// FROM YOUR FORM

private void button1_Click(object sender, EventArgs e)

{

yourclass.updatedb({"One","Two","Three"},this.ProgressBar1);

}

// INSIDE YOUR CLASS

public string updatedb(string[] values,System.Windows.Forms.Progressbar pb)

{

pb.Maximum = values.Length();

foreach(string v in values)

{

_insertdb(v); // CALL THE UPATE DB METHOD

pb.Value ++; // UPDATE PROGRESSBAR

}

submitted by Paul

Using Progressbar in a Class

Mon, 23 Nov 2009 15:33:13 GMT

You sometimes need to send a progress report to the user on the status of a particular function. Ex. when inserting records etc.

// FROM YOUR FORM

private void button1_Click(object sender, EventArgs e)

{

yourclass.updatedb({"One","Two","Three"},this.ProgressBar1);

}

// INSIDE YOUR CLASS

public string updatedb(string[] values,System.Windows.Forms.Progressbar pb)

{

pb.Maximum = values.Length();

foreach(string v in values)

{

_insertdb(v); // CALL THE UPATE DB METHOD

pb.Value ++; // UPDATE PROGRESSBAR

}

submitted by Paul

Using Progressbar in a Class

Mon, 23 Nov 2009 15:32:08 GMT

You sometimes need to send a progress report to the user on the status of a particular function. Ex. when inserting records etc.

// FROM YOUR FORM

private void button1_Click(object sender, EventArgs e)

{

yourclass.updatedb({"One","Two","Three"},this.ProgressBar1)

}

// INSIDE YOUR CLASS

public string updatedb(string[] values,System.Windows.Forms.Progressbar pb)

{

pb.Maximum = values.Length();

foreach(string v in values)

{

_insertdb(v); // CALL THE UPATE DB METHOD

pb.Value ++;

}

submitted by Paul

Using Progressbar in a Class

Mon, 23 Nov 2009 15:31:02 GMT

You sometimes need to send a progress report to the user on the status of a particular function. Ex. when inserting records etc.

// FROM YOUR FORM

private void button1_Click(object sender, EventArgs e)

{

yourclass.updatedb({"One","Two","Three"},this.ProgressBar1)

}

// INSIDE YOUR CLASS

public string updatedb(string[] values,System.Windows.Forms.Progressbar pb)

{

pb.Maximum = values.Length();

foreach(string v in values)

{

_insertdb(v); // CALL THE UPATE DB METHOD

pb.Value ++;

}

submitted by Paul

Using Progressbar in a Class

Mon, 23 Nov 2009 15:30:46 GMT

You sometimes need to send a progress report to the user on the status of a particular function. Ex. when inserting records etc.

// FROM YOUR FORM

private void button1_Click(object sender, EventArgs e)

{

yourclass.updatedb({"One","Two","Three"},this.ProgressBar1)

}

// INSIDE YOUR CLASS

public string updatedb(string[] values,System.Windows.Forms.Progressbar pb)

{

pb.Maximum = values.Length();

foreach(string v in values)

{

_insertdb(v); // CALL THE UPATE DB METHOD

pb.Value ++;

}

submitted by Paul

Use delegates to utilize a callback pattern

Thu, 01 Jan 2009 12:26:47 GMT

Essentially delegates are function pointers (which is a concept used in languages like C/C++). They are also a class in the .net programming framework (System.Delegate). It is an abstract class and its sealed; meaning you cannot inherit it. Delegates are object oriented, type-safe and secure.

Any method that matches the delegate's signature, which consists of the return type and parameters, can be assigned to the delegate. This makes is possible to programmatically change method calls, and also plug new code into existing classes. As long as you know the delegate's signature, you can assign your own delegated method.

Asynchronous patterns of code execution mainly employ the callback pattern. The callback function will execute once the asynchronous task completes. Developers mainly utilize this idea so that the end-users get the benefit of executing a followup routine (post asynchronous operation), but the developer need not know what that routine is or what it does. However the developer has to ensure that that routine (which is a method) has a signature that the end users specify.

Take the example of the FileStream class in the System.IO namespace. It is mainly used for I/O. It has methods like BeginRead() and BeginWrite(); they are asynchronous versions of Read() and Write() respectively. They execute on a different thread.

If you examine the prototype of the first method you would find the third argument (AsyncCallback userCallback) is actually a delegate. And, it expects a method whose return type is void and takes one argument of type IAsyncResult.

public override System.IAsyncResult BeginRead(byte[ ] array, int offset, int numBytes, System.AsyncCallback userCallback, object stateObject)

The declaration for AsyncCallback is:

public delegate void AsyncCallback(System.IAsyncResult ar)

The BeginRead() method returns a value of type IAsyncResult. If you want to wait for an asynchronous read-operation to end, you have to call EndRead() and pass the corresponding IAsyncResult value.

On a general note those classes which do some operation asynchronously have their corresponding Begin and End methods. Keep exploring to find out.

Happy programming. (and a happy new 2009). ;)

submitted by deostroll

Format the current document in Visual Studio

Wed, 26 Nov 2008 17:27:53 GMT

Press ctrl +E, D, It will apply the format(like indent, spacing etc) to whole current document.

submitted by Yaseen

WPF Equivalent for ListView.GetItemAt(e.X,e.Y)

Tue, 16 Sep 2008 16:57:51 GMT

FrameworkElement framework = e.OriginalSource as FrameworkElement;

ListViewItem lvi = Lstview.ItemContainerGenerator.ContainerFromItem(fe.DataContext) as ListViewItem;

submitted by Renuka

Generating artificial phone numbers (in North America)

Thu, 28 Aug 2008 23:22:53 GMT

Having worked for a company that developed phone fraud detection software in a previous life, I was familiar with the North American Numbering Plan described in Wikipedia. Several times I’ve had a need to create artificial phone numbers.

Below is an algorithm that will handle most if not all of these numbers.

private string GetRandomPhone()
{
    // Generate a NANP compliant phone number (look in wikipedia under North American Numbering Plan)
    var rnd = new Random();
 
    // A number consists of 3 parts: NPA Nxx Station
    // NPA (Numbering Plan Area code) = [2-9][0-8][0-9] 
    // Exclude common toll and toll-free numbers
    int npa = 0;
    while (npa == 0 || npa == 800 || npa == 877 || npa == 888 || npa == 900)
    {
        npa = rnd.Next(2, 9) * 100 + rnd.Next(0, 8) * 10 + rnd.Next(9);
    }
 
    // NXX (Central Office or Exchange code) = [2-9][0-9][0-9]
    // Exception the second digits may not be 11
    int nxx = 0;
    while (nxx == 0 || nxx % 100 == 11)
    {
        nxx = rnd.Next(2, 9)*100 + rnd.Next(99);
    }
 
    // Station code = [0-9][0-9][0-9][0-9]
    // When 555 is the NXX the number 100-199 are reserved or fictional numbers)
    int station = 0;
    while (station == 0 || (nxx == 555 && station > 99 && station < 200))
    {
        station = rnd.Next(9999);
    }
 
    const string format = "({0:000}) {1:000}-{2:0000}";
    return string.Format(format, npa, nxx, station);
}

submitted by jtheisen

LINQ to XML method chaining

Wed, 27 Aug 2008 00:24:46 GMT

First, I have to say that I really love using LINQ to SQL and LINQ to Objects. I wasn’t able to say the same thing about LINQ to XML until recently.

Here’s an XML document that I’ll use for this example:

<Zoo>
  <Animals>
    <Animal species="monkey">George</Animal>
    <Animal species="monkey">Zanzi</Animal>
    <Animal species="panda">Long-Long</Animal>
  </Animals>
</Zoo>

I’m very familiar with XPath expressions and if I wanted to find all of the panda’s in the Zoo I could write an expression like:

/Zoo/Animals/Animal[@species=’panda’]

So that works great and it would return to me the element containing ‘Long-Long’. Now for the LINQ to XML equivalant without using the XPath Extensions Method.

var panda = doc.Element("Zoo").Element("Animals").Descendants("Animal")
    .Where(e => e.Attribute("species").Value == "panda");

The problem is that all of the italic, underlined and in red text (i.e. the .Element() and .Attribute()) methods can return null. So, I went from a clear and consise XPath expression to a less readable LINQ call that I should be checking for null for each of the Element and Attribute calls. Hmmm, not good.

Fortunately, .NET 3.5 introduces Extension Methods that allow us to extend existing classes with new Methods. Here’s the class that I came up with:

public static class XmlExtensions
{
    public static XElement SafeElement(this XContainer container, string name)
    {
        return container.Element(name) ?? new XElement(name);
    }
 
    public static XAttribute SafeAttribute(this XElement element, string name)
    {
        return element.Attribute(name) ?? new XAttribute(name, "");
    }
}

For an introduction on Extension Methods, read this blog entry from ScottGu here. Note that there are three indicators that this is an extension method:

The class has been declared static.
Each of the extension methods is also static.
There is a “this” keyword before the first parameter argument.

The ‘SafeElement’ method is extending the XContainer class and the ‘SafeAttribute’ method is extending the XElement class.

We these are used in our example we get:

var panda = 
doc.SafeElement("Zoo").SafeElement("Animals").Descendants("Animal")
    .Where(e => e.SafeAttribute("species").Value == "panda");

If you are using Resharper you will see the squiggles disappear from the expression now. So, how and why does this work and allow us to use expression chaining? Since we are guaranteed to get an either an XElement or XAttribute back from the respective calls, we won’t blow up with a NullReferenceException. That’s good. In addition, since we return an empty Element or Attribute, our other chained calls will fail cleanly, thus the Lamba Expression will not match any items if we had loaded a different XML document.

submitted by jtheisen

Launching solution file from the command line

Wed, 20 Aug 2008 08:33:33 GMT

Before Resharper came along and clutter my directories with files, I used tab-completion to launch my solution files from the command line using:

START MyApplication.sln

But, with two other resharper files now preceeding the solution file I needed another way to launch the solutution file. Here’s the script that I came up with:

@ECHO OFF

FOR %%n IN (*.sln) DO START %%n

If you have more than one solution file in the same directory, this script is not for you, but that is not a likely scenario. I saved this file as sln.bat and put in the \windows\system32 directory, although any directory in your PATH will do.

submitted by John Theisen

Making your ASP.NET Ajax Webservice calls faster

Tue, 12 Aug 2008 18:56:24 GMT

An article talking about making ASP.NET Ajax Webservice calls faster by using a technique to divide the Ajax calls into several sub domains. The article includes a JavaScript class that acts like a manager for Ajax Webservice calls giving them several benefits. Its usage is transparent and you do not need to change your existing code. Any developer who uses ASP.NET Ajax Webservice calls should not miss this article.

submitted by Ralph Varjabedian

How to register a .NET Assembly without using gacutil

Wed, 09 Jul 2008 09:24:32 GMT

If the target machine does not have gacutil.exe (for example if SDK is not installed) doing a .NET script to do the same is very easy.

- Add reference to System.EnterpriseServices assembly and

using System.EnterpriseServices.Internal; 
... 
Publish p = new Publish(); 
// for GAC Installation 
p.GacInstall(file); // for gac installation 
... 
p.GacRemove(file); // for gac removing 
... 
p.RegisterAssembly(file); // for registering assembly for interop 
... 
p.UnRegisterAssembly(file); // to unregister assembly

Carefull thow on Vista you should probably try running the program as an Administrator

submitted by sharpoverride

Why DotNetTipOfTheDay can lick my balls (a memo):

Thu, 03 Jul 2008 18:13:05 GMT

I think it is safe to say this website sucks ass.

Practically two months without an update when people have been submitting things for you to post.

I am pretty lazy when it comes to a lot of things, and up until today have kept your shitty RSS feed in my reader in hopes that you would actully update the site some day.

But you suck and I hope your website bombs.

Burn in hell.

-thiswebsitesuck

submitted by thiswebsitesucks

Fill datset without open connection

Wed, 11 Jun 2008 09:09:21 GMT

There is no need

Connection.Open

Before calling Method

Adapter.Fill(Dataset)

public override DataSet getSMCommentedSubmission(string prodID, string salesID)
        {
            using (SqlConnection cn = new SqlConnection(this.ConnectionString))
            {

                SqlCommand cmd = new SqlCommand("sp_WB_Submission", cn);
                SqlDataAdapter adp = new SqlDataAdapter(cmd);
                DataSet dset = new DataSet();
                cmd.CommandType = CommandType.StoredProcedure;

                cmd.Parameters.Add("@SqType", SqlDbType.Int).Value = 48;
                cmd.Parameters.Add("@PubPlanID", SqlDbType.Int).Value = null;
                cmd.Parameters.Add("@TypeID", SqlDbType.Int).Value = null;
                cmd.Parameters.Add("@Title", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@CommentID", SqlDbType.Int).Value = null;
                cmd.Parameters.Add("@ThemeText", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@StorySynopsys", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@Status", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@Comments", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@TimeStamp", SqlDbType.SmallDateTime).Value = null;
                cmd.Parameters.Add("@PublisherID", SqlDbType.Int).Value = null;
                cmd.Parameters.Add("@PermissionType", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@Checked", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@SMStatus", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@PMStatus", SqlDbType.VarChar).Value = null;
                cmd.Parameters.Add("@ProductionManagerID", SqlDbType.VarChar).Value = prodID;
                cmd.Parameters.Add("@SalesManagerID", SqlDbType.VarChar).Value = salesID;
                cmd.Parameters.Add("@StoryID", SqlDbType.Int).Value = null;
                cmd.Parameters.Add("@Review", SqlDbType.Int).Value = null;


                adp.Fill(dset);

                return dset;

            }
        }

submitted by Ajay

Never lock on a value type

Wed, 04 Jun 2008 23:01:26 GMT

When locking on a value type it gets boxed, meaning a new object instance is allocated and passed to the lock statement. Thus every time you lock on a value type, you're locking on a new object. Here is an example of bad code:

    private bool flag = false;
 
    public void Method1()
    {
        lock(flag)
        {
            ...
        }
    }

submitted by kostya.ly

need to use either “using” or explicitly close the connection if we use the datareader

Thu, 15 May 2008 16:49:14 GMT

We need to use either “using” or explicitly close the connection if we use the datareader.

Otherwise, it will lead to Connection Pool error. See the underlined text below:

However, there are other cases where it is unclear when to close the connection. An example is the ExecuteReader method. This method returns an object that implements the IDataReader interface. The Database base class has a default implementation that returns a DbDataReader object. DbDataReader objects are designed to read specific portions of the data as needed, which requires an open connection. In other words, it is unknown when the application no longer needs the DbDataReader. If the Data Access Application Block methods close the connection before returning the DbDataReader, the DbDataReader becomes useless to the client code. Instead, the DbDataReader methods indicate to the underlying ADO.NET call to automatically close the connection when the DbDataReader is finished. In this situation, it is considered a best practice for the application to ensure that the DbDataReader is closed in a timely fashion, either by explicitly closing the reader with the DbDataReader.close method or by forcing the disposal of the DbDataReader, which results in the Close method being called.

The following code demonstrates a call to the ExecuteReader method. The using statement (Using in Visual Basic) ensures that the DbDataReader object is disposed, which closes the DbDataReader object.

[C#]

Database db = DatabaseFactory.CreateDatabase();

DbCommand dbCommand = db.GetSqlStringCommand("Select Name, Address From Customers");

using (IDataReader dataReader = db.ExecuteReader(dbCommand))

{

// Process results

}

submitted by saisuchir

BrowsableAttribute

Tue, 13 May 2008 15:43:13 GMT

when u are creating a control, and u decides that a property or a event should not be displayed in property window.

System.ComponentModel.BrowsableAttribute is there for you, to do the above.

Eg:

private string text;

[Browsable(false)]        // True is default
public string Text
      {
         get
         {
            return text;
         }
         set
         {
            text = value;
         }
}

submitted by dhanaid

Get rid of unused usings

Mon, 12 May 2008 20:05:08 GMT

In a Visual Studio 2008 source window, right-click and select Organize Usings | Remove Unused Usings. Visual Studio 2005 users may use ReSharper for this.

P.S. interesting, does this optimization gives you any benefits other than cleaner code?

submitted by kostya.ly

Capitalization of ID and OK abbreviations used in identifiers

Wed, 07 May 2008 01:59:56 GMT

I was wondering how to capitalize properties which have either ID or OK abbreviation in its name. For example, is it TipID or TipId? I have found the answer in Design Guidelines for Developing Class Libraries:

In Pascal-cased identifiers (all identifiers except parameter names) they should appear as Id, and Ok. If used as the first word in a camel-cased identifier, they should appear as id and ok, respectively.

P.S. And of course .NET Framework doesn't fulfil this rule :) For example, Control.ClientID property.

submitted by kostya.ly

How to loop through all rows of the DataTable?

Wed, 30 Apr 2008 19:35:54 GMT

foreach (DataRow row in dTable.Rows)
{
yourvariable = row["ColumnName"].ToString();
}
 
//OR 
for (int j = 0; j< dTable.Rows.Count; j++)
{
yourvariable = dTable.Rows[j]["ColumnName"].ToString()l
}
 

submitted by Raja

To avoid line by line debug using F11

Tue, 29 Apr 2008 13:58:47 GMT

Use DebuggerStepThroughAttribute

[System.Diagnostics.DebuggerStepThrough()]

public void sample()

{

// ....

}

submitted by dhanaid

Bind a TreeView to a DataSet or an ObjectDataSource with one line of code

Wed, 23 Apr 2008 15:19:16 GMT

This post has a class that allows you to bind your TreeView to a dataSet very easily.

http://www.varjabedian.net/archive/2008/04/22/binding-asp.net-treeview-to-a-dataset-or-an-objectdatasource.aspx

submitted by Ralph Varjabedian

Usuful VS Shortcuts

Thu, 17 Apr 2008 20:23:07 GMT

F7 Jump to Code Behind

Ctrl+F6 Navigate between various opened panes

Ctrl+Shift+V Cycle through the clipboard ring

CTRL+K+K Create or delete Bookmark

Ctrl+K+D Auto-format whole page

Ctrl+K+F Auto-format selection

Ctrl+U Convert to lower case

Ctrl+Shift+U Convert to upper case

Ctrl+M+M Fold/Unfold the current code block

Ctrl+M+L Unfold all

Block Selection Press and hold Alt and then select the area you want with your mouse.

submitted by eswarp

Useful VS Shortcuts

Thu, 17 Apr 2008 20:20:45 GMT

F7 Jump to Code Behind

Ctrl+F6 Navigate between various opened panes

Ctrl+Shift+V Cycle through the clipboard ring

CTRL+K+K Create or delete Bookmark

Ctrl+K+D Auto-format whole page

Ctrl+K+F Auto-format selection

Ctrl+U Convert to lower case

Ctrl+Shift+U Convert to upper case

Ctrl+M+M Fold/Unfold the current code block

Ctrl+M+L Unfold all

Block Selection Press and hold Alt and then select the area you want with your mouse.

submitted by Eswar

Summary Tag in visual studio 2008 IDE

Sun, 06 Apr 2008 01:00:59 GMT

want to XML comment ur code ??

just type /// (three slashes) on top of any class or method and the vs 2008 ide will automaticaly generate summary tag which will also give you out of the box functionality of intellisense when you use the particualar method with summary tag here is an example

http://msdn.microsoft.com/vstudio/tour/vs2005_guided_tour/VS2005pro/Library/XMLComments.2.jpg

submitted by l33tc0der

Can you store multiple data types in System.Array?

Sat, 05 Apr 2008 21:03:45 GMT

If you search the answer for this questions, you will find most websites just copy the answer "No", but actualy the correct answer should be Yes, because the code below proves it: C# System.Object[] test_array = new System.Object[6]; test_array[0]="123go!"; test_array[1]=2007.7; test_array[2]=true;

submitted by Kailash Dhondiyal

Parse vs TryParse in conversion from string

Thu, 03 Apr 2008 06:51:25 GMT

Consider using TryParse and TryParseExact when converting from string to int, long, DateTime, etc. TryParse functions return true if conversion was successful and resulted value returned in out parameter. They do not throw an exception, which is a lot faster than Parse functions.

string ageStr = "35";
string invalidAgeStr = "TestAge 35";
int age = 0;
 
if (int.TryParse(ageStr, out age))
{
    MessageBox.Show("Age: " + age);
}
if (!int.TryParse(invalidAgeStr, out age))
{
    MessageBox.Show("Invalid Age: " + invalidAgeStr);
}

submitted by Vlad

Opening file in Windows Explorer - Faster

Mon, 24 Mar 2008 18:57:32 GMT

Using this tip to add the Windows Explorer to the tools list http://dotnettipoftheday.org/tips/explorer-in-tools-menu.aspx. You can assign a keyboard shortcut to it.

Open the tools menu to identify which external command the Windows Explorer is set as, then select Tools -> Customize and choose Keyboard. Enter "External Command" in the search box. Select the command number based on what was displayed in the tools menu and assign a keyboard shortcut.

submitted by MADCookie

Use "it's" and "its" Correctly

Mon, 24 Mar 2008 18:52:11 GMT

"it's" is the contraction of "it is" "its" is possessive If you can re-word your "its" as "it is" then you're not using it correctly.

submitted by Rich Wilson

Get UserId from User Name in ASP.NET

Mon, 17 Mar 2008 09:07:13 GMT

MembershipUser myUser = Membership.GetUser();
string userID = myUser.ProviderUserKey.ToString()

MembershipUser myUser = Membership.GetUser(My.User.Name);
string userID = myUser.ProviderUserKey.ToString()

Links

Membership.GetUser Method
Gets the information for a membership user from the data source.

submitted by Jose A. Fernandez

Reading Eventlog of a Remote Machine

Tue, 04 Mar 2008 14:41:49 GMT

Reading Eventlog of a Remote Machine

Include System.Diagnostics
Getting the eventlogs of a remote machine say MachineName

EventLog[] eLogs = EventLog.GetEventLogs(MachineName); //Can also use IPAddress of the machine as EventLog.GetEventLogs(IPAddress)

The name of the ith eventlog can be obtained from the eLogs[i].LogDisplayName property of the eventlog object.
Suppose we want to get the object for the eventlog named MyEventLog in machine MachineName. We can get that as:

EventLog elog = new EventLog(MyEventLog , MachineName);
To access the different entries in the eventlog we can use the array eLog.Entries
For ith entry, the different properties we can get are:

elog.Entries[i].EntryType

elog.Entries[i].TimeGenerated

elog.Entries[i].Source

elog.Entries[i].Category

elog.Entries[i].InstanceId

elog.Entries[i].UserName

elog.Entries[i].Message

elog.Entries[i].MachineName

submitted by Saurav Kumar Jaiswal

Add Windows Explorer to your Visual Studio tools menu

Sun, 24 Feb 2008 05:57:40 GMT

I often need to open Windows Explorer and browse to the current file, folder, or project that I am working on in Visual Studio. This tip allows you to achieve this by clicking "Windows Explorer" in the Tools menu, and is one of the most simple-yet-useful tips I know of.

To set it up, click "Tools", then "External Tools...", then click "Add". Now enter the following data:
Title: Windows Explorer
Command: explorer.exe
Arguments: /select,"$(ItemPath)"

Leave "Initial directoy" blank, and click "OK". Now when you click "Tools", "Windows Explorer", Windows Explorer will open with the current file you are editing selected.

submitted by Daniel Flower

Toggle intelisense transperancy on the fly

Mon, 18 Feb 2008 12:32:55 GMT

When typing in VS2008 and intellisense blocks the view of the lines of code underneath. You can hold down the Ctrl key to toggle the opacity of the intelisense box so that you can see the code under it.

submitted by Kalle Hoppe

WPF Textbox memory leak

Sat, 16 Feb 2008 12:27:39 GMT

While running around in the WPF forums, I found this very interesting post (http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2823829&SiteID=1)… It seems that the WPF TextBox can be dangerous :) - if you do not use it carefully :)

Basically the TextBox by default stores all text changes in an Undo Stack… This implies that every time that you change the Text of the TextBox more memory is consumed by the TextBox.

In order to fix this you have to set the UndoLimit property to 0. This would disable the Undo feature for the TextBox and thus NO MORE MEMORY CONSUMPTION …

Have a nice day

submitted by Marlon Grech

Format your code

Tue, 12 Feb 2008 00:51:30 GMT

You can format your code by selecting the code you want to format and pressing ctl + K +F. This shortcut can also be applied to html.

submitted by Bilal Shouman

Adding required field validator to DropDownList

Tue, 12 Feb 2008 00:32:17 GMT

You can set a required field validator to a drop down list as follows

<asp:DropDownList ID="ddlItems" runat="server">
    <asp:ListItem Text="<--Select Item-->" Value=""></asp:ListItem>
    <asp:ListItem Text="Item 1" Value="1"></asp:ListItem>
    <asp:ListItem Text="Item 2" Value="2"></asp:ListItem>
    <asp:ListItem Text="Item 3" Value="3"></asp:ListItem>
</asp:DropDownList>

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" ControlToValidate="ddlItems" runat="server" ErrorMessage="Please select an item" Text="Pelase select an Item"></asp:RequiredFieldValidator>

submitted by Bilal Shouman

Show/Hide ASP.NET Non-visual controls in the designer

Mon, 11 Feb 2008 13:19:51 GMT

Sometimes it is useful to show/hide ASP.NET Non-visual controls in the designer. For this:

Swith to Design view
From the View menu, click Visual Aids and select/unselect ASP.NET Non-visual Control option or just press CTRL+SHIFT+N.

Enjoy! :)

submitted by Sergey P.

Chaining the C# ?? Operator

Tue, 29 Jan 2008 18:33:18 GMT

In C# you can shortcut this special null comparison case with the new ??:

string result = value1 ?? value2;

which is a little easier to write. This is probably not news to you, but what's really useful is that you can chain these operators together so you can do a whole bunch of null comparisons in a single stroke. For example, I frequently look for a few different querystring variables in a page:

string partner = Request.QueryString["GoogleId"] ??
    Request.QueryString["PartnerId"] ??
    Request.QueryString["UserKey"] ??
    string.Empty;

which still yields a valid result for the first non-null querystring or if nothing is found returning "".

More found here: http://www.west-wind.com/weblog/posts/236298.aspx

submitted by Jacob Cook

How to enable Text Editor Guide Lines in Visual Studio

Fri, 25 Jan 2008 19:29:05 GMT

A not well known feature of Visual Studio (2002/3/5/8) is the ability to add a Guide Line to the text editor, which would show a visible line indicating a specific column. This feature of Visual Studio lets you display a vertical line at the column of your choosing to help visually see when a line is getting too long. This helps you to define a maximum acceptable column, where code should have a line break to look clear and sharp on all monitor resolutions.

Please beware that registry manipulation is needed, so DO IT AT YOUR OWN RISK!

Open a command prompt and run the following command:

REG ADD "HKCU\Software\Microsoft\VisualStudio\[Version]\Text Editor" /v Guides /d "RGB([R],[G],[B]) [COL1], [COL2]"

You should replace:

[Version]- the Visual Studio Version (Please note: 2005 = 8.0 ; 2008 = 9.0)
[R] = RGB Red value (0-255) of the line
[G] = RGB Green value (0-255) of the line
[B] = RGB Blue value (0-255) of the line
[COL1] [COL2] = The column number where to show the line. You can have at most 13 lines.

As an example, you can run the following command:

REG ADD "HKCU\Software\Microsoft\VisualStudio\8.0\Text Editor" /v Guides /d "RGB(128,0,0) 80, 120

Which would add two columns (column 80 and column 120).

Voilá! Now you know when lines are to large...

submitted by Hugo Batista

Disable Theming and StyleSheet theme for one specific page in Asp.Net

Fri, 25 Jan 2008 12:05:38 GMT

The theming features of asp.net works by just putting one line inside the Web.Config file, this to enable a theme and change the look of the complete website. But what to do when you want to disable everything for one specific page?

There are 2 page directives, Theme and StyleSheetTheme that help setting the themes.

<%@ Page Language=”C#” Theme=”OrangeTheme” StyleSheetTheme=”GreenTheme” %>

But to disable them the documentation will only provide following answer.

<%@ Page Language=”C#” EnableTheming=”false” %>

But the EnableTheming will only effect the choosen theme and will not effect the StyleSheet theme!!!
So to disable both these features just use following code:

<%@ Page Language=”C#” Theme="" StyleSheetTheme="" %>

Took me a while to figure this one out :)

submitted by Glenn Versweyveld

Clear "Recent Projects" list from Start page in Visual Studio .NET

Thu, 24 Jan 2008 14:35:08 GMT

Here is a nice tips to clear the Recent project list or File list from "Start page" of Visual Studio.Net

Go to Start -> Run -> RegEdit

and navigate to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\\ProjectMRUList delete unnecessary list.

Similarly for FileMRuList.

Make sure not disturb other key from the registry.

submitted by Kaushal

Automatic Properties

Thu, 17 Jan 2008 13:06:11 GMT

In the latest release of Orcas, one of the new features provided is "Automatic Properties" which allows developers to use a shorthand like the following:

public class Person {
 
    public string FirstName {
        get; set;
    }
 
    public string LastName {
        get; set;
    }
 
    public int Age {
        get; set;
    }
}

and the compiler knows to interpret this as

public class Person {
 
    private string _firstName;
    private string _lastName;
    private int _age;
 
    public string FirstName {
        get {
            return _firstName;
        }
        set {
            _firstName = value;
        }
    }
 
    public string LastName {
        get {
            return _lastName;
        }
        set {
            _lastName = value;
        }
    }
 
    public int Age {
        get {
            return _age;
        }
        set {
            _age = value;
        }
    }
}

submitted by Joe

prop Code Snippet in VS 2005

Thu, 17 Jan 2008 13:04:42 GMT

You can use the "prop" code snippet in VS 2005 to easily create properties inside a class. So, if you type prop inside a class in VS 2005, you will get something like:

private int myVar;
 
public int myProperty
{
    get {return myVar;}
    set {myVar = Value;}
}

As you can see, it defaults to an int, but simply type string on line 1 and it will change both "int" fields to strings. Likewise, changing myVar will not only change it on the first line, but also in both locations within the get/set accessors (line 5 and 6).

submitted by Joe

Easily Creating Properties in VS 2005 (C#)

Tue, 15 Jan 2008 14:05:48 GMT

You can use the "prop" attribute to easily create properties in vs 2005 (C#).

submitted by Joe

Automatic Source Code Formatting

Tue, 15 Jan 2008 13:47:21 GMT

You can use ctrl k + d to automatically format your html of server code in VS 2005.

submitted by Joe

Launch DTS from Asp.net page

Tue, 15 Jan 2008 12:51:58 GMT

Introduction

Data Trasformation Services (DTS) is a tool and set of programmable objects that lets you extract, trasform and consolidate data from various source into various destinations.

How to

Launch a DTS from Asp.net page is much useful, when you must import some data from disparate sources. First, add reference Microsoft.SqlServer.ManagedDTS to project. Place into the class the follow using:

using Microsoft.SqlServer.Dts.Runtime;

Now, into the page load event place this code:

string pkgLocation;
Package pkgImport;
Application appImport;
DTSExecResult pkgResults;
 
pkgLocation = @"c:\temp\DtsTest.dtsx";
appImport = new Application();
pkgImport = appImport.LoadPackage(pkgLocation, null);
pkgResults = pkgImport.Execute();
 
if (pkgResults == DTSExecResult.Success)
{
    TxtEsito.text = "DTS Eseguito con successo.";
}

Also, we can see the state of job using the follow state enumeration http://msdn2.microsoft.com/en-us/library/microsoft.sqlserver.dts.runtime.dtsexecresult.aspx

submitted by Emanuele Bartolesi

Operators ?: and ??

Sun, 13 Jan 2008 18:00:24 GMT

Original code:

    string f(string inputString)
    {
        if (inputString != null)
            return inputString;
        else
            return "";
    }

operator ?

    string f(string inputString)
    {
        return (inputString != null) ? inputString : "";
    }

operator ??

    string f(string inputString)
    {
        return (inputString) ?? "";
    }

http://msdn2.microsoft.com/en-us/library/ty67wk28.aspx
http://msdn2.microsoft.com/en-us/library/ms173224.aspx

submitted by constructor

Hide automatically generated column fields in GridView

Fri, 28 Dec 2007 06:55:17 GMT

Original article can be found at http://www.mycsharpcorner.com/Post.aspx?postID=49

When you bind a GridView to an ObjectSource in ASP.NET, sometimes, you don't want to display all of the columns returned from the ObjectSource DataTable, but if you use a GridView and let it autmatically generate the columns, it becomes not a striaght forward deal to hide the individual selected columns. Here is a way to do that:

Simply catch the RowDataBound event on the GridView and if you know the index of the column to hide, just use it as follows:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.Cells.Count >= 1)
        e.Row.Cells[1].Visible = false;
}

Assuming you want to hide the second column in your automatically generated GridView.

submitted by Jacob Cook

Windows forms and ASP.NET FAQ

Fri, 28 Dec 2007 02:31:37 GMT

You'll certainly find something usefull there. It's a great resource. http://www.syncfusion.com/FAQ/WindowsForms/Default.aspx http://www.syncfusion.com/faq/aspnet/default.aspx

submitted by sotto

Cut a line into memory

Mon, 24 Dec 2007 11:51:37 GMT

By pressing CTRL+L, you can cut a line of code into memory. This is an easy way to move lines around your pages, or delete a set of lines quickly. Simple, yet useful!

submitted by Grant Merwitz

FYI To Man Manovich

Fri, 14 Dec 2007 19:12:44 GMT

Hello Man. For some reason, the form in the Comments section of the tips is not having a good design with the following configuration: - IE 6 (specifically Version: 6.0.2900.2180) - XP Professional (with SP 2) I am not sure but it may be a possible CSS issue. Just wanted to let you know about it. Mustafa Basgun mbasgun@yahoo.com

submitted by Mustafa Basgun

Easily convert string to Proper Case

Sun, 09 Dec 2007 15:17:35 GMT

This is a string helper that converts string to a proper case (capitalized first letter of each word)

Ex:
this is a test of proper case

Result:
This Is A Test Of Proper Case

Instead of using/creating a custom static method to do this, we just use built-in method of .NET though seldom use:

using System.Globalization;
using System.Threading;
 
    public static string ProperCase(string text)
    {
        CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
        TextInfo textInfo = cultureInfo.TextInfo;
        return textInfo.ToTitleCase(text);
    }

and use it like:

string properCase = ProperCase("make me complete");

That's all there is to convert our string to proper case.

submitted by Earljon Hidalgo

Referencing global namespace root

Thu, 29 Nov 2007 20:13:31 GMT

When you have something like:

using System;
 
class MyApp
{
    public class System { } // redefine a known namespace. 
 
    static void Main()
    {
        Console.WriteLine("console test"); // Error accesses MyApp.Console 
        System.Console.WriteLine("console test"); // Error accesses MyApp.Console 
    }
}
 

You will confuse the compiler. To make it work you can rename your conflicting object, or use the "global" keyword, as in:

global::System.Console.WriteLine("console test");

submitted by M.Parreira

Add Grid & SqlDataSource by hust Copy & Paste

Fri, 23 Nov 2007 18:46:00 GMT

Copy one or more columns from a table in SQL Server 2005 diagrams and paste them in asp.net page, you see, Visual Studio creates a SqlDataSource & GridView for selecting and displaying those columns from that table.

submitted by Hossein Margani

Build for larger projects

Wed, 21 Nov 2007 03:58:15 GMT

Hide the image folder and the other unnecessary folders and then compile your project.

submitted by SaSSi

Quick class refactoring (Extracting methods)

Tue, 06 Nov 2007 16:38:33 GMT

When refactoring classes, you can quickly extract code into a new method by selecting the lines of code and using the CTRL R + CTRL M (Extract method) keyboard shortcut. Visual Studio will automatically work out the scope, return type and the parameter list and allow you to enter a new name for the method.

submitted by Stephen Els

How to read GPS metadata from image

Sat, 03 Nov 2007 12:46:35 GMT

In order to read GPS (or any other) metadata from image, you can use two new objects, introduces in .NET 3.0, named BitmapMetadata and BitmapDecoder. Following code returns Geolocation coordinates of pictures, taken by camera, that supports it

using (Stream stream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
    JpegBitmapDecoder decoder = new JpegBitmapDecoder(stream, BitmapCreateOptions.None, BitmapCacheOption.None);
    BitmapMetadata meta = (BitmapMetadata)decoder.Frames[0].Metadata;
    ulong[] latitude = meta.GetQuery("/app1/ifd/gps/subifd:{ulong=2}") as ulong[];
    ulong[] longitude = meta.GetQuery("/app1/ifd/gps/subifd:{ulong=4}") as ulong[];
}

Now you should convert retrived coordinates into it's readable represenation. You can do it, by using following method.

static double ConvertCoordinate(ulong[] coordinates)
{
    int lDash = (int)(coordinates[0] - ((ulong)0x100000000));
    int lF = (int)(coordinates[1] - ((ulong)0x100000000));
    double lR = ((double)(coordinates[2] - ((ulong)0x6400000000))) / 100;
    double tRes = (lDash + (((double)lF) / 60)) + (lR / 3600);
    return (Math.Floor((double)(tRes * 1000000)) / 1000000);
}

submitted by Tamir Khason

Check whether executable is managed

Sat, 03 Nov 2007 12:41:11 GMT

In order to check wherer dll or any other executable, you want to load by using reflection is managed, you should check file version signature

string GetRuntimeVersion(string filename)
{
    const int CCH = 0x400;
    StringBuilder sb = new StringBuilder(CCH);
    int len;
    int hr = GetFileVersion(filename, sb, sb.Capacity, out len);
    if (hr == unchecked((int)0x8007000B))
        return string.Empty;
    else if (hr < 0)
        throw new Win32Exception(hr);
    else
        return sb.ToString(0, len - 1);
}

Here is the signature of GetFileVersion method

[DllImport("mscoree.dll")]
private static extern int GetFileVersion( [MarshalAs(UnmanagedType.LPWStr)] string szFilename, [MarshalAs(UnmanagedType.LPWStr)] StringBuilder szBuffer, int cchBuffer, out int dwLength);

If the assebly is not managed, the method returns COR_E_ASSEMBLYEXPECTED, else the runtime verion, this assembly was compiled.

submitted by Tamir Khason

Disable Submit button before its Click event

Fri, 02 Nov 2007 00:34:17 GMT

While submitting the form data to a server to be handled by the Click event of Submit button, it would be a good practice to disable the button. Here is a small code sample to achieve this by using the ClientScriptManager.GetPostBackEventReference method.

VB.NET:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
btnSubmit.Attributes.Add("onclick", ClientScript.GetPostBackEventReference(btnSubmit, "") & ";this.value='Submitting...'; this.disabled = true;")
End Sub

C#:

protected void Page_Load(object sender, System.EventArgs e)
{
    btnSubmit.Attributes.Add("onclick", ClientScript.GetPostBackEventReference(btnSubmit, "") + ";this.value='Submitting...';this.disabled = true;");
}

submitted by Mustafa Basgun

Publish RSS with the XML Control

Thu, 01 Nov 2007 21:16:12 GMT

The RSS control is a control that combines other controls and techniques so that you can publish RSS feed on a Web form. It uses the ASP.NET XML control, which takes the RSS feed as its input and runs it through XSLT style sheet. You can test RSS control on different feeds, ie RSS v1.0 and RSS v2.0 feeds. The version really doesn't matter because the XML is translated via the XSLT style sheet. If you need to support another RSS version, you can do so by modifying the XSLT style sheet.

submitted by Lohith Bandrehalli

Windows Forms Versus WPF

Wed, 31 Oct 2007 09:30:14 GMT

Windows Forms is legacy. Microsoft should label Windows Forms as legacy (as it has done with COM), only offer bug fixes and concentrate 100% on WPF. WPF is the future. I’ve had more fun building WPF UI than I’ve ever had with Windows Forms. Ignoring the WPF fun element, I think the WPF applications I’ve build are far superior to anything I did in Windows Forms from the perspective of usability and visualization of data. Here are a few advantages to using WPF:

Databinding in WPF is superior to what Windows Forms offers.
UI and C# business logic can be cleanly separated in WPF.
Storyboard.
Data/control templates - a much cleaner way than anything Windows Forms can offer. Styles - cool and simple. Its so easy to style all your buttons in an application to have the same look and feel.
Even if the VS designer breaks, its easy to code XAML.
UI virtualization.
I’ve got grids with 100K rows, ticking off a moving market. Performance would be dreadful if it wasn’t for UI visualization which come for free.
3D support.
Nothing scientific but, UI development feels quicker in WPF - maybe its just because a WPF application looks cooler at the end of an iteration, or maybe its because development really is quicker. I can add a User Experience engineer to my team, and with no C# knowledge he can work magic in Expression Blend and give the front-office trading application a makeover that is guaranteed to win over the business users.

submitted by Jigar

The System.Data.Design Namespace

Wed, 31 Oct 2007 06:36:05 GMT

The System.Data.Design namespace, is the smallest of the ADO.NET namespaces, which contains classes used to create typed DataSet classes, including code and parameters. This namespace is new to the .NET Framework 2.0, but the classes in this namespace were located in the System.Data namespace in previous versions of the .NET Framework. The classes are mostly used internally by ADO.NET-related functionality i.e. exposed in the Visual Studio .NET IDE, such as creating a typed DataSet from a DataAdapter dragged from the toolbox and dropped on the designer.

submitted by Lohith Bandrehalli

Which is better: Control or WebControl?

Tue, 30 Oct 2007 07:34:07 GMT

The Control class in System.Web.UI namespace is the base class for all server controls. This provides the properties, methods, and events shared by all web controls. The WebControl class in System.Web.UI.WebControls namespace derives from the Control class and adds style properties such as Font, Forecolor, and Backcolor. Microsoft recommends if your custom control contains no user interface elements then derive from Control Class. if your custom control provides a user interface, then derive from WebControl class.

submitted by Lohith Bandrehalli

Handling Errors at the Method Level

Fri, 26 Oct 2007 08:29:31 GMT

If potential errors are recoverable in the routine Use a combination of try…Catch blocks as a retry mechanism for error handling.
If useful information can be added to the exception Create and throw a new exception with the added information.
If cleanup is required Perform it in the finally block.
If potential errors are not recoverable in the routine Recovery should be handled by the calling routine and its error-handling structure.

submitted by Lohith Bandrehalli

Reading and Writing the Registry

Thu, 25 Oct 2007 20:19:03 GMT

To write to the registry use Registry.SetValue()

string keyname = "HKEY_CURRENT_USER\\Software\\CompanyName\\AppName";
Registry.SetValue(keyname, "TestString", "Hello");

To read the registry use Registry.GetValue()

// default to blank if not present 
string s = Registry.GetValue(keyname, "TestString", "").ToString(); 

submitted by Brian Kowald

Writting to Windows Application Log

Thu, 25 Oct 2007 20:11:11 GMT

To write to the windows application log use this:

using System.Diagnostics;
 
...
   
EventLog elog = new EventLog();
elog.Log = "Application";
elog.Source = "My test log program";
elog.WriteEntry("Hello, World");
elog.Close();

submitted by Brian Kowald

Move hard-coded strings to a Resource

Thu, 25 Oct 2007 17:42:10 GMT

With this light VS add-in, you can move hard-coded strings to resource files easily. All you have to do is:

right click on the string
refactor > extract to resource
select an existing resource or type a new resource name on the opened window

Using resource files is strongly recommended in .NET applications. For example, strings can be loaded faster and can be translated to other languages.

submitted by Muhammed Tahiroglu

Find a control within a control recursively

Sat, 20 Oct 2007 11:56:18 GMT

    public Control FindControlRecursive(Control Root, string Id)
    {
        if (Root.ID == Id)
            return Root;
       
        foreach (Control Ctl in Root.Controls)
        {
            Control FoundCtl = FindControlRecursive(Ctl, Id);
            if (FoundCtl != null)
                return FoundCtl;
        }
       
        return null;
    }
   
    //Example Usage 
    Label myLabel = (Label)FindControlRecursive(Page, "myLabel");

submitted by Jesal Gadhia

How to call a surrogate for Dispose() on StringBuilder objects

Sat, 20 Oct 2007 00:10:51 GMT

A typical use for the StringBuilder type looks like below:

class Program
{
    static string UseStringBuilder(string token)
    {
        StringBuilder sb = new StringBuilder();
        int i = 10;
        while (i-- > 0)
        {
            sb.Append(token + '\n');
        }
       
        string result = sb.ToString();
        return result;
    }
   
    static void Main(string[] args)
    {
        Console.WriteLine(ShowContent("first"));
        Console.WriteLine(ShowContent("second"));
    }
}

The issue with this code is that when sb goes out of scope it is mark for garbage collection, but the memory stored in it lingers until the garbage collector invokes its finalizer. That could amount to a lot of unused memory and hence might cost you some unnecessary garbage collections by the CLR. Given this behavior it would only look natural to call something like Dispose to take care of the underline memory buffer used in the StringBuilder. Unfortunately there is no Dispose method for this class, or any method to hint at freeing this unused memory in a deterministic way. The trick to get rid of this memory without invoking the finalizer is to set the Length to 0. The efficient code will become:

class Program
{
    static string UseStringBuilder (string token)
    {
        StringBuilder sb = new StringBuilder();
        int i = 10;
        while (i-- > 0)
        {
            sb.Append(token + '\n');
        }
       
        string result = sb.ToString();
        sb.Length = 0;// this is the Dispose equivalent 
        return result;
    }
   
    static void Main(string[] args)
    {
        Console.WriteLine(ShowContent("first")); // no need to call System.GC.Collect() for the unreferenced StringBuilder object 
        Console.WriteLine(ShowContent("second"));
    }
} 

submitted by decebal mihailescu

How to maintain the position of the scrollbar on postbacks (across the entire site)

Wed, 03 Oct 2007 00:12:28 GMT

In ASP.NET 1.1 it was a pain to maintain the position of the scrollbar when doing a postback operation. In ASP.NET 2.0 you can simply add the MaintainScrollPostionOnPostBack attribute to the Page directive of any specific page:

<% Page Language="C#" ... MaintainScrollPositionOnPostback="true" %>

If you would like to apply this behavior to your entire site simply modify the <pages /> entry of your <system.web /> section in your web.config file like so:

submitted by Joe Levi

Enum.IsDefined() to check submited user values

Wed, 26 Sep 2007 18:27:17 GMT

Given an enum like...

public enum MyEnum
{
    Value1,
    Value2,
    Value3
}

When you have a user submited value you need to check against an enum, you can easilly do it..

int submitedValue = 123;
if(Enum.IsDefined(typeof(MyEnum), submitedValue))
{
    ...

submitted by M.Parreira