Archive for the ‘Tips & Tricks’ Category

Unable to launch the ASP.NET Development server because port ‘1900’ is in use

The Problem

You are coding away, Visual Studio locks up for one of it’s many reasons, and reopen your project and run it again. You then get the “Unable to launch the visual studio development server because port 9452 is in use” error

The Cause

When Visual Studio crashed, the Web Server did not, so basically it thinks you are trying to run two instances at the same time, which is not allowed.

The Solution

Open up the process manager, go to the Processes tab, and select “WebDev.WebServer40.exe” and click “End Process”. Then try running your project again. Visual Studio will now start the project fresh and the problem should go away.


Or try this



Hope it helps !

Pound Symbol

November 7, 2012 Leave a comment

To type pound symbol press ALT + 0163

Categories: Tips & Tricks

Expression for Email Address validation in C#

October 13, 2011 Leave a comment

<asp:TextBox ID=”txtEmail” runat=”server”></asp:TextBox>

<asp:RegularExpressionValidator ValidationExpression=”^([a-zA-Z0-9_\-\+\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$” ID=”rxpEmail” runat=”server” ErrorMessage=”Email Address is not valid” ControlToValidate=”txtEmail”>


For Online Testing

Categories: Tips & Tricks

Server.Transfer v/s Response.Redirect

January 1, 2011 Leave a comment

Response.Redirect(“newpage.aspx”) and Server.Transfer(“newpage.aspx”)

  • Response.Redirect involves a roundtrip to the server whereas Server.Transfer conserves server resources by avoiding the roundtrip. It just changes the focus of the webserver to a different page and transfers the page processing to a different page.
  • If you are using Server.Transfer then you can directly access the values, controls and properties of the previous page which you can’t do with Response.Redirect.
  • Response.Redirect changes the URL in the browser’s address bar. So they can be bookmarked. Whereas Server.Transfer retains the original URL in the browser’s address bar. It just replaces the contents of the previous page with the new one.
  • Response.Redirect can be used for both .aspx and html pages whereas Server.Transfer can be used only for .aspx pages and is specific to ASP and ASP.NET.
  • Response.Redirect can be used to redirect a user to an external websites. Server.Transfer can be used only on sites running on the same server. You cannot use Server.Transfer to redirect the user to a page running on a different server.
Categories: ASP.NET, Tips & Tricks