Hello All,

 I have 5 rows of 6 column textboxes in my gridview, on the text change event of the textbox i am doing some calculations with the values in the textbox.Everything works fine.The problem is,after the calculation the cursor  gets lost.I want the cursor to be either in the same textbox, or to the next textbox if tab is pressed or in any other textbox where the user clicks after changing the values.

can any one help me in this.
 

Are you doing a postback to perform these calculations?

Do you need to do these calculations on the server? If not, then javascript would be a much better choice here. But if you must do the calculations on the server then you should use a PageMethod.

A PageMethod is like calling a webservice from javascript, but the method resides in your code-behind, you can call it from javascript, and no postback occurs.

To create a PageMethod there are a few things you must do.

1. Set EnablePageMethods="True" in your ScriptManager

2. Create a public static method in your code behind with the attribute [System.Web.Services.WebMethod() ]

3. The return value of this method can be of any type, but in your case should use a string to return to the textbox.

4. In your javascript create 3 functions:

function CallYourPageMethod(c) { // c is optional, but it will allow you to pass a reference to your control into the function
  PageMethods.NameOfPublicStaticMethod(parameter1, parameters2, ... parameterN, onSuccessCallBack, onFailureCallBack, userContext);
}

function onSuccessCallBack(result, userContext) {
  if (result) {
    $get(userContext.id).innerText = result;
  }
  else {
    alert("An unexpected error occurred");
  }
}

function onFailureCallBack(error, userContext) {
  if (error) {
    alert("The control " + userContext.id + " caused the following error:\n" + error.get_message());
  }
  else {
    alert("An unexpected error occurred");
  }
}

A bit more detail about the code above will help too. (No idea why this turned blue).

Good luck!

I wonder how this helps my problem 

By the sound of your problem you were triggering a postback when your textbox changed. So when the postback finished the textbox no longer had focus. This way, the postback will never occur, and the focus will remain where you want it.

Not to mention, the page will be far more responsive, and your server will thank you for not having to postback your entire page (and all that gridview data) ever time a user goes from one textbox to another.

It helps your problem in more than one way.

http://forums.asp.net/p/1249475/2308333.aspx 

Sets the browser focus to the specified control

http://www.asp.net/AJAX/Documentation/Live/mref/O_T_System_Web_UI_ScriptManager_SetFocus.aspx

You can use the following code to set the focus:
 

ScriptManager sm = ScriptManager.GetCurrent(this);
sm.SetFocus(myTextBox);

To set focus and select text of a you have to use the following:
 

ScriptManager.RegisterStartupScript(this, this.GetType(), "selectAndFocus", "$get('" + myTextBox.ClientID + "').focus();$get('" + myTextBox.ClientID + "').select();", true);

http://forums.asp.net/t/1099345.aspx

http://forums.asp.net/t/1199709.aspx