Insert ClientScript for Asp.net server Controls

[siri]

Hi,How to Insert Javascript code for asp.net server controls like <asp:button> ,dropdown and so on.

[aspnetguy]

you can insert javascript in 2 ways.1. attach javascript to eventASPX

<asp:Button id="Button1" runat="server" text="Button 1"/>

Codebehind

Button1.Attributes.Add("onclick","yourJavaScriptFunction()");

2. Register a Client Script

this.RegisterClientScriptBlock("scriptKey","<script type=\"text/javascript\">/*your javascript code here*/</script>");

[jesh]

And a third way:ASPX

ScriptLiteral1.Text = "<script type=\"text/javascript\">document.getElementById(\"Button1\").onclick=myclickhandler;</script>";

But aspnetguy's first solution is probably the best.

[aspnetguy]

Ok here is a fourth way

<asp:Button id="Button1" runat="server" text="Button 1" OnClientClick="yourFunction()" />

[siri]

Ok here is a fourth way

<asp:Button id="Button1" runat="server" text="Button 1" OnClientClick="yourFunction()" />

Hi ASPNETGuy,The above code works but still it causes postback.How can PostBack be avoided ?

[aspnetguy]

if oyu want to avoid postback you have a couple options. You can not use a server control in the first place anf just use

<input type="button" value="Button 1" id="Button1" onclick="yourFunction()"/>

or you can tell the button not to postback

...JS codefunction youFunction() {  if(something) {	return true'  }  else {	return false;  }}...ASPX...<asp:Button id="Button1" runat="server" text="Button 1" OnClientClick="return yourFunction()" />

If your js function returns false it will not postback and the serverside function will not fire.

[jesh]

Also keep in mind that the Button control renders out as a submit button (<input type="submit">) which will submit your form by default.Another option would be to use a LinkButton or a HyperLink if you need the control to run at server and then style that link to look like a button.

[siri]

if oyu want to avoid postback you have a couple options. You can not use a server control in the first place anf just use

<input type="button" value="Button 1" id="Button1" onclick="yourFunction()"/>

or you can tell the button not to postback

...JS codefunction youFunction() {  if(something) {	return true'  }  else {	return false;  }}...ASPX...<asp:Button id="Button1" runat="server" text="Button 1" OnClientClick="return yourFunction()" />

If your js function returns false it will not postback and the serverside function will not fire.

Hi aspnet guy,I have used the following code:<asp:Button id="Button2" runat="server" text="Button 1" OnClientClick="demo()" />Here is my javascript ocde:<script type = "text/javascript"> function demo() { return window.confirm("Are you sure"); } </script>When I click on cancel even then it postbacks to the server . how to avoid it ?

[aspnetguy]

use this

<asp:Button id="Button2" runat="server" text="Button 1" OnClientClick="return demo()" />

[siri]

Hi aspnet guy,I have used the following code:<asp:Button id="Button2" runat="server" text="Button 1" OnClientClick="demo()" />Here is my javascript ocde:<script type = "text/javascript"> function demo() { return window.confirm("Are you sure"); } </script>When I click on cancel even then it postbacks to the server . how to avoid it ?

Thanks for the code. It's working