一键调用javascript和c＃方法

Question

I have a method in javascript and a method in c#, now with a click on a button I would like to call them both.

First I would like to call the c# method named as 'Find_Direction' since it gets to inputs onclick and then I will call after the javascript method named as calcRoute .

I was trying this, but without any luck:

<asp:Button id="Button1" UseSubmitBehavior="False" value="GetDirections" onclick="calcRoute" OnClientClick="Find_Direction" runat="server"/>

The following error popped up :

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS1061: 'ASP.findroute_aspx' does not contain a definition for 'calcRoute' and no extension method 'calcRoute' accepting a first argument of type 'ASP.findroute_aspx' could be found (are you missing a using directive or an assembly reference?)

Answer 1

Your are specifying javascript function name in onClick event. So put here C# function name

C# code:

 protected void  Find_Direction (object sender, EventArgs e)
 {
   // do your work

   // Register your javascript function

    Page.ClientScript.RegisterStartupScript(this.GetType(), "script", "  <script>calcRoute();</script>");
 }

your markup :

<asp:Button id="Button1" value="GetDirections" onclick="Find_Direction" runat="server"/>

Case 2 : Call javascript function before server side function

Javascript function

 function calcRoute() {

        alert('test')
        return true;
    }

your markup

 <asp:Button id="Button1" value="GetDirections" onclick="Find_Direction " OnClientClick="return Find_Direction()" runat="server"/>

By this you can call javascript function then server side but make sure you are returning true from javascript function for calling your server side function.

I Hope, now you can solve your problem. :)

Answer 2

You need an event handler in your code-behind (the aspx.cs or aspx.vb file) called calcRoute .

If you want the JS to execute first, you should be able to do it the way you're doing it, with OnClientClick which points to a JS function and OnClick which points to a C#/VB method (event handler).

If you want to be sure that JS gets called after your C# code, you should handle the click on the backend, and then send the JS back to the browser by registering a startup script. This will cause a full post-back, unless you're using an update panel. In your event handler, you can register a startup script with Page.RegisterStartupScript to send a javascript command back to the browser. In this case, you won't want to use OnClientClick at all.