get submit button id

Question

Hi
In Asp.net form I have dynamically generated buttons, every button submits a form to, is there a way to get which button was submit the form in page load event?

Answer 1

Use CommandArgument property to determine which button submits the form.

Edit : I just realized, you said you need this at PageLoad, this works only for Click server side event, not for PageLoad.

Answer 2

The sender argument to the handler contains a reference to the control which raised the event.

private void MyClickEventHandler(object sender, EventArgs e)
{
    Button theButton = (Button)sender;
    ...
}

Edit: Wait, in the Load event? That's a little tricker. One thing I can think of is this: The Request's Form collection will contain a key/value for the submitting button, but not for the others. So you can do something like:

protected void Page_Load(object sender, EventArgs e)
{
    Button theButton = null;
    if (Request.Form.AllKeys.Contains("button1"))
        theButton = button1;
    else if (Request.Form.AllKeys.Contains("button2"))
        theButton = button2;
    ...
}

Not very elegant, but you get the idea..

Answer 3

protected void Page_Load(object sender, EventArgs e) {            
    string id = "";
    foreach (string key in Request.Params.AllKeys) {
        if (!String.IsNullOrEmpty(Request.Params[key]) && Request.Params[key].Equals("Click"))
            id = key;
    }
    if (!String.IsNullOrEmpty(id)) {
        Control myControl = FindControl(id);
        // Some code with myControl
    }
}

Answer 4

This won't work if your code is inside a user control:

Request.Form.AllKeys.Contains("btnSave") ...

Instead you can try this:

if (Request.Form.AllKeys.Where(p => p.Contains("btnSave")).Count() > 0)
{
    // btnSave was clicked, your logic here
}