当与asp.net Webforms中的禁用按钮代码一起使用时，javascript确认警报不起作用

Question

I have a webform with a submit button like this

<asp:Button ID="btnSub" runat="server" Text="submit" OnClientClick="return processSub();" />

The javascript function it calls is like this

function processSub(){

    var btnId = '<%= btnSub.ClientID %>'

    var userSelection = confirm('Are you sure you wish to submit');
    if (userSelection){
         document.getElementById(btnId).setAttribute("disabled","disabled");
         return true;
    } else {
         return false;
    }
}

Now I want to disable the submit button when the user clicks submit. But when I call the code to set the attribute to disabled the submit doesn't happen. When I comment this line document.getElementById(btnId).setAttribute("disabled","disabled"); in the IF block, it works and continues with the submit.

Why is this so and how do I get it to work? I am not using any JavaScript library and don't want to as well.

Thanks.

Answer 1

Even though there is no OnClick specified on the button, it will still do a form post (PostBack) when it is clicked. You set the disabled state with javascript, but immediately after a PostBack occurs therefore resetting the Button to it's original state.

if you want to disable the button you can set it in code begind after the user confirmes.

<asp:Button ID="btnSub" runat="server" Text="submit" OnClientClick="return processSub();" 
    OnClick="btnSub_Click" />

protected void btnSub_Click(object sender, EventArgs e)
{
    //disable the button
    btnSub.Enabled = false;
}

Answer 2

通过js提交表单，然后返回if语句

document.forms[0].submit();