Question

I have the following code in the front end

 <asp:Content ID="Content1" ContentPlaceHolderID="cphMain" runat="server">
        <script type="text/javascript">
            //on upload button click temporarily disables ajax to perform upload actions
            function conditionalPostback(sender, args) 
            {
                if (args.EventTarget == '<%= ((Button)frmvwMainDetail.FindControl("bttnRateUploadUpload")).UniqueID %>') {
                    args.EnableAjax = false;
                }
            }
        </script>
    ...
</asp:content>

When the page load, it’ complaining about ((Button)frmvwMainDetail.FindControl(“bttnRateUploadUpload”)).UniqueID is null value. So my question how to put some checking on this ?

Answer 1

use ClientID not UniqueID

• The control’s UniqueID property is rendered as the name attribute.

• The control’s ClientID property is rendered as the id attribute.

Do something with your code OnPageLoad:

// Define the name and type of the client scripts on the page.
    String csname1 = "PopupScript";
    Type cstype = this.GetType();

    // Get a ClientScriptManager reference from the Page class.
    ClientScriptManager cs = Page.ClientScript;

    // Check to see if the startup script is already registered.
    if (!cs.IsStartupScriptRegistered(cstype, csname1))
    {
      String cstext1 = "alert('Hello World:"+ bttnRateUploadUpload.ClientID + "');";
      cs.RegisterStartupScript(cstype, csname1, cstext1);
    }