How to disable button in row databound event in gridview?

Question

i want to disable button in row data bound . when its text or value is 'Waiting for Approval'. im getting this error . Object reference not set to an instance of an object.// button.Enabled = true;

protected void GridCategoryWise_RowDataBound(object sender, GridViewRowEventArgs e)
    {

        if (e.Row.RowType != DataControlRowType.DataRow)
        {
            return;
        }

        Button button = (Button)e.Row.FindControl("btnReportedlink");

        string Id =((DataRowView)e.Row.DataItem)["ReportLinks"].ToString();

        if (Id == "Waiting for Approval")
        {
            button.Enabled = false;
        }
        else
        {
            button.Enabled = true;
        }

    }

my aspx

<asp:TemplateField HeaderText="Reportd Link"  ItemStyle-HorizontalAlign="center" >
     <ItemTemplate>
         <button onclick="window.open('<%#Eval("ReportLinks")%>', '_blank');" title='<%#Eval("ReportLinks")%>' id="btnReportedlink" runat="server"> Link</button>
         </ItemTemplate>
    <ItemStyle HorizontalAlign="Left" />
</asp:TemplateField>

Answer 1

Why are you using the HTML <button /> element ? use <asp:button /> web server control from asp.net for a better control over reading and disabling the server controls.

Use the OnClientClick property to specify additional client-side script that executes when a Button control's Click event is raised.

<ItemTemplate>
   <asp:button onclientclick="javascript:window.open('<%#Eval("ReportLinks")%>', '_blank');"
        text='<%#Eval("ReportLinks")%>'   id="btnReportedlink" runat="server"/>
</ItemTemplate>

With the above setup, now you will be able to access the button in row data bound event with NO more object references error.

Answer 2

use DataBinder work fine

protected void GridCategoryWise_RowDataBound(object sender, GridViewRowEventArgs e)
    {

        if (e.Row.RowType != DataControlRowType.DataRow)
        {
            return;
        }

        Button button = (Button)e.Row.FindControl("btnReportedlink");

    string Id = Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "ReportLinks"));

        if (Id == "Waiting for Approval")
        {
            button.Enabled = false;
        }
        else
        {
            button.Enabled = true;
        }

    }