title: ImageButton is not being enabled when using AsyncPostBackTrigger in ajax update panel in asp.net
body: <p>i am using asp.net with c#. i have two image buttons : open and delete.
  By default they are disabled i.e. <code>imgOpen.Enabled = false; imgDelete.Enabled = false;</code>.
  I have a GridView which shows search results from table. GridView contains a radio button which when selected, should enable Open and delete image button.
  if I won't use ajax update panel, then every time i select a radio button my page reloads and it's quite disturbing and not friendly.</p>
  
  <pre><code>&lt;asp:TemplateField&gt;
       &lt;ItemTemplate&gt;
            &lt;asp:UpdatePanel ID="updateRadioButton" runat="server"&gt;
                &lt;ContentTemplate&gt;
                    &lt;asp:RadioButton ID="rdoBtnFileOption" runat="server" OnCheckedChanged="rdoBtnFileOption_CheckedChanged"  AutoPostBack="true" /&gt;
                 &lt;/ContentTemplate&gt;
                 &lt;Triggers&gt;
                 &lt;asp:AsyncPostBackTrigger ControlID="rdoBtnFileOption" EventName="CheckedChanged" /&gt;
                 &lt;/Triggers&gt;
            &lt;/asp:UpdatePanel&gt;
       &lt;/ItemTemplate&gt;
  &lt;/asp:TemplateField&gt;
  
  
  
  protected void rdoBtnFileOption_CheckedChanged(object sender, EventArgs e)
      {
          imgOpen.Enabled = true;
          imgDelete.Enabled = true;
  
          RadioButton curretnRdo = sender as RadioButton;
          GridViewRow currentRow = (GridViewRow)curretnRdo.NamingContainer;
          int index = currentRow.RowIndex;
          try
          {
              foreach (GridViewRow grv in grdSearchResults.Rows)
              {
                  if (grv.RowType == DataControlRowType.DataRow &amp;&amp; grv.RowIndex != index)
                  {
                      RadioButton rdo = new RadioButton();
                      rdo = (RadioButton)(grv.FindControl("rdoBtnFileOption"));
                      rdo.Checked = false;
                  }
              }
          }
          catch (Exception ex)
          {
              form.MessageBox.Show(ex.Message, "Error", form.MessageBoxButtons.OK, form.MessageBoxIcon.Error);
          }
  
      }
  </code></pre>
  
  <p>These two line are not working for me.   </p>
  
  <pre><code>imgOpen.Enabled = true;
  imgDelete.Enabled = true;
  </code></pre>
  
  <p>Please Suggest any approach.
  I hope i am quite clear.</p>