title: Find Control in asp:repeater on button click event
body: <p>I have a dropdown list inside a asp:repeater item template.
  how can I get its value on button click event.</p>
  
  <pre><code>&lt;asp:Repeater runat="server" ID="WorkflowListAfter" onitemcreated="WorkflowListAfterItemCreated"&gt;
      &lt;ItemTemplate&gt;
           &lt;asp:DropDownList ID="ddlWorkflowMembers" runat="server" DataTextField="MemberName" DataValueField="MemberID"&gt;
      &lt;/ItemTemplate&gt;
  &lt;/asp:Repeater&gt;
  
  protected DropDownList ddlWorkflowMembers = new DropDownList();
  protected void WorkflowListAfterItemCreated(object sender, RepeaterItemEventArgs e)
  {
      ddlWorkflowMembers = (DropDownList) e.Item.FindControl("ddlWorkflowMembers");
  }
  protected void BtnSaveClick(object sender, EventArgs e) {
      if (ddlWorkflowMembers.SelectedItem == null) return;
  }
  </code></pre>
  
  <p>the code above is working at first time but after postback ddlWorkflowMembers is always null expersion.</p>