How do I add an ASP.NET control inside an ASCX to an external RequiredFieldValidator programmatically?

I have a drop-down list inside a user control (ASCX) that I want to validate from the page on which I've placed the ASCX, but when I set the ControlToValidate to the drop-down list the page complains that it can't be found. Thanks for any help/suggestions.

From stackoverflow

• The only way I know to do this is to do this in your user control class:

  
  [ValidationProperty("Foo")]
  public class MyUserControl : UserControl
  {
       public string Foo
       {
            get { return(yourDropDown.SelectedValue); }
       }
  }
  

  And then in the page you place the user control on:

  
  <asp:RequiredFieldValidator ControlToValidate="yourUserControlName" runat="server" ErrorMessage="You are required to make a selection" />
  

  Not quite the same thing, but that's the only workaround that I know.

  mkelley33 : Thank you for the help.

  Adam Smith : This one worked for me, however it does a postback before it validates which is unlike the other RequiredFieldValidators that are validating the regular textboxes, any suggestions on getting them to work all at the same time.

  mgroves : Did you Chris Mullins's answer and expose the whole dropdown instead of just the SelectedValue? Other than that, you may have to write some custom javascript.

• Expose the dropdown list with a public property in your user control:

  public DropDownList DropDownToValidate
      {
       get
       {
        return ddlTest;
       }
      }
  

  Then use the UniqueID of the exposed Dropdown to set the control to validate in the page load of the page on which you dropped the user control:

  protected void Page_Load(object sender, EventArgs e)
  {
  
   RequiredFieldValidator1.ControlToValidate = WebUserControl1.DropDownToValidate.UniqueID;
  }
  

  mkelley33 : Thank you! I couldn't get it to work for a user control nested within a user control, but I appreciate all of the help.

• I think the best way to validate user control is to have public method inside your user control:

  public void Validate() {
    reqRecipientName.Validate();
    reqRecipientMail.Validate();
    valRecipientMail.Validate();
    reqRecipientPhone.Validate();
  }
  

  where reqRecipientName, reqRecipientMail... are ID of validators (they are also insice ascx). And then on Page inside submit method call controlId.Validate(); This works for me.