How do you determine which validator failed?

Question

I am working with a page and I am getting an Page.IsValid = false and I am trying to determine which control is causing the validation problem.

Answer 1

Credit to Steven for this answer, but I had to make some changes for it to work as this.Validators.Where() had some problems.

using System.Linq;  List<IValidator> errored = this.Validators.Cast<IValidator>().Where(v => !v.IsValid).ToList(); 

Answer 2

In code (page_load), you can do this:
(per MSDN: http://msdn.microsoft.com/en-US/library/dh9ad08f%28v=VS.80%29.aspx)

If (Me.IsPostBack) Then     Me.Validate()     If (Not Me.IsValid) Then         Dim msg As String         ' Loop through all validation controls to see which          ' generated the error(s).         Dim oValidator As IValidator         For Each oValidator In Validators             If oValidator.IsValid = False Then                 msg = msg & "<br />" & oValidator.ErrorMessage             End If         Next         Label1.Text = msg     End If End If 

In the markup, you can...

• You can put "text" on your validator (like an asterisk...)
• Or use a validation_summary control (which requires an error message on your validator)...