Question

I need a help with a sql exceptin of inserting duplicate key into database.
I cause the exception deliberatly to not insert the duplicit record into database.

In code behind I have this code:

Protected Sub SqlDataSource3_Inserting(sender As Object, e As SqlDataSourceCommandEventArgs)
    Try

    Catch ex As SqlException

    End Try
End Sub

But I don’t know what to write into the Try...Catch block. I just want to display a MessageBox with text You are already a member of this group. insted of error page.

This is my server code:

<asp:SqlDataSource ID="SqlDataSource3" OnInserted="SqlDataSource3_Inserted" OnInserting="SqlDataSource3_Inserting" runat="server" ConnectionString="<%$ ConnectionStrings:MotWebConnectionString %>" 
    InsertCommand="INSERT INTO [GroupMembers] ([UserName], [GroupId]) VALUES (@UserName, @GroupId)" >

<asp:SqlDataSource ID="SqlDataSource3" OnInserted="SqlDataSource3_Inserted" OnInserting="SqlDataSource3_Inserting" runat="server" ConnectionString="<%$ ConnectionStrings:MotWebConnectionString %>" 
    InsertCommand="INSERT INTO [GroupMembers] ([UserName], [GroupId]) VALUES (@UserName, @GroupId)" >

Answer 1

The exception will not be raised in the event handler; instead you should do something like:

Protected Sub SqlDataSource3_Inserted(sender As Object, e As SqlDataSourceStatusEventArgs)
   If e.Exception IsNot Nothing Then
      ' Handle exception here
      ' Prevent exception from being re-thrown
      e.ExceptionHandled = True
   End If
End Sub