title: Validation on DataTable when new row is added
body: <p>When a new row was added programmatically using an auto generated method on my strongly typed DataTable, How can I fire my custom validation which validate the maxleng of my field?</p>
  
  <p>My client (C#)</p>
  
  <pre><code>DAL.ImportMarcDataSet.PublicationsRow newRow = importMarcDataSet.Publications.NewPublicationsRow(); 
  
  newRow.CallNumber ="QA76.76.A65";
  newRow.Title = "Programming WCF services";
  newRow.ISBN = "0596526997";
  
  importMarcDataSet.Publications.AddPublicationsRow(newRow);
  </code></pre>
  
  <p>My Data Access Layer (VB)</p>
  
  <pre><code>Partial Class ImportMarcDataSet
      Partial Class PublicationsDataTable
          Private Sub CallNumberMaxLength(ByVal pRow As PublicationsRow)
              If pRow.CallNumber.Length &gt; 25 Then
                  pRow.SetColumnError("CallNumber", "The value entered is over the maximum length")
              Else
                  pRow.SetColumnError("CallNumber", "")
              End If
          End Sub
  'this event is ok when user made changes to the CallNumber column of the current row
         Private Sub PublicationsDataTable_ColumnChanged(ByVal sender As Object, ByVal e As System.Data.DataColumnChangeEventArgs) Handles Me.ColumnChanged
              If e.Column Is Me.CallNumberColumn Then
                  CallNumberMaxLength(e.Row)
              End If
          End Sub
      End Class
  End Class
  </code></pre>