Error Handling Automatic Operations

RadGrid can fire three events after an automatic action occurred:

• ItemUpdated

• ItemInserted

• ItemDeleted

protected void RadGrid1_ItemUpdated(object source, Telerik.Web.UI.GridUpdatedEventArgs e)
{
    if (e.Exception != null)
    {
        e.KeepInEditMode = true;
        e.ExceptionHandled = true;
        DisplayMessage("Product " + e.Item["ProductID"].Text + " cannot be updated. Reason: " + e.Exception.Message);
    }
    else
    {
        DisplayMessage("Product " + e.Item["ProductID"].Text + " updated");
    }
}
protected void RadGrid1_ItemInserted(object source, GridInsertedEventArgs e)
{
    if (e.Exception != null)
    {
        e.ExceptionHandled = true;
        e.KeepInInsertMode = true;
        DisplayMessage("Product cannot be inserted. Reason: " + e.Exception.Message);
    }
    else
    {
        DisplayMessage("Product inserted");
    }
}
protected void RadGrid1_ItemDeleted(object source, GridDeletedEventArgs e)
{
    if (e.Exception != null)
    {
        e.ExceptionHandled = true;
        DisplayMessage("Product " + e.Item["ProductID"].Text + " cannot be deleted. Reason: " + e.Exception.Message);
    }
    else
    {
        DisplayMessage("Product " + e.Item["ProductID"].Text + " deleted");
    }
}

private void DisplayMessage(string text)
{
    RadGrid1.Controls.Add(new LiteralControl(text));
}

Protected Sub RadGrid1_ItemUpdated(ByVal source As Object, ByVal e As Telerik.Web.UI.GridUpdatedEventArgs) Handles RadGrid1.ItemUpdated
    If Not (e.Exception Is Nothing) Then
        e.KeepInEditMode = True
        e.ExceptionHandled = True
        DisplayMessage("Product " & e.Item("ProductID").Text & " cannot be updated. Reason: " & e.Exception.Message)
    Else
        DisplayMessage("Product " & e.Item("ProductID").Text & " updated")
    End If
End Sub 'RadGrid1_ItemUpdated

Protected Sub RadGrid1_ItemInserted(ByVal source As Object, ByVal e As GridInsertedEventArgs) Handles RadGrid1.ItemInserted
    If Not (e.Exception Is Nothing) Then
        e.ExceptionHandled = True
        e.KeepInInsertMode = True
        DisplayMessage("Product cannot be inserted. Reason: " & e.Exception.Message)
    Else
        DisplayMessage("Product inserted")
    End If
End Sub 'RadGrid1_ItemInserted

Protected Sub RadGrid1_ItemDeleted(ByVal source As Object, ByVal e As GridDeletedEventArgs) Handles RadGrid1.ItemDeleted
    If Not (e.Exception Is Nothing) Then
        e.ExceptionHandled = True
        DisplayMessage("Product " + e.Item("ProductID").Text + " cannot be deleted. Reason: " + e.Exception.Message)
    Else
        DisplayMessage("Product " + e.Item("ProductID").Text + " deleted")
    End If
End Sub 'RadGrid1_ItemDeleted

Private Sub DisplayMessage(ByVal text As String)
    RadGrid1.Controls.Add(New LiteralControl([text]))
End Sub 'DisplayMessage

The default behavior of Telerik RadGrid is tolet the DataSource control rise an exceptionwhen error occurs when inserting/updating/deleting. To prevent this exception you should handle the corresponding event and in case (e.Exception != null) or (Not e.Exception Is Nothing) you should set e.ExceptionHandled to true and display error message.

protected void RadGrid1_ItemDeleted(object source, GridDeletedEventArgs e)
{
      if (e.Exception != null)
      {
         e.ExceptionHandled = true;
         DisplayMessage("Product " + e.Item["ProductID"].Text + " cannot be deleted. Reason: " + e.Exception.Message);
      }
      ....
}

Protected Sub RadGrid1_ItemDeleted(ByVal source As Object, ByVal e As GridDeletedEventArgs) Handles RadGrid1.ItemDeleted
    If Not (e.Exception Is Nothing) Then
        e.ExceptionHandled = True
        DisplayMessage("Product " + e.Item("ProductID").Text + " cannot be deleted. Reason: " + e.Exception.Message)
    End If
...............

End Sub