Validation

RELATED VIDEOS
Validation with RadGridView for WinForms In this video you will learn how to use the event-based Validation functionality in RadGridView for WinForms. Learn how to use the CellValidating and RowValidating events to ensure user input is valid. (Runtime: 08:47)

To prevent invalid input, wire the ValueChanging and ValueChanged events of the grid and add custom validation logic. Below is a simple example that demonstrates how to reject strings longer than 10 characters:

Handling the value changed event

• C#
• VB.NET

void radGridView1_ValueChanging(object sender, Telerik.WinControls.UI.ValueChangingEventArgs e)
{
    if (e.NewValue.GetType() == typeof(string))
    {
        if (e.NewValue.ToString().Length > 10)
        {
            {
                e.Cancel = true;
            }
        }
    }
}

Private Sub RadGridView1_ValueChanging(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.ValueChangingEventArgs) Handles RadGridView1.ValueChanging
    If e.NewValue.GetType() Is GetType(String) Then
            If e.NewValue.ToString().Length > 10 Then
                If True Then
                    e.Cancel = True
                End If
            End If
        End If
    End Sub