' Override OnMouseClick in a class derived from DataGridViewCell to  
' enter edit mode when the user clicks the cell.  
Protected Overrides Sub OnMouseClick( _
    ByVal e As DataGridViewCellMouseEventArgs)

    If MyBase.DataGridView IsNot Nothing Then 

        Dim point1 As Point = MyBase.DataGridView.CurrentCellAddress
        If point1.X = e.ColumnIndex And _
            point1.Y = e.RowIndex And _
            e.Button = MouseButtons.Left And _
            Not MyBase.DataGridView.EditMode = _
            DataGridViewEditMode.EditProgrammatically Then 

            MyBase.DataGridView.BeginEdit(True)

        End If 
    End If 
End Sub