datagridview数据验证

private void dataGridView1_CellValidating(object sender,
DataGridViewCellValidatingEventArgs e)
{
// Validate the CompanyName entry by disallowing empty strings.
    if (dataGridView1.Columns[e.ColumnIndex].Name == "CompanyName")
{
if (e.FormattedValue.ToString() == String.Empty)
{
dataGridView1.Rows[e.RowIndex].ErrorText =
"Company Name must not be empty";
e.Cancel = true;
}
}
}