數據輸入錯誤提示

using DevExpress.XtraEditors.Controls;

private void dateEdit1_Validating(object sender, System.ComponentModel.CancelEventArgs e) {
   DateTime currentValue = (sender as DateEdit).DateTime;
   if(currentValue.Month != DateTime.Today.Month || currentValue.Year != DateTime.Today.Year)
      e.Cancel = true;
}

private void dateEdit1_InvalidValue(object sender, InvalidValueExceptionEventArgs e) {
   e.ExceptionMode = DevExpress.XtraEditors.Controls.ExceptionMode.NoAction;
   MessageBox.Show("Enter a date within the current month.", "Error");
}