您可以处理日历的 SelectionChanged 事件,然后从那里调用文本框的 textChanged 事件,该事件又会更新 gridview,如下所示:
protected void MyCalendar_SelectionChanged(object obj, EventArgs e)
{
MyTextbox.Text = MyCalendar.SelectedDate.ToShortDateString();
TextBox_TextChanged(null, EventArgs.Empty);
}