Bidirectional Sort and Choosing a Row to Update or Delete by Click Any Cell in DataGrid

First, two methods to realize the bidirectional sorts including the ascendant sort order and the descendant sort order in the DataGrid through storing the sort expression and the sort direction by means of attributes and viewstate are summarized in order that the users browse and look up more conveniently; Second, the method to choose a row by click any cell in the DataGrid is given in order that the users could operate more conveniently; Third, the methods to update or delete the selected record row in the DataGrid from Web forms controls are given to ensure data validation.