c# 点击DatagridView标题头单元格，按所点击单元格排序。

</pre><pre name="code" class="csharp">public int i = 1;
/// <summary>
/// 点击datagridview标题头单元格，按被点击单元格进行排序
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void mainView_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
DataGridViewColumn newColumn = mainView.Columns[e.ColumnIndex];
DataGridViewColumn oldColumn = mainView.SortedColumn;
ListSortDirection direction;
if (oldColumn != null)
{
if (oldColumn == newColumn && mainView.SortOrder == System.Windows.Forms.SortOrder.Ascending)
{
i++;

if (1%2==0)
{
direction = ListSortDirection.Descending;
}
else
{
direction = ListSortDirection.Ascending;
}
}
else
{
direction = ListSortDirection.Descending;
oldColumn.HeaderCell.SortGlyphDirection = System.Windows.Forms.SortOrder.None;
}
}
else
{
direction = ListSortDirection.Ascending;
}
mainView.Sort(newColumn, direction);
newColumn.HeaderCell.SortGlyphDirection =
direction == ListSortDirection.Ascending ? System.Windows.Forms.SortOrder.Ascending : System.Windows.Forms.SortOrder.Descending;

}