private void dataGridView1_Sorted(object sender, EventArgs e)
{
string _sortStr = dataGridView1.SortedColumn.Name; //排序列
SortOrder _so = dataGridView1.SortOrder; //排序方向
if (_so == SortOrder.Ascending)
_sortStr += " asc";
else
_sortStr += " desc";
DataView _dv = dt.DefaultView;
_dv.Sort = _sortStr; //排序
dt = _dv.ToTable(); //将排序后的datatable赋给 dt
}