实现 DataGird 的升序和降序排列

代码如下：

Private Sub dgdBook_SortCommand()Sub dgdBook_SortCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) Handles dgdBook.SortCommand

Dim SortExpression As String = dgdBook.Attributes("SortExpression").ToString '获取原来的排序字段
Dim SortDirection As String = dgdBook.Attributes("SortDirection").ToString '获取原来的排序方向

If e.SortExpression.ToString = SortExpression Then
SortDirection = IIf(SortDirection = "ASC", "DESC", "ASC") '点击同一列标题改变排列方向
Else '点击不同列标题改变排列字段，升序排序
SortExpression = e.SortExpression.ToString
SortDirection = "ASC"
End If

dgdBook.Attributes("SortExpression") = SortExpression '赋予新的排序字段
dgdBook.Attributes("SortDirection") = SortDirection '赋予新的排序方向

BindDataGrid()
End Sub