动态改变Gridview列的显示顺序

[k144521]

我用的Dexexpress控件，它可以改变列的顺序
我先把改变后的顺序存下来怎么做啊
我这样做不行啊
For i As Integer = 0 To GridView.Columns.Count - 1
If FormatStr = "" Then

If GridView.Columns(i).Visible = True Then

FormatStr = GridView.Columns(i).FieldName
a = GridView.Columns(i).AbsoluteIndex
End If
Else
If GridView.Columns(i).Visible = True Then
FormatStr = FormatStr & "," & GridView.Columns(i).FieldName
a = GridView.Columns(i).AbsoluteIndex
End If
End If
Next