标题：请狐爹帮忙看看动态导出字段报错

Dim zd,zd1 As String
For i As Integer =  Tables("订单").LeftCol To Tables("订单").RightCol
    zd = zd & Tables("订单").Cols(i).Name & ","
Next
zd1 = zd.Trim(",")
Output.Show(zd.Trim(","))

Dim ex As New Exporter
ex.SourceTableName = "订单" '指定导出表
ex.FilePath = "D:\订单.xls" '指定目标文件
ex.Format = "Excel" '导出格式为Excel
ex.Fields =  zd1 '指定导出字段
ex.Export() '开始导出