主题：导出EXCEL文件时如何只导出可见列

Dim lblDatatable As WinForm.Label = e.Form.Controls("lblDatatable")
Dim dt As Table = e.Form.Controls("Table1").Table
Dim str As String = _tables3_ & Format(Date.Now, "yyyyMMddHHmmss") & ".xls"
Dim Book As New XLS.Book '定义一个Excel工作簿
Dim Sheet As XLS.Sheet = Book.Sheets(0) '引用工作簿的第一个工作表
Dim Style As Xls.Style = Book.NewStyle '新建一个样式
Style.BackColor = Color.Red '样式的背景颜色设为红色
For c As Integer = 0 To dt.Cols.Count -1 '添加列标题
    Sheet(0, c).Value = dt.Cols(c).Name
Next
For r As Integer = 0 To dt.Rows.Count - 1 '填入数据
    For c As Integer = 0 To dt.Cols.Count -1
        Sheet(r +1, c).Value = dt.rows(r)(c)
    Next
    'If dt.rows(r)("折扣") >= 0.15 Then '如果折扣大于等于0.15
    'Sheet(r + 1,dt.Cols("折扣").Index).Style = Style '设置折扣单元格的样式
    'End  If
Next
Dim St2 As XLS.Style = Book.NewStyle
Dim St3 As XLS.Style = Book.NewStyle
St2.Format = "yyyy-MM-dd"
St3.Format = "yyyy-MM-dd hh:mm:ss"
Sheet.Cols(dt.Cols("出厂日期").Index).Style = st2
Sheet.Cols(dt.Cols("安装日期").Index).Style = st2
Sheet.Cols(dt.Cols("进厂日期").Index).Style = st2
Sheet.Cols(dt.Cols("填报时间").Index).Style = st3
'打开工作簿
Book.Save(ProjectPath & "reports\" & str)
Dim Proc As New Process
Proc.File = ProjectPath & "reports\" & str
Proc.Start()

这段代码导出了所有列

如何只导出可见列