主题：调出EXCL

方法一：可以用goto

msgbox(1)
label1:
Dim dlg As New OpenFileDialog '定义一个新的OpenFileDialog
dlg.Filter= "Excel文件|*.xls;*.xlsx" '设置筛选器
If dlg.ShowDialog = DialogResult.Ok Then '如果用户单击了确定按钮
    If Date.Now.Second Mod 3 <> 0 Then '不是3的倍数,就循环
        goto label1
    End If
End If

msgbox(2)

方法二：可以用循环，满足条件，就退出

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循环excel的每一行判断，类似代码

Dim dlg As New OpenFileDialog '定义一个新的OpenFileDialog
dlg.Filter= "Excel文件|*.xls;*.xlsx" '设置筛选器
If dlg.ShowDialog = DialogResult.Ok Then '如果用户单击了确定按钮
    Dim book As new XLS.Book(dlg.FileName)
    Dim sheet As XLS.Sheet = book.Sheets(0)
    Dim ls As new List(of String)
    Dim style As XLS.style = book.NewStyle
    style.BackColor = color.red
    For i As Integer = 0 To sheet.rows.count-1
        Dim bj As String = sheet(i,0).text
        Dim xm As String = sheet(i,1).text
        If ls.Contains(bj & "|" & xm) = False Then
            ls.add(bj & "|" & xm)
        Else
            sheet(i,0).Style = style
            sheet(i,1).Style = style
        End If
    Next
    book.save(dlg.FileName)
    Dim proc As new Process
    proc.File = dlg.FileName
    proc.Start
End If