主题：ShowAppWindow关闭文件未执行，是什么原因啊？

If FileIsOpened(ProjectPath & "Reports\明细.pdf")= True Then
     ShowAppWindow(ProjectPath & "Reports\明细.pdf",5)
End  If

Dim Book As New XLS.Book(ProjectPath & "Attachments\明细.xls") '打开模板
Dim fl As String = ProjectPath & "Reports\明细.pdf"
Dim Sheet As XLS.Sheet = Book.Sheets(0)

Book.Build() '生成报表
Book.SaveToPDF(fl) '保存为PDF文件
Dim Proc As New Process '打开PDF文件
Proc.File = fl
Proc.Start()

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