主题：[求助]Excel报表预览，代码哪里有问题

Dim Book As New XLS.Book(ProjectPath & "Attachments\告知书.xls")
Dim fl As String = ProjectPath & "Reports\告知书.xls"
Book.Build() '生成细节区
Book.Save(fl) '保存工作簿

Dim App As New MSExcel.Application
Dim Wb As MSExcel.WorkBook = App.WorkBooks.Open("d:\test.xls")
Dim Ws As MSExcel.WorkSheet = Wb.WorkSheets(1)
App.Visible = True
Ws.PrintPreview
App.Quit