标题：Excel 报表的日期格式化代码问题

当报表模板中的日期列没有设置日期格式的时候：这段格式化日期的代码怎么不起作用？？？

Dim Book1 As New XLS.Book(ProjectPath & "Attachments\订单.xls")
Dim Sheet As XLS.Sheet = Book1.Sheets(0)

Dim St2 As XLS.Style = Book1.NewStyle()      ‘这段格式化日期的代码怎么不起作用？？？
St2.Format = "yyyy-MM-dd"
Sheet.Cols(tables("订单").Cols("日期").index).Style = st2

Book1.Build() '生成细节区
Book1.Save(ProjectPath & "reports\订单.xls")
Dim Proc As New Process '打开工作簿
Proc.File = ProjectPath & "reports\订单.xls" 
Proc.Start()

Dim Book1 As New XLS.Book(ProjectPath & "Attachments\订单.xls")
Dim Sheet As XLS.Sheet = Book1.Sheets(0)
Dim St2 As XLS.Style = Book1.NewStyle()
St2.BorderTop = XLS.LineStyleEnum.Thin
St2.BorderBottom = XLS.LineStyleEnum.Thin
St2.BorderLeft = XLS.LineStyleEnum.Thin
St2.BorderRight = XLS.LineStyleEnum.Thin
St2.Format = "yyyy-MM-dd"
For r As Integer = 2 to 3
    Sheet(r,tables("订单").cols.Count).Style = St2
 Next
Book1.Build() '生成细节区
Book1.Save(ProjectPath & "reports\订单.xls")
Dim Proc As New Process '打开工作簿
Proc.File = ProjectPath & "reports\订单.xls" 
Proc.Start()

这样也行

Dim Book1 As New XLS.Book(ProjectPath & "Attachments\订单.xls")
Dim Sheet As XLS.Sheet = Book1.Sheets(0)

Dim St2 As XLS.Style = Book1.NewStyle()      '这段格式化日期的代码怎么不起作用???
St2.BorderTop = XLS.LineStyleEnum.Thin
St2.BorderBottom = XLS.LineStyleEnum.Thin
St2.BorderLeft = XLS.LineStyleEnum.Thin
St2.BorderRight = XLS.LineStyleEnum.Thin
St2.Format = "yyyy-MM-dd"
Sheet(3,tables("订单").cols.Count).Style = St2
Book1.Build() '生成细节区
Book1.Save(ProjectPath & "reports\订单.xls")
Dim Proc As New Process '打开工作簿
Proc.File = ProjectPath & "reports\订单.xls" 
Proc.Start()

谢谢yang版～～～

原来
Sheet.Cols(tables("订单").Cols("日期").index).Style = st2      改为：
Sheet(3,tables("订单").cols.Count).Style = St2                    就可以了。   呵呵～

光这样改还不够,新的样式会删除原有的样式,所以还得重新设置边框