VB.Net 互操作 Excel Com 异常

Question

到目前为止，这段代码已经完美运行了一段时间，

它抛出异常：

System.InvalidCastException：无法转换类型的 COM 对象 'System.__ComObject' 到类类型 'Microsoft.Office.Interop.Excel.WorksheetClass'

Dim ds_allJobs As DataSet = DBHandling.searchJob("", "", "all open jobs")
Dim xlApp = New Microsoft.Office.Interop.Excel.Application

xlApp.Visible = False
xlApp.ScreenUpdating = False

Dim xlWorkbook = xlApp.Workbooks.Add(XlWBATemplate.xlWBATWorksheet)
Dim xlWorksheet = New Microsoft.Office.Interop.Excel.Worksheet

xlWorksheet = xlWorkbook.ActiveSheet 'IT FAILS HERE
xlWorksheet.Name = "Open Jobs"    

有什么建议吗？

Answer 1

最好指定对象的类型（例如exWorkbook As Excel.Workbook）

这是制作新工作表的一种方法：

'create a new excel application (window)
Dim exApp As New Excel.Application
'add a workbook to it, and take a look at the first worksheet
Dim exWorkbook As Excel.Workbook = exApp.Application.Workbooks.Add()
'create a new worksheet
Dim exWorksheet As Excel.Worksheet
'add this worksheet to the current applicatoin
exWorksheet = CType(exApp.Worksheets.Add(), Excel.Worksheet)

这是否回答了您的问题？最后一行是将对象转换为类型工作表。