Question

I’m converting a VB6 application into VB.Net and having trouble with the basics. I start off with:-

Dim xl As Excel.Application
Dim xlsheet As Excel.Worksheet
Dim xlwbook As Excel.Workbook

xl = New Excel.Application
xlwbook = xl.Workbooks.Open(my_data.file_name)
xlsheet = xlwbook.Sheets(1)

but the last line doesn’t compile; it reports

Option Strict On disallows implicit conversion from ‘Object’ to ‘Microsoft.Office.Interop.Excel.Worksheet’

I can make this go away by replacing the line with

xlsheet = CType(xlwbook.Sheets(1), Excel.Worksheet)

but that does’t look like the right thing to do to me. If the assignment is correct, I would have thought the object should naturally have the correct type.

So: does anyone know what the correct thing I should be doing here?

Answer 1

It is not possible without a conversion of type (If Option Strict Is On) because .NET cannot understand a VBA Collection.

I believe this bug report is related to the issue:

If you have a look at the Excel Example on this page (Converting Code from VBA to Visual Basic .NET), then it shows this code:

Dim ThisWorksheet As Excel.Worksheet = _
        CType(ThisWorkbook.Worksheets.Item("Sheet1"), Excel.Worksheet)

There have been several post about this issue like here and here but there doesn’t seem to be a better way round it.