ActiveWorkbook Returning NULL Error

[thomson02]

Hi,

Hopefully somebody will be able to help me. I'm developing an excel addin using Visual Studio 2008. At the moment i'm trying to display a popup showing the value contained in cell A1. However, i'm getting a runtime error saying that xlWorkBook is null. I've been able to get this to work if i open a workbook but i want to be able to execute my code on the currently active workbook. I thought that ActiveWorkbook (also tried ThisWorkbook) would let me do this but i'm having no success.

The code i'm using is below. I hope somebody will be able to point me in the right direction.

Thanks,
Andrew.

using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
...
...
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;

xlApp = new Excel.ApplicationClass();
xlWorkBook = (Excel.Workbook) xlApp.ActiveWorkbook;
xlWorkSheet = (Excel.Worksheet) xlWorkBook.Worksheets.get_Item(1);

MessageBox.Show(xlWorkSheet.get_Range("A1", "A1").Value2.ToString());

 

[Mike_R]

No problem, Andrew, it looks like you're good to go.

- Mike