The Excel instance opened through automation shouldn't be visible. Make sure
you don't have any line like this in your code:

m_exlApp.Visible = True

If you need the Excel instance to be visible, you can set the Interactive
property to false.

m_exlApp.Interactive=False




"How to reject user operation" wrote:

Hello everyone
I am working on a program about searching data from all the .xls files, But
when I let my program run (user cannot see this program, because this program
is run as a windows service), if the user open a .xls file, it seems
myprogram and the file user opened will share a same Excel application--and
the result is when user look at his file, he can also see the file open and
close by my program
How can I reject the operation from users?

I tried 2 ways, but same result
Here is the key part in my program(vb 2005):
Private m_exlApp As Excel.Application ' Excel Application
.....
' for every filepath
Dim excelBook As Excel.Workbook
Dim sheet As Excel.Worksheet

m_exlApp.Workbooks.Open(filepath, ReadOnly:=True)
excelBook = m_exlApp.ActiveWorkbook

For Each sheet In excelBook.Sheets
' do something
Next

excelBook.Close()
......
m_exlApp.Quit()