Open File Dialog, One Filter for Multiple Excel Extensions?
If you want to merge the filters (eg. CSV and Excel files), use this formula:
OpenFileDialog of = new OpenFileDialog();
of.Filter = "CSV files (*.csv)|*.csv|Excel Files|*.xls;*.xlsx";
Or if you want to see XML or PDF files in one time use this:
of.Filter = @" XML or PDF |*.xml;*.pdf";
Use a semicolon
OpenFileDialog of = new OpenFileDialog();
of.Filter = "Excel Files|*.xls;*.xlsx;*.xlsm";