Question

I am programatically opening excel workbooks under a folder tree to check for some project references using the following code –

workbook = app.Workbooks.Open(fileName,false,true,Missing,Missing,.....);
foreach(Reference r in workbook.VBProject.References)
{
      //check for a specific reference here
}

This works fine but my folder structure is very deep and I have over 20,000 spreadsheets stored in them. Sometimes depending on the size of the excel file, the call to Workbooks.Open() takes a long time (over 5 minutes per call on some files). Is there a faster more efficient way to do this?

Thanks for the help

Answer 1

I don’t think you can increase the Workbooks.Open performance. However if your main intention is just to check if a particular reference is used by the Spreadsheet or not, then consider opening the Excel file in binary mode and searching for the dll string.(The path of the dll providing the functionality, which can be seen in the Location part of the References Window).

This would be very crude way, but if the Workbook.Open performance is really a bottleneck then you can definitely give it a try.