All the examples I've seen set pxoPageList to IntPtr.Zero which processes all pages. I need to examine the OCR results of a PDF one page at a time. I've tried a few ways of setting pxoPageList (such as pxoPagelist = Marshal.AllocHGlobal(Len(intPageNumber.ToString)) and pxoPagelist = Marshal.StringToHGlobalAnsi(intPageNumber.ToString) ) but I can't get any to work. When I use IntPtr.Zero, the OCR_GetText function works great. Any other setting causes an Access Violation. Would you be kind enough to share some sample VB.Net code that shows how pxoPageList should be set to process a particular page of a PDF?