ArgumentNullException

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   I am using the QuickPdf .net DLL and I'm getting exceptions from the DLL class constructor of the provided import header file. Snippet of stack trace below,

System.ArgumentNullException: Value cannot be null.  Parameter name: ptr     at System.Runtime.InteropServices.Marshal.GetDelegateForFunctionPointer(IntPtr ptr, Type t)     at External.QuickPDF.DLL..ctor(String dllFileName) in C:\.....\QuickPDF.cs:line 34     at External.QuickPDF.PDFLibrary..ctor(String dllFileName) in C:\.....\QuickPDF.cs:line 2187

I'm using the 32 bit dll (QuickPDFDLL0726.dll) and Ive compiled my project for Any CPU so I dont think its an architecture mismatch.

My application is a .net website running in IIS. I have granted the App Pool user full control to the dll, but Im still getting the problem.
Any ideas?

Cheers
Shaun

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pearlshaun Members Profile Find Members Posts Beginner Joined: 28 Jul 14 Status: Offline Points: 3	Post Options Post Reply Quote pearlshaun Report Post Thanks(0) Quote Reply Topic: ArgumentNullException Posted: 28 Jul 14 at 12:57PM
	I am using the QuickPdf .net DLL and I'm getting exceptions from the DLL class constructor of the provided import header file. Snippet of stack trace below, System.ArgumentNullException: Value cannot be null. Parameter name: ptr at System.Runtime.InteropServices.Marshal.GetDelegateForFunctionPointer(IntPtr ptr, Type t) at External.QuickPDF.DLL..ctor(String dllFileName) in C:\.....\QuickPDF.cs:line 34 at External.QuickPDF.PDFLibrary..ctor(String dllFileName) in C:\.....\QuickPDF.cs:line 2187 I'm using the 32 bit dll (QuickPDFDLL0726.dll) and Ive compiled my project for Any CPU so I dont think its an architecture mismatch. My application is a .net website running in IIS. I have granted the App Pool user full control to the dll, but Im still getting the problem. Any ideas? Cheers Shaun

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3524	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 28 Jul 14 at 1:38PM
	Hi Shaun, compiling with Option "any" means regarding the actual Environment - so 64 bit. 64 bit won't work with 32-bit-dll. You compiling option should be "x86" or similar. But this won't be all ... there will be further Problems i fear. Sorry. Cheers and welcome here, Ingo
	Cheers, Ingo

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 28 Jul 14 at 2:54PM
	Yes. The project needs to be set to x86 and not to AnyCPU. You can use the following code with AnyCPU. if (IntPtr.Size == 4) dllName = "DebenuPDFLibraryDLL1016.DLL"; // 32 bits else dllName = "DebenuPDFLibrary64DLL1016.DLL"; // 64 bits By the way the DLL is not a native .NET DLL. It is a standard Windows DLL. Andrew. Edited by AndrewC - 28 Jul 14 at 3:03PM

pearlshaun Members Profile Find Members Posts Beginner Joined: 28 Jul 14 Status: Offline Points: 3	Post Options Post Reply Quote pearlshaun Report Post Thanks(0) Quote Reply Posted: 28 Jul 14 at 3:35PM
	Thanks for the fast responses chaps. It turned out that you can build for Any CPU in this case, as IIS allows you to specify an app pool to run in WOW64, which I have only just discovered. This has resolved the issue. Thanks for the tips though it steered me in the right direction tips hat