Calling LoadLibrary using pinvoke from UWP C# application

Question

I'm trying to call methods from an unmanaged dll from a C# UWP application. I do this, but pinvoking "LoadLibrary()" on the unmanaged dll so that I can use it.

This all works fine in Debug mode, however in Release mode, I get a curious error:

Message: Class Initialization method Tests.UnitTests.InitializeClient threw exception. System.TypeLoadException: System.TypeLoadException: Unresolved P/Invoke method 'LoadLibrary!kernel32' in assembly 'Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' because it is not available in UWP applications. Please either use an another API , or use [DllImport(ExactSpelling=true) to indicate that you understand the implications of using non-UWP application APIs..

Here is my method to pinvoke Load Library:

    [DllImport("kernel32", CharSet = CharSet.Unicode, SetLastError = true)]
    public static extern IntPtr LoadLibrary(string librayName);

Unfortunately, if I add the "ExactSpelling = true" as below:

    [DllImport("kernel32", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
    public static extern IntPtr LoadLibrary(string librayName);

Then calling it throws an exception:

System.EntryPointNotFoundException: 'Unable to find an entry point named 'LoadLibrary' in DLL 'kernel32'.'

Any help is much appreciated!

Salomon

Indeed, there is no entry point named LoadLibrary in kernel32.dll. There are two others: LoadLibraryA for ANSI strings and LoadLibraryW for Unicode strings. You want the latter. No guarantee it works then, though. From what I gather you're supposed to use LoadPackagedLibrary on UWP (but I'm not a UWP developer). – Vigil

LoadLibraryW() is verboten in a UWP app. You cannot get your app certified and can't sell and deploy through the store. – Katherinkatherina

You sure about that? I was able to get LoadLibraryW loaded through the [DllImport("API-MS-WIN-CORE-LIBRARYLOADER-L2-1-0.DLL", SetLastError = true)] import. – Salomon

Answer 1

Use LoadPackagedLibrary instead:

[DllImport("API-MS-WIN-CORE-LIBRARYLOADER-L2-1-0.DLL", SetLastError = true)]
public static extern IntPtr LoadPackagedLibrary([MarshalAs(UnmanagedType.LPWStr)]string libraryName, int reserved = 0);

Bovine

Sorry, I made a typo. Fixed now. – Bovine