从c＃中SetdllDirectory中指定的路径加载dll

Question

I am new in dotnet.I have a dotnet dll that loads a c dll by using DllImport . I want to place all the dlls in a folder which is diffrent from the location of application. I dont want to modify environmental variables. So i used setdlldirectory API and load my c# assembly through Assembly.Loadfrom(..) . I checked that SetdllDirectory is working fine by verifying the value of GetDllDirectory(..) . But it is neither loading C# dll nor c dll from that folder. I am able to load C# dll by specyfing the path in Assembly.Loadfrom . But not able to load c dll.

Thanks in advance!!

Answer 1

I'd suggest adding the directory path to PATH env variable in runtime, using the following code:

var dllDirectory = @"C:/some/path";
Environment.SetEnvironmentVariable("PATH", Environment.GetEnvironmentVariable("PATH") + ";" + dllDirectory);

That way, the change is only affecting the running process and is discarded when it exits.

Answer 2

Take a look at the documentation for LoadFrom and you'll find that it says: If a native image exists for assemblyFile, it is not used. The assembly cannot be loaded as domain neutral.

I believe you're going to need to add the DLL directory to the EXE's path.