从相对路径加载c＃中的dll

Question

I am loading a dll at runtime like this:

var DLL = Assembly.LoadFile(@"..\..\BuildDLLs\myDLL.dll");

I am getting an ArgumentException that is asking for an absolute path.

I don't want to use an absolute path, I want to use a relative path.

How can I do that?

Answer 1

Simple. Make an extra step:

var dllFile = new FileInfo(@"..\..\BuildDLLs\myDLL.dll");
var DLL = Assembly.LoadFile(dllFile.FullName);

Answer 2

I'm not aware of a way to use a relative path so someone else might have an answer for that. However you could just build an absolute path from relative paths and use that.

// Gets the folder path in which your .exe is located
var parentFolder = Path.GetDirectoryName(System.Reflection.Assembly.GetEntryAssembly().Location);

// Makes the absolute path
var absolutePath = Path.Combine(parentFolder, "\BuildDLLs\myDLL.dll");

// Load the DLL using the absolute path
var DLL = Assembly.LoadFile(absolutePath);

Now if your program is ever moved it'll still work.

Answer 3

I also do not know a way to use a relative path to load a library at runtime but if the path is just relative to your project location on the disc of the user but has a fixed location in relation to your project you could use something like this:

System.Reflection.Assembly.GetEntryAssembly().Location;
//to get the path of your main applications .exe

and

Directory.GetParent(String)
//to move your way upwards in your folder sturcture

then

Path.Combine(String, String)
/*to combine the path you just navigated to inside your project with the knowledge of where you can find your .dll inside of your folder sturcture and combine them into one path again.*/

Maybe this helps you to solve your problem, I also used this "dirty" method to load some .dlls at runtime.This just works if you have a fixed folder sturcture of course.