How to Get the Location of the Dll Currently Executing

How to get the location of the DLL currently executing?

You are looking for System.Reflection.Assembly.GetExecutingAssembly()

string assemblyFolder = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
string xmlFileName = Path.Combine(assemblyFolder,"AggregatorItems.xml");

Note:

The .Location property returns the location of the currently running DLL file.

Under some conditions the DLL is shadow copied before execution, and the .Location property will return the path of the copy. If you want the path of the original DLL, use the Assembly.GetExecutingAssembly().CodeBase property instead.

.CodeBase contains a prefix (file:\), which you may need to remove.

Get DLL path at runtime

You can use the GetModuleHandleEx function and get the handle to a static function in your DLL. You'll find more information here.

After that you can use GetModuleFileName to get the path from the handle you just obtained. More information on that call is here.

A complete example:

char path[MAX_PATH];
HMODULE hm = NULL;

if (GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | 
        GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
        (LPCSTR) &functionInThisDll, &hm) == 0)
{
    int ret = GetLastError();
    fprintf(stderr, "GetModuleHandle failed, error = %d\n", ret);
    // Return or however you want to handle an error.
}
if (GetModuleFileName(hm, path, sizeof(path)) == 0)
{
    int ret = GetLastError();
    fprintf(stderr, "GetModuleFileName failed, error = %d\n", ret);
    // Return or however you want to handle an error.
}

// The path variable should now contain the full filepath for this DLL.

Get Absolute Path Relative to DLL location

GetFullPath always assumes relative to the current directory unless you specify an absolute path. You should just manually combine your assembly path with your relative path. You can then normalize the result to get a clean path.

string assemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
string filePathRelativeToAssembly = Path.Combine(assemblyPath, @"..\SomeFolder\SomeRelativeFile.txt");
string normalizedPath = Path.GetFullPath(filePathRelativeToAssembly);

For example. If the assembly location is "C:\Test\MyAssembly.dll" then you get this

assemblyPath = "C:\Test"
filePathRelativeToAssembly = "C:\Test\..\SomeFolder\SomeRelativeFile.txt"
normalizedPath = "C:\Test\SomeFolder\SomeRelativeFile.txt"

Also, if you passed in an absolute path as the second part of Path.Combine it will still do the proper thing.

string assemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
string filePathRelativeToAssembly = Path.Combine(assemblyPath, @"C:\AbsoluteFile.txt");
string normalizedPath = Path.GetFullPath(filePathRelativeToAssembly);

will give you

filePathRelativeToAssembly = "C:\AbsoluteFile.txt"
normalizedPath = "C:\AbsoluteFile.txt"

How do I get the path of the assembly the code is in?

Note: Assembly.CodeBase is deprecated in .NET Core/.NET 5+: https://learn.microsoft.com/en-us/dotnet/api/system.reflection.assembly.codebase?view=net-5.0

Original answer:

I've defined the following property as we use this often in unit testing.

public static string AssemblyDirectory
{
    get
    {
        string codeBase = Assembly.GetExecutingAssembly().CodeBase;
        UriBuilder uri = new UriBuilder(codeBase);
        string path = Uri.UnescapeDataString(uri.Path);
        return Path.GetDirectoryName(path);
    }
}

The Assembly.Location property sometimes gives you some funny results when using NUnit (where assemblies run from a temporary folder), so I prefer to use CodeBase which gives you the path in URI format, then UriBuild.UnescapeDataString removes the File:// at the beginning, and GetDirectoryName changes it to the normal windows format.

Get actual dll path in .Net

You can use:

Assembly.GetExecutingAssembly().Location

which will give you the path of the executing assembly then use:

System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)

which will give the containing folder.

Getting the path of the current assembly

You can use:

string path = (new System.Uri(Assembly.GetExecutingAssembly().CodeBase)).AbsolutePath;

Some suggestions in the comments are to pass that through System.Uri.UnescapeDataString (from vvnurmi) to ensure that any percent-encoding is handled, and to use Path.GetFullpath (from TrueWill) to ensure that the path is in standard Windows form (rather than having slashes instead of backslashes). Here's an example of what you get at each stage:

string s = Assembly.GetExecutingAssembly().CodeBase;
Console.WriteLine("CodeBase: [" + s + "]");
s = (new Uri(s)).AbsolutePath;
Console.WriteLine("AbsolutePath: [" + s + "]");
s = Uri.UnescapeDataString(s);
Console.WriteLine("Unescaped: [" + s + "]");
s = Path.GetFullPath(s);
Console.WriteLine("FullPath: [" + s + "]");

Output if we're running C:\Temp\Temp App\bin\Debug\TempApp.EXE:

CodeBase: [file:///C:/Temp/Temp App/bin/Debug/TempApp.EXE]
AbsolutePath: [C:/Temp/Temp%20App/bin/Debug/TempApp.EXE]
Unescaped: [C:/Temp/Temp App/bin/Debug/TempApp.EXE]
FullPath: [C:\Temp\Temp App\bin\Debug\TempApp.EXE]

C# How to get current directory path

I will answer my own question, It's not possible to get current path from library project. You'll have to get it from installer. There is no other way.

Thank you.

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