ChatGPT解决这个技术问题 Extra ChatGPT

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

Is there a way to get the path for the assembly in which the current code resides? I do not want the path of the calling assembly, just the one containing the code.

Basically my unit test needs to read some xml test files which are located relative to the dll. I want the path to always resolve correctly regardless of whether the testing dll is run from TestDriven.NET, the MbUnit GUI or something else.

Edit: People seem to be misunderstanding what I'm asking.

My test library is located in say

C:\projects\myapplication\daotests\bin\Debug\daotests.dll

and I would like to get this path:

C:\projects\myapplication\daotests\bin\Debug\

The three suggestions so far fail me when I run from the MbUnit Gui:

Environment.CurrentDirectory gives c:\Program Files\MbUnit

System.Reflection.Assembly.GetAssembly(typeof(DaoTests)).Location gives C:\Documents and Settings\george\Local Settings\Temp\ ....\DaoTests.dll

System.Reflection.Assembly.GetExecutingAssembly().Location gives the same as the previous.

This is your solution: var dir = AppDomain.CurrentDomain.BaseDirectory;
This should be the accepted solution. AppDomain.CurrentDomain.BaseDirectory is the correct approach.
I came here looking for a solution for a nuget package to read a JSON file from its pacakge directory. Seems that when a nuget package is executed the "AppDomain.CurrentDomain.BaseDirectory" points to the running projects directory, and not the nuget package directory. None of these seem to target the nuget package directory correctly.
@Lucas no it wouldn't because that's not what this question was about (in fact when it was asked, nuget didn't exist) - feel free to start a new question and ping me in there but I can tell you right now that its impossible in most cases. For most projects the nuget directory is packages next to the sln file. BUT when you compile and distribute things there is no sln file and no packages directory. During compilation, things that are needed (but not everything) is copied into the bin directory. Your best bet is to use a postbuild script to copy the file you want.

M
Mikael Engver

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.


This has one issue I came across, if your directory name is: c:\My%20Directory then the Uri.UnescapeDataString will return: c:\My Directory This means that File.Exists("c:\My Directory\MyFile.txt") will return false as the correct path is actually "c:\My%20Directory\MyFile.txt" I came across this as our SVN paths have spaces in them and when we check them out it encodes the spaces.
Be careful when you use this to check File.Exist() as this method will return false on UNC path. Use @Keith's answer instead.
Did not know you could put static before public. Nice to know and i think i prefer for readability
Note: this does not work with network locations (e.g. \\REMOT_EPC\Folder)
Also this will not work if the directory has number signs '#' in it. Number signs are allowed in directory and file names in Windows.
K
Keith

Does this help?

//get the full location of the assembly with DaoTests in it
string fullPath = System.Reflection.Assembly.GetAssembly(typeof(DaoTests)).Location;

//get the folder that's in
string theDirectory = Path.GetDirectoryName( fullPath );

Set the xml files to be content, copied with the dll, or resources, read from the dll.
Or just typeof(DaoTests).Assembly
I'd personally go with a method like this: public static string GetAssemblyDirectory<T>(){return System.IO.Path.GetDirectoryName(typeof(T).Assembly.Location);}
@SLaks @JohnySkovdal @Keith : Hey guys, use Assembly.GetExecutingAssembly(). It "gets the assembly that contains the code that is currently executing" (from method description). I use this in my AddIn "EntitiesToDTOs". See AssemblyHelper.cs for real example.
Had a problem with the post by @John Silby, as it doesnt look like it works for UNC paths... e.g. \\Server\Folder\File.ext. This one did the trick. +1
T
Tim Cooper

It's as simple as this:

var dir = AppDomain.CurrentDomain.BaseDirectory;

This should be the accepted solution. AppDomain.CurrentDomain.BaseDirectory is the correct approach.
thanks for bringing my attention back to this - not sure if that was available at the time I asked the question but it is now.
No, this is wrong. This returns the path of the ORIGINAL ENTRY POINT not the currently executing code. If you have loaded an assembly manually from a different path, or if it has been loaded from GAC, it will return the wrong result. This answer is correct: stackoverflow.com/a/283917/243557 Quicker still is Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location).
Actually this won't work in web applications but as far as I have found the following augmentation should work for any type of application: AppDomain.CurrentDomain.RelativeSearchPath ?? AppDomain.CurrentDomain.BaseDirectory
This is excellent for unit testing if you just want to get the original bin path of your test assembly (say, to reach auxilary data files in subfolders). The test assembly is the entry point of your code.
P
Phil

Same as John's answer, but a slightly less verbose extension method.

public static string GetDirectoryPath(this Assembly assembly)
{
    string filePath = new Uri(assembly.CodeBase).LocalPath;
    return Path.GetDirectoryName(filePath);            
}

Now you can do:

var localDir = Assembly.GetExecutingAssembly().GetDirectoryPath();

or if you prefer:

var localDir = typeof(DaoTests).Assembly.GetDirectoryPath();

Did you meant assembly instead of Assembly.GetExecutingAssembly() ?
As Dude points out, you passed in an argument and failed to use it.
This answer is just plain wrong for the question at hand. A modified version of this answer could give you the path of a given assembly. However, here, we're specifically looking for the executing assembly, and so passing in an assembly makes no sense. An extension method is the wrong tool for the job.
How do you get the location without the trailing bin/Debug/netcoreapp etc?
This solves the problem when called like Assembly.GetExecutingAssembly().GetDirectoryPath(). And new Uri is cleaner than using UriBuilder and UnescapeDataString in John Sibly's answer.
S
Stefan Laity

The only solution that worked for me when using CodeBase and UNC Network shares was:

System.IO.Path.GetDirectoryName(new System.Uri(System.Reflection.Assembly.GetExecutingAssembly().CodeBase).LocalPath);

It also works with normal URIs too.


This should be the accepted answer. It's really annoying that the default codebase doesn't handle UNC shares correct.
This comes crashing down when the folder contains spaces and god knows what other characters...
I've been using this a lot and have found one scenario where it fails: if this line of code itself is part of a NuGet package which is then used by an application! We can support that scenario too by replacing GetExecutingAssembly() by GetCallingAssembly().
@Timo: have you verified if this change has side effects? If so please edit the answer to include the fix.
@IgnacioSolerGarcia Sadly I must report that it only worked one layer deep, i.e. it fails if the NuGet package was called by another NuGet package! I am now using this (from a comment on this page by Chernomordik): AppDomain.CurrentDomain.RelativeSearchPath ?? AppDomain.CurrentDomain.BaseDirectory. The first part is for web applications, and the second for other applications.
P
Pierre Arnaud

This should work, unless the assembly is shadow copied:

string path = System.Reflection.Assembly.GetExecutingAssembly().Location

I
Ilya Chernomordik

I believe this would work for any kind of application:

AppDomain.CurrentDomain.RelativeSearchPath ?? AppDomain.CurrentDomain.BaseDirectory

My experiments show this to be the most foolproof answer, covering not only web and console applications, but also calls from unit tests and NuGet packages (nested to any level of recursion).
Thanks for this elegant solution!
h
huseyint

What about this:

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

Does not work with .net 5 bundled assemblies , see stackoverflow.com/a/62626131/2663813
b
bluish
AppDomain.CurrentDomain.BaseDirectory

works with MbUnit GUI.


This worked great for writing a file relative to the root directory in an asp.net web app
I have found that this one works best generally. Pick it if you are unsure.
this is the only correct answers, all the other answers are deprecated and do not work when assemblies are merged as the location will be empty
C
Curt Hagenlocher

I suspect that the real issue here is that your test runner is copying your assembly to a different location. There's no way at runtime to tell where the assembly was copied from, but you can probably flip a switch to tell the test runner to run the assembly from where it is and not to copy it to a shadow directory.

Such a switch is likely to be different for each test runner, of course.

Have you considered embedding your XML data as resources inside your test assembly?


+1 for pointing out the issue with shadow copying. However, it is indeed possible to determine the original place from the Assembly.CodeBase.
c
cube45

Starting with .net framework 4.6 / .net core 1.0, there is now a AppContext.BaseDirectory, which should give the same result as AppDomain.CurrentDomain.BaseDirectory, except that AppDomains were not part of the .net core 1.x /.net standard 1.x API.

AppContext.BaseDirectory

EDIT: The documentation now even state:

In .NET 5.0 and later versions, for bundled assemblies, the value returned is the containing directory of the host executable.

Indeed, Assembly.Location doc doc says :

In .NET 5.0 and later versions, for bundled assemblies, the value returned is an empty string.


D
David C Fuchs

How about this ...

string ThisdllDirectory = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);

Then just hack off what you do not need


T
Thomas Weller

tl;dr

The concept of an assembly and a DLL file are not the same. Depending on how the assembly was loaded the path information gets lost or is not available at all. Most of the time the provided answers will work, though.

There is one misconception the question and the previous answers have. In most of the cases the provided answers will work just fine but there are cases where it is not possible to get the correct path of the assembly which the current code resides.

The concept of an assembly - which contains executable code - and a dll file - which contains the assembly - are not tightly coupled. An assembly may come from a DLL file but it does not have to.

Using the Assembly.Load(Byte[]) (MSDN) method you can load an assembly directly from a byte array in memory. It does not matter where the byte array comes from. It could be loaded from a file, downloaded from the internet, dynamically generated,...

Here is an example which loads an assembly from a byte array. The path information gets lost after the file was loaded. It is not possible to get the original file path and all previous described methods do not work.

This method is located in the executing assembly which is located at "D:/Software/DynamicAssemblyLoad/DynamicAssemblyLoad/bin/Debug/Runner.exe"

static void Main(string[] args)
{
    var fileContent = File.ReadAllBytes(@"C:\Library.dll");

    var assembly = Assembly.Load(fileContent);

    // Call the method of the library using reflection
    assembly
        ?.GetType("Library.LibraryClass")
        ?.GetMethod("PrintPath", BindingFlags.Public | BindingFlags.Static)
        ?.Invoke(null, null);

    Console.WriteLine("Hello from Application:");
    Console.WriteLine($"GetViaAssemblyCodeBase: {GetViaAssemblyCodeBase(assembly)}");
    Console.WriteLine($"GetViaAssemblyLocation: {assembly.Location}");
    Console.WriteLine($"GetViaAppDomain       : {AppDomain.CurrentDomain.BaseDirectory}");

    Console.ReadLine();
}

This class is located in the Library.dll:

public class LibraryClass
{
    public static void PrintPath()
    {
        var assembly = Assembly.GetAssembly(typeof(LibraryClass));
        Console.WriteLine("Hello from Library:");
        Console.WriteLine($"GetViaAssemblyCodeBase: {GetViaAssemblyCodeBase(assembly)}");
        Console.WriteLine($"GetViaAssemblyLocation: {assembly.Location}");
        Console.WriteLine($"GetViaAppDomain       : {AppDomain.CurrentDomain.BaseDirectory}");
    }
}

For the sake of completeness here is the implementations of GetViaAssemblyCodeBase() which is the same for both assemblies:

private static string GetViaAssemblyCodeBase(Assembly assembly)
{
    var codeBase = assembly.CodeBase;
    var uri = new UriBuilder(codeBase);
    return Uri.UnescapeDataString(uri.Path);
}

The Runner prints the following output:

Hello from Library:
GetViaAssemblyCodeBase: D:/Software/DynamicAssemblyLoad/DynamicAssemblyLoad/bin/Debug/Runner.exe
GetViaAssemblyLocation:
GetViaAppDomain       : D:\Software\DynamicAssemblyLoad\DynamicAssemblyLoad\bin\Debug\
Hello from Application:
GetViaAssemblyCodeBase: D:/Software/DynamicAssemblyLoad/DynamicAssemblyLoad/bin/Debug/Runner.exe
GetViaAssemblyLocation:
GetViaAppDomain       : D:\Software\DynamicAssemblyLoad\DynamicAssemblyLoad\bin\Debug\

As you can see, neither the code base, location or base directory are correct.


C
Community

As far as I can tell, most of the other answers have a few problems.

The correct way to do this for a disk-based (as opposed to web-based), non-GACed assembly is to use the currently executing assembly's CodeBase property.

This returns a URL (file://). Instead of messing around with string manipulation or UnescapeDataString, this can be converted with minimal fuss by leveraging the LocalPath property of Uri.

var codeBaseUrl = Assembly.GetExecutingAssembly().CodeBase;
var filePathToCodeBase = new Uri(codeBaseUrl).LocalPath;
var directoryPath = Path.GetDirectoryName(filePathToCodeBase);

Does not work if path contains # (EscapedCodeBase works, but EscapedCodeBase does not work if the path contains e.g. %20 verbatim (which is an allowed character sequence in a Windows path)
If we want to have this code in a NuGet package, we can fix that scenario by replacing GetExecutingAssembly() by GetCallingAssembly().
P
Pierre Arnaud
var assembly = System.Reflection.Assembly.GetExecutingAssembly();
var assemblyPath = assembly.GetFiles()[0].Name;
var assemblyDir = System.IO.Path.GetDirectoryName(assemblyPath);

P
Peter Mortensen

Here is a VB.NET port of John Sibly's code. Visual Basic is not case sensitive, so a couple of his variable names were colliding with type names.

Public Shared ReadOnly Property AssemblyDirectory() As String
    Get
        Dim codeBase As String = Assembly.GetExecutingAssembly().CodeBase
        Dim uriBuilder As New UriBuilder(codeBase)
        Dim assemblyPath As String = Uri.UnescapeDataString(uriBuilder.Path)
        Return Path.GetDirectoryName(assemblyPath)
    End Get
End Property

G
George Mauer

In all these years, nobody has actually mentioned this one. A trick I learned from the awesome ApprovalTests project. The trick is that you use the debugging information in the assembly to find the original directory.

This will not work in RELEASE mode, nor with optimizations enabled, nor on a machine different from the one it was compiled on.

But this will get you paths that are relative to the location of the source code file you call it from

public static class PathUtilities
{
    public static string GetAdjacentFile(string relativePath)
    {
        return GetDirectoryForCaller(1) + relativePath;
    }
    public static string GetDirectoryForCaller()
    {
        return GetDirectoryForCaller(1);
    }


    public static string GetDirectoryForCaller(int callerStackDepth)
    {
        var stackFrame = new StackTrace(true).GetFrame(callerStackDepth + 1);
        return GetDirectoryForStackFrame(stackFrame);
    }

    public static string GetDirectoryForStackFrame(StackFrame stackFrame)
    {
        return new FileInfo(stackFrame.GetFileName()).Directory.FullName + Path.DirectorySeparatorChar;
    }
}

d
dan gibson

I've been using Assembly.CodeBase instead of Location:

Assembly a;
a = Assembly.GetAssembly(typeof(DaoTests));
string s = a.CodeBase.ToUpper(); // file:///c:/path/name.dll
Assert.AreEqual(true, s.StartsWith("FILE://"), "CodeBase is " + s);
s = s.Substring(7, s.LastIndexOf('/') - 7); // 7 = "file://"
while (s.StartsWith("/")) {
    s = s.Substring(1, s.Length - 1);
}
s = s.Replace("/", "\\");

It's been working, but I'm no longer sure it is 100% correct. The page at http://blogs.msdn.com/suzcook/archive/2003/06/26/assembly-codebase-vs-assembly-location.aspx says:

"The CodeBase is a URL to the place where the file was found, while the Location is the path where it was actually loaded. For example, if the assembly was downloaded from the internet, its CodeBase may start with "http://", but its Location may start with "C:\". If the file was shadow-copied, the Location would be the path to the copy of the file in the shadow copy dir. It’s also good to know that the CodeBase is not guaranteed to be set for assemblies in the GAC. Location will always be set for assemblies loaded from disk, however."

You may want to use CodeBase instead of Location.


@Kiquenet: So much code just for converting an URI into a path. Sure it could be improved. Look at Mike Schall's or SoMoS's answer. You should not try to convert URIs on string level, but instead use the suitable objects. OK, it is also clumsy that Assembly.CodeBase returns a string instead of a more suitable object, like URI or FileInfo.
D
David Basarab

The current directory where you exist.

Environment.CurrentDirectory;  // This is the current directory of your application

If you copy the .xml file out with build you should find it.

or

System.Reflection.Assembly assembly = System.Reflection.Assembly.GetAssembly(typeof(SomeObject));

// The location of the Assembly
assembly.Location;

this will be problematic if the assembly has been shadow copied.
+1520! Environment.CurrentDirectory works if you are using reflection in MSBuild task class, where the executing assembly resides in GAC and your code is somewhere else.
In general CurrentDirectory does not tell you where your executables reside. That's not what it is used for. It just happens to frequently be the same location the executables are in, so a lot of programmers don't understand the difference. Then they end up creating trouble for some of the end users that expected the application to understand proper use of CurrentDirectory.
s
sumitup

You can get the bin path by AppDomain.CurrentDomain.RelativeSearchPath


B
Bryan

All of the proposed answers work when the developer can change the code to include the required snippet, but if you wanted to do this without changing any code you could use Process Explorer.

It will list all executing dlls on the system, you may need to determine the process id of your running application, but that is usually not too difficult.

I've written a full description of how do this for a dll inside II - http://nodogmablog.bryanhogan.net/2016/09/locating-and-checking-an-executing-dll-on-a-running-web-server/


Note that first of all, the code in the article is fairly IIS-centric and second, it gives you (I believe) all currently loaded dlls, not what is running at any one time.
The example given relates to iis, but the same steps apply if the dll is running in a process outside of iis. It's just a matter of identifying the process id. I'll update article to note that. Thanks for the suggestion.
g
gamesguru

in a windows form app, you can simply use Application.StartupPath

but for DLLs and console apps the code is much harder to remember...

string slash = Path.DirectorySeparatorChar.ToString();
string root = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);

root += slash;
string settingsIni = root + "settings.ini"

F
Fedor Shihantsov

You will get incorrect directory if a path contains the '#' symbol. So I use a modification of the John Sibly answer that is combination UriBuilder.Path and UriBuilder.Fragment:

public static string AssemblyDirectory
{
    get
    {
        string codeBase = Assembly.GetExecutingAssembly().CodeBase;
        UriBuilder uri = new UriBuilder(codeBase);
        //modification of the John Sibly answer    
        string path = Uri.UnescapeDataString(uri.Path.Replace("/", "\\") + 
          uri.Fragment.Replace("/", "\\"));
        return Path.GetDirectoryName(path);
     }
}

T
TPG

For ASP.Net, it doesn't work. I found a better covered solution at Why AppDomain.CurrentDomain.BaseDirectory not contains "bin" in asp.net app?. It works for both Win Application and ASP.Net Web Application.

public string ApplicationPath
    {
        get
        {
            if (String.IsNullOrEmpty(AppDomain.CurrentDomain.RelativeSearchPath))
            {
                return AppDomain.CurrentDomain.BaseDirectory; //exe folder for WinForms, Consoles, Windows Services
            }
            else
            {
                return AppDomain.CurrentDomain.RelativeSearchPath; //bin folder for Web Apps 
            }
        }
    }

J
Jesse C. Slicer
string path = Path.GetDirectoryName(typeof(DaoTests).Module.FullyQualifiedName);

V
Valamas

This is what I came up with. In between web projects, unit tests (nunit and resharper test runner); I found this worked for me.

I have been looking for code to detect what configuration the build is in, Debug/Release/CustomName. Alas, the #if DEBUG. So if someone can improve that!

Feel free to edit and improve.

Getting app folder. Useful for web roots, unittests to get the folder of test files.

public static string AppPath
{
    get
    {
        DirectoryInfo appPath = new DirectoryInfo(AppDomain.CurrentDomain.BaseDirectory);

        while (appPath.FullName.Contains(@"\bin\", StringComparison.CurrentCultureIgnoreCase)
                || appPath.FullName.EndsWith(@"\bin", StringComparison.CurrentCultureIgnoreCase))
        {
            appPath = appPath.Parent;
        }
        return appPath.FullName;
    }
}

Getting bin folder: Useful for executing assemblies using reflection. If files are copied there due to build properties.

public static string BinPath
{
    get
    {
        string binPath = AppDomain.CurrentDomain.BaseDirectory;

        if (!binPath.Contains(@"\bin\", StringComparison.CurrentCultureIgnoreCase)
            && !binPath.EndsWith(@"\bin", StringComparison.CurrentCultureIgnoreCase))
        {
            binPath = Path.Combine(binPath, "bin");
            //-- Please improve this if there is a better way
            //-- Also note that apps like webapps do not have a debug or release folder. So we would just return bin.
#if DEBUG
            if (Directory.Exists(Path.Combine(binPath, "Debug"))) 
                        binPath = Path.Combine(binPath, "Debug");
#else
            if (Directory.Exists(Path.Combine(binPath, "Release"))) 
                        binPath = Path.Combine(binPath, "Release");
#endif
        }
            return binPath;
    }
}

P
Peter Mortensen

This should work:

ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
Assembly asm = Assembly.GetCallingAssembly();
String path = Path.GetDirectoryName(new Uri(asm.EscapedCodeBase).LocalPath);

string strLog4NetConfigPath = System.IO.Path.Combine(path, "log4net.config");

I am using this to deploy DLL file libraries along with some configuration file (this is to use log4net from within the DLL file).


What is fileMap used for here?
T
Tez Wingfield

I find my solution adequate for the retrieval of the location.

var executingAssembly = new FileInfo((Assembly.GetExecutingAssembly().Location)).Directory.FullName;

This is already one of the top-rated answers and is mentioned explicitly in the question as something that doesn't work in this situation.
Apologies must of missed that! Obviously I didn't read through thoroughly.
A
Andrey Bushman

I got the same behaviour in the NUnit in the past. By default NUnit copies your assembly into the temp directory. You can change this behaviour in the NUnit settings:

https://i.stack.imgur.com/VxmI7.png

Maybe TestDriven.NET and MbUnit GUI have the same settings.


Y
Yuck

I use this to get the path to the Bin Directory:

var i = Environment.CurrentDirectory.LastIndexOf(@"\");
var path = Environment.CurrentDirectory.Substring(0,i); 

You get this result:

"c:\users\ricooley\documents\visual studio 2010\Projects\Windows_Test_Project\Windows_Test_Project\bin"


I don't see a reason to avoid Path.getDirectoryName here
@MaxKeller If you don't see reasons, it doesn't mean that it is right. This alternative method of Path.GetDirectoryName is ten times faster.