Best way to get application folder path

I see that there are some ways to get the application folder path:

1. Application.StartupPath
2. System.IO.Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().Location)
3. AppDomain.CurrentDomain.BaseDirectory
4. System.IO.Directory.GetCurrentDirectory()
5. Environment.CurrentDirectory
6. System.IO.Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)
7. System.IO.Path.GetDirectory(Application.ExecutablePath)

What is the best way depending on the situation?

AppDomain.CurrentDomain.BaseDirectory is probably the most useful for accessing files whose location is relative to the application install directory.

In an ASP.NET application, this will be the application root directory, not the bin subfolder - which is probably what you usually want. In a client application, it will be the directory containing the main executable.

In a VSTO 2005 application, it will be the directory containing the VSTO managed assemblies for your application, not, say, the path to the Excel executable.

The others may return different directories depending on your environment - for example see @Vimvq1987's answer.

CodeBase is the place where a file was found and can be a URL beginning with http://. In which case Location will probably be the assembly download cache. CodeBase is not guaranteed to be set for assemblies in the GAC.

UPDATE These days (.NET Core, .NET Standard 1.3+ or .NET Framework 4.6+) it's better to use AppContext.BaseDirectory rather than AppDomain.CurrentDomain.BaseDirectory. Both are equivalent, but multiple AppDomains are no longer supported.

1. Application.StartupPathand 7. System.IO.Path.GetDirectoryName(Application.ExecutablePath) - Is only going to work for Windows Forms application

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

Is going to give you something like: "C:\\Windows\\Microsoft.NET\\Framework\\v4.0.30319\\Temporary ASP.NET Files\\legal-services\\e84f415e\\96c98009\\assembly\\dl3\\42aaba80\\bcf9fd83_4b63d101" which is where the page that you are running is.

3. AppDomain.CurrentDomain.BaseDirectory for web application could be useful and will return something like "C:\\hg\\Services\\Services\\Services.Website\\" which is base directory and is quite useful.

4. System.IO.Directory.GetCurrentDirectory() and 5. Environment.CurrentDirectory

will get you location of where the process got fired from - so for web app running in debug mode from Visual Studio something like "C:\\Program Files (x86)\\IIS Express"

6. System.IO.Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)

will get you location where .dll that is running the code is, for web app that could be "file:\\C:\\hg\\Services\\Services\\Services.Website\\bin"

Now in case of for example console app points 2-6 will be directory where .exe file is.

Hope this saves you some time.

Note that not all of these methods will return the same value. In some cases, they can return the same value, but be careful, their purposes are different:

Application.StartupPath

returns the StartupPath parameter (can be set when run the application)

System.IO.Directory.GetCurrentDirectory()

returns the current directory, which may or may not be the folder where the application is located. The same goes for Environment.CurrentDirectory. In case you are using this in a DLL file, it will return the path of where the process is running (this is especially true in ASP.NET).

For a web application, to get the current web application root directory, generally call by web page for the current incoming request:

HttpContext.Current.Server.MapPath();

System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath;

Above code description

I started a process from a Windows Service over the Win32 API in the session from the user which is actually logged in (in Task Manager session 1 not 0). In this was we can get to know, which variable is the best.

For all 7 cases from the question above, the following are the results:

Path1: C:\Program Files (x86)\MyProgram
Path2: C:\Program Files (x86)\MyProgram
Path3: C:\Program Files (x86)\MyProgram\
Path4: C:\Windows\system32
Path5: C:\Windows\system32
Path6: file:\C:\Program Files (x86)\MyProgram
Path7: C:\Program Files (x86)\MyProgram

Perhaps it's helpful for some of you, doing the same stuff, when you search the best variable for your case.

In my experience, the best way is a combination of these.

1. System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase Will give you the bin folder
2. Directory.GetCurrentDirectory() Works fine on .Net Core but not .Net and will give you the root directory of the project
3. System.AppContext.BaseDirectory and AppDomain.CurrentDomain.BaseDirectory Works fine in .Net but not .Net core and will give you the root directory of the project

In a class library that is supposed to target.Net and .Net core I check which framework is hosting the library and pick one or the other.

I have used this one successfully

System.IO.Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName)

It works even inside linqpad.

To get the path to .exe for simple desktop applications I use

Path.GetDirectoryName(Assembly.GetEntryAssembly().Location)

which returns path to .exe.
Also be aware that for several domains the .exe for default domain will be returned, or the .exe executed by first call of ExecuteAssembly(String) and that if the entry is unmanaged, the null will be returned.

Be careful with GetExecutingAssembly(), naming was confusing for me, as I have expected to get the .exe, but it returns the .dll or .exe, where the code is placed, so in case of GetExecutingAssembly() placed in library it returns the library.

Root directory:

DriveInfo cDrive = new DriveInfo(System.Environment.CurrentDirectory);
var driverPath = cDrive.RootDirectory;

this one System.IO.Path.GetDirectory(Application.ExecutablePath) changed to System.IO.Path.GetDirectoryName(Application.ExecutablePath)

If you know to get the root directory:

string rootPath = Path.GetPathRoot(Application.StartupPath)