In C#, how do I combine more than two parts of a file path at once?

Question

To combine two parts of a file path, you can do

System.IO.Path.Combine (path1, path2); 

However, you can't do

System.IO.Path.Combine (path1, path2, path3); 

Is there a simple way to do this?

Answer 1

Here's a utility method you can use:

public static string CombinePaths(string path1, params string[] paths) {     if (path1 == null)     {         throw new ArgumentNullException("path1");     }     if (paths == null)     {         throw new ArgumentNullException("paths");     }     return paths.Aggregate(path1, (acc, p) => Path.Combine(acc, p)); } 

Alternate code-golf version (shorter, but not quite as clear, semantics are a bit different from Path.Combine):

public static string CombinePaths(params string[] paths) {     if (paths == null)     {         throw new ArgumentNullException("paths");     }     return paths.Aggregate(Path.Combine); } 

Then you can call this as:

string path = CombinePaths(path1, path2, path3); 

Answer 2

As others have said, in .NET 3.5 and earlier versions there hasn't been a way to do this neatly - you either have to write your own Combine method or call Path.Combine multiple times.

But rejoice - for in .NET 4.0, there is this overload:

public static string Combine(     params string[] paths ) 

There are also overloads taking 3 or 4 strings, presumably so that it doesn't need to create an array unnecessarily for common cases.

Hopefully Mono will port those overloads soon - I'm sure they'd be easy to implement and much appreciated.