How can I use IndexOf to pick a specific Character when there are more than one of them?

Question

How can I use IndexOf with SubString to pick a specific Character when there are more than one of them? Here's my issue. I want to take the path "C:\Users\Jim\AppData\Local\Temp\" and remove the "Temp\" part. Leaving just "C:\Users\Jim\AppData\Local\" I have solved my problem with the code below but this assumes that the "Temp" folder is actually called "Temp". Is there a better way? Thanks

if (Path.GetTempPath() != null) // Is it there?{
tempDir = Path.GetTempPath(); //Make a string out of it.
int iLastPos = tempDir.LastIndexOf(@"\");
if (Directory.Exists(tempDir) && iLastPos > tempDir.IndexOf(@"\"))
{
    // Take the position of the last "/" and subtract 4.
    // 4 is the lenghth of the word "temp".
    tempDir = tempDir.Substring(0, iLastPos - 4);
}}

Answer 1

The better way is to use Directory.GetParent() or DirectoryInfo.Parent:

using System;
using System.IO;

class Test
{
    static void Main()
    {
        string path = @"C:\Users\Jim\AppData\Local\Temp\";
        DirectoryInfo dir = new DirectoryInfo(path);
        DirectoryInfo parent = dir.Parent;
        Console.WriteLine(parent.FullName);
    }    
}

(Note that Directory.GetParent(path) just gives you the Temp directory, as it doesn't understand that the path is already meant to be a directory.)

If you really wanted to use LastIndexOf though, use the overload which allows you to specify the start location.

Answer 2

Why not just handle this directly using the System classes?

string folder = Environment.GetFolder(Environment.SpecialFolder.LocalApplicationData);

Answer 3

I would use the DirectoryInfo class.

DirectoryInfo tempDirectory = new DirectoryInfo(Path.GetTempPath());            
DirectoryInfo tempDirectoryParent = tempDirectory.Parent;

Answer 4

The other answerers have shown the best way to accomplish your goal. In the interest of expanding your knowledge further, I suggest that you look at regular expressions for your string matching and replacement needs, in general.

I spent the first couple of years of my self-taught programming career doing the most convoluted string manipulation imaginable before I realized that someone else had already solved all these problems, and I picked up a copy of Mastering Regular Expressions. I strongly recommend it.

One way to strip off the last directory is with the following regular expression:

tempDir = Regex.Match(tempDir, @".*(?=\\[^\\]+)\\?").Value;

It may look cryptic, but this will actually remove the last item from the path, regardless of its name, and regardless of whether there is another \ at the end.