C#相对路径转绝对路径，绝对路径转相对路径

1.绝对路径转相对路径

绝对转相对似乎C#没有提供实现，需要自己写，这里摘选了一位博友的实现方法：

string RelativePath(string absolutePath, string relativeTo)

        {

            //from - www.cnphp6.com

            string[] absoluteDirectories = absolutePath.Split('\\');

            string[] relativeDirectories = relativeTo.Split('\\');

            //Get the shortest of the two paths

            int length = absoluteDirectories.Length < relativeDirectories.Length ? absoluteDirectories.Length : relativeDirectories.Length;

            //Use to determine where in the loop we exited

            int lastCommonRoot = -;

            int index;

            //Find common root

            for (index = ; index < length; index++)

                if (absoluteDirectories[index] == relativeDirectories[index])

                    lastCommonRoot = index;

                else

                    break;

            //If we didn't find a common prefix then throw

            if (lastCommonRoot == -)

                throw new ArgumentException("Paths do not have a common base");

            //Build up the relative path

            StringBuilder relativePath = new StringBuilder();

            //Add on the ..

            for (index = lastCommonRoot + ; index < absoluteDirectories.Length; index++)

                if (absoluteDirectories[index].Length > )

                    relativePath.Append("..\\");

            //Add on the folders

            for (index = lastCommonRoot + ; index < relativeDirectories.Length - ; index++)

                relativePath.Append(relativeDirectories[index] + "\\");

            relativePath.Append(relativeDirectories[relativeDirectories.Length - ]);

            return relativePath.ToString();

        }

RelativePath

调用：

static void Main(string[] args)

{

    var path = RelativePath(@"D:\MyProj\Release", @"D:\MyProj\Log\MyFile.txt");

    Console.WriteLine(path);//print ..\Log\MyFile.txt

    Console.Read();

}

2.相对路径转绝对路径

可以直接用.Net自己的Path.GetFullPath转换。用SetCurrentDirectory改变当前比较路径

static void Main(string[] args)

{

    var relativePath = @"..\..\Release";

    //Directory.SetCurrentDirectory(...)

    Console.WriteLine(Path.GetFullPath(relativePath));

    Console.Read();

}