这是. net Reflector for Path的反汇编代码。结合的方法。检查ispathoot函数。如果第二个路径是根路径(以DirectorySeparatorChar开头)，则返回第二个路径。

public static string Combine(string path1, string path2)
{
    if ((path1 == null) || (path2 == null))
    {
        throw new ArgumentNullException((path1 == null) ? "path1" : "path2");
    }
    CheckInvalidPathChars(path1);
    CheckInvalidPathChars(path2);
    if (path2.Length == 0)
    {
        return path1;
    }
    if (path1.Length == 0)
    {
        return path2;
    }
    if (IsPathRooted(path2))
    {
        return path2;
    }
    char ch = path1[path1.Length - 1];
    if (((ch != DirectorySeparatorChar) &&
         (ch != AltDirectorySeparatorChar)) &&
         (ch != VolumeSeparatorChar))
    {
        return (path1 + DirectorySeparatorChar + path2);
    }
    return (path1 + path2);
}


public static bool IsPathRooted(string path)
{
    if (path != null)
    {
        CheckInvalidPathChars(path);
        int length = path.Length;
        if (
              (
                  (length >= 1) &&
                  (
                      (path[0] == DirectorySeparatorChar) ||
                      (path[0] == AltDirectorySeparatorChar)
                  )
              )

              ||

              ((length >= 2) &&
              (path[1] == VolumeSeparatorChar))
           )
        {
            return true;
        }
    }
    return false;
}

这个\表示“当前驱动器的根目录”。在你的例子中，它指的是当前驱动器根目录中的“test”文件夹。所以，这可以等于"c:\test"。

这是. net Reflector for Path的反汇编代码。结合的方法。检查ispathoot函数。如果第二个路径是根路径(以DirectorySeparatorChar开头)，则返回第二个路径。

public static string Combine(string path1, string path2)
{
    if ((path1 == null) || (path2 == null))
    {
        throw new ArgumentNullException((path1 == null) ? "path1" : "path2");
    }
    CheckInvalidPathChars(path1);
    CheckInvalidPathChars(path2);
    if (path2.Length == 0)
    {
        return path1;
    }
    if (path1.Length == 0)
    {
        return path2;
    }
    if (IsPathRooted(path2))
    {
        return path2;
    }
    char ch = path1[path1.Length - 1];
    if (((ch != DirectorySeparatorChar) &&
         (ch != AltDirectorySeparatorChar)) &&
         (ch != VolumeSeparatorChar))
    {
        return (path1 + DirectorySeparatorChar + path2);
    }
    return (path1 + path2);
}


public static bool IsPathRooted(string path)
{
    if (path != null)
    {
        CheckInvalidPathChars(path);
        int length = path.Length;
        if (
              (
                  (length >= 1) &&
                  (
                      (path[0] == DirectorySeparatorChar) ||
                      (path[0] == AltDirectorySeparatorChar)
                  )
              )

              ||

              ((length >= 2) &&
              (path[1] == VolumeSeparatorChar))
           )
        {
            return true;
        }
    }
    return false;
}

我使用聚合函数强制路径组合，如下所示:

public class MyPath    
{
    public static string ForceCombine(params string[] paths)
    {
        return paths.Aggregate((x, y) => Path.Combine(x, y.TrimStart('\\')));
    }
}

原因:

第二个URL被认为是一个绝对路径，如果最后一个路径是一个绝对路径，Combine方法只会返回最后一个路径。

解决方案:

只需从第二个路径(/SecondPath到SecondPath)中删除前导斜杠/，它就会正常工作。

我想解决这个问题:

string sample1 = "configuration/config.xml";
string sample2 = "/configuration/config.xml";
string sample3 = "\\configuration/config.xml";

string dir1 = "c:\\temp";
string dir2 = "c:\\temp\\";
string dir3 = "c:\\temp/";

string path1 = PathCombine(dir1, sample1);
string path2 = PathCombine(dir1, sample2);
string path3 = PathCombine(dir1, sample3);

string path4 = PathCombine(dir2, sample1);
string path5 = PathCombine(dir2, sample2);
string path6 = PathCombine(dir2, sample3);

string path7 = PathCombine(dir3, sample1);
string path8 = PathCombine(dir3, sample2);
string path9 = PathCombine(dir3, sample3);

当然，所有路径1-9最后都应该包含一个等效的字符串。这是我想出的PathCombine方法:

private string PathCombine(string path1, string path2)
{
    if (Path.IsPathRooted(path2))
    {
        path2 = path2.TrimStart(Path.DirectorySeparatorChar);
        path2 = path2.TrimStart(Path.AltDirectorySeparatorChar);
    }

    return Path.Combine(path1, path2);
}

我还认为这是相当恼人的字符串处理必须手动完成，我对这背后的原因很感兴趣。