In my opinion this is a bug. The problem is that there are two different types of "absolute" paths. The path "d:\mydir\myfile.txt" is absolute, the path "\mydir\myfile.txt" is also considered to be "absolute" even though it is missing the drive letter. The correct behavior, in my opinion, would be to prepend the drive letter from the first path when the second path starts with the directory separator (and is not a UNC path). I would recommend writing your own helper wrapper function which has the behavior you desire if you need it.

如果你想在不丢失任何路径的情况下组合这两条路径，你可以使用这个:

?Path.Combine(@"C:\test", @"\test".Substring(0, 1) == @"\" ? @"\test".Substring(1, @"\test".Length - 1) : @"\test");

或者用变量:

string Path1 = @"C:\Test";
string Path2 = @"\test";
string FullPath = Path.Combine(Path1, Path2.IsRooted() ? Path2.Substring(1, Path2.Length - 1) : Path2);

这两种情况都返回“C:\test\test”。

首先，我计算Path2是否以/开头，如果为真，返回不带第一个字符的Path2。否则，返回完整的Path2。

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。

由于不知道实际的细节，我猜测它尝试像连接相对uri那样连接。例如:

urljoin('/some/abs/path', '../other') = '/some/abs/other'

这意味着当您使用前面的斜杠连接路径时，实际上是将一个基底连接到另一个基底，在这种情况下，第二个基底优先。

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;
}