23

我很惊讶没有可以采用字符串数组的重载。无论如何,避免嵌套调用 Path.Combine 的最佳方法是什么?

pathValue = Path.Combine(path1, Path.Combine(path2, Path.Combine(path3, path4)))

这似乎效率低下,因为它导致创建四个新字符串只是为了获得一个。

4

3 回答 3

27

如果您已经有一个数组或 IEnumerable<T> 那么您可以在一行中执行此操作...

// I'm assuming that you've got an array or IEnumerable<T> from somewhere
var paths = new string[] { path1, path2, path3, path4, path5, path6 };

string result = paths.Aggregate(Path.Combine);

如果没有,那么将您自己的扩展方法写入字符串...

public static class PathExtension
{
    public static string CombinePathWith(this string path1, string path2)
    {
        return Path.Combine(path1, path2);
    }
}

...这将允许您像这样链接这些...

string result = path1.CombinePathWith(path2)
                     .CombinePathWith(path3)
                     .CombinePathWith(path4)
                     .CombinePathWith(path5)
                     .CombinePathWith(path6);
于 2009-04-17T14:51:28.523 回答
23

事物的效率方面不是 IMO 的问题 - 它是事物的可用性方面。我个人认为应该超载:

Combine(string first, string second, string third, params string[] others)

如果您只是编写,您至少需要三个以防止它与现有的双参数版本发生冲突,Path.Combine("foo", "bar")但这肯定有助于使代码更清晰。为什么不在Connect上打开功能请求?

当然,您可以自己实现它(在另一个类中,参数的数量并不重要):

public static string CombinePaths(string first, params string[] others)
{
    // Put error checking in here :)
    string path = first;
    foreach (string section in others)
    {
        path = Path.Combine(path, section);
    }
    return path;
}
于 2009-04-17T14:33:39.503 回答
1

自己实现它非常简单:

public string Combine(params string[] paths)
{
    char[] pathSeparators = new char[] 
        { Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar, Path.VolumeSeparatorChar };

    if(paths == null) throw new ArgumentNullException("paths");
    if(paths.Length == 1) return paths[0];

    StringBuilder pathBuilder = new StringBuilder();

    foreach(string path in paths)
    {
        if(Path.IsPathRooted(path))
            pathBuilder = new StringBuilder(path);
        else
        {
            char last = pathBuilder.Length > 0 ?
                pathBuilder[pathBuilder.Length - 1] :
                path[path.Length - 1];

            if(Array.IndexOf(pathSeparators, last) == -1)
                pathBuilder.Append(Path.DirectorySeparatorChar);

            pathBuilder.Append(path);
        } // else
    } // foreach

    return pathBuilder.ToString();
}

[Test()]
public void CombinePaths()
{
    string result = Combine(@"C:\Program Files\", @"Microsoft.NET", @"ADOMD.NET\", "90", "msadomdx.dll");
    Assert.AreEqual(@"C:\Program Files\Microsoft.NET\ADOMD.NET\90\msadomdx.dll", result);
}
于 2009-04-17T14:40:05.150 回答