Question

检查目录1是否是目录2的子目录是一种简单的方法，反之亦然？

我检查了Path和DirectoryInfo帮助类，但没有发现系统就绪函数。我以为它会在某处。

你们有个想法在哪里找到这个吗？

我自己试着写一张支票，但这比我开始时的预期要复杂得多。

Answer 1

在回答问题的第一部分时：“dir1是dir2的子目录吗？”，此代码应该有效：

public bool IsSubfolder(string parentPath, string childPath)
{
    var parentUri = new Uri(parentPath);
    var childUri = new DirectoryInfo(childPath).Parent;
    while (childUri != null)
    {
        if(new Uri(childUri.FullName) == parentUri)
        {
            return true;
        }
        childUri = childUri.Parent;
    }
    return false;
}

URI（在Windows上至少在Mono / Linux上可能不同）不区分大小写。如果区分大小写很重要，请改用Compare上的Uri方法。

Answer 2

使用Uri类这是一种更简单的方法：

var parentUri = new Uri(parentPath);
var childUri = new Uri(childPath);
if (parentUri != childUri && parentUri.IsBaseOf(childUri))
{
   //dowork
}

Answer 3

请在此处查看原始答案：https://stackoverflow.com/a/31941159/134761

不区分大小写
容忍\和/文件夹分隔符的混合
在路径中容忍..\
避免部分文件夹名称匹配（c:\foobar而不是c:\foo的子路径

代码：

public static class StringExtensions
{
    /// <summary>
    /// Returns true if <paramref name="path"/> starts with the path <paramref name="baseDirPath"/>.
    /// The comparison is case-insensitive, handles / and \ slashes as folder separators and
    /// only matches if the base dir folder name is matched exactly ("c:\foobar\file.txt" is not a sub path of "c:\foo").
    /// </summary>
    public static bool IsSubPathOf(this string path, string baseDirPath)
    {
        string normalizedPath = Path.GetFullPath(path.Replace('/', '\\')
            .WithEnding("\\"));

        string normalizedBaseDirPath = Path.GetFullPath(baseDirPath.Replace('/', '\\')
            .WithEnding("\\"));

        return normalizedPath.StartsWith(normalizedBaseDirPath, StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>
    /// Returns <paramref name="str"/> with the minimal concatenation of <paramref name="ending"/> (starting from end) that
    /// results in satisfying .EndsWith(ending).
    /// </summary>
    /// <example>"hel".WithEnding("llo") returns "hello", which is the result of "hel" + "lo".</example>
    public static string WithEnding([CanBeNull] this string str, string ending)
    {
        if (str == null)
            return ending;

        string result = str;

        // Right() is 1-indexed, so include these cases
        // * Append no characters
        // * Append up to N characters, where N is ending length
        for (int i = 0; i <= ending.Length; i++)
        {
            string tmp = result + ending.Right(i);
            if (tmp.EndsWith(ending))
                return tmp;
        }

        return result;
    }

    /// <summary>Gets the rightmost <paramref name="length" /> characters from a string.</summary>
    /// <param name="value">The string to retrieve the substring from.</param>
    /// <param name="length">The number of characters to retrieve.</param>
    /// <returns>The substring.</returns>
    public static string Right([NotNull] this string value, int length)
    {
        if (value == null)
        {
            throw new ArgumentNullException("value");
        }
        if (length < 0)
        {
            throw new ArgumentOutOfRangeException("length", length, "Length is less than zero");
        }

        return (length < value.Length) ? value.Substring(value.Length - length) : value;
    }
}

测试用例（NUnit）：

[TestFixture]
public class StringExtensionsTest
{
    [TestCase(@"c:\foo", @"c:", Result = true)]
    [TestCase(@"c:\foo", @"c:\", Result = true)]
    [TestCase(@"c:\foo", @"c:\foo", Result = true)]
    [TestCase(@"c:\foo", @"c:\foo\", Result = true)]
    [TestCase(@"c:\foo\", @"c:\foo", Result = true)]
    [TestCase(@"c:\foo\bar\", @"c:\foo\", Result = true)]
    [TestCase(@"c:\foo\bar", @"c:\foo\", Result = true)]
    [TestCase(@"c:\foo\a.txt", @"c:\foo", Result = true)]
    [TestCase(@"c:\FOO\a.txt", @"c:\foo", Result = true)]
    [TestCase(@"c:/foo/a.txt", @"c:\foo", Result = true)]
    [TestCase(@"c:\foobar", @"c:\foo", Result = false)]
    [TestCase(@"c:\foobar\a.txt", @"c:\foo", Result = false)]
    [TestCase(@"c:\foobar\a.txt", @"c:\foo\", Result = false)]
    [TestCase(@"c:\foo\a.txt", @"c:\foobar", Result = false)]
    [TestCase(@"c:\foo\a.txt", @"c:\foobar\", Result = false)]
    [TestCase(@"c:\foo\..\bar\baz", @"c:\foo", Result = false)]
    [TestCase(@"c:\foo\..\bar\baz", @"c:\bar", Result = true)]
    [TestCase(@"c:\foo\..\bar\baz", @"c:\barr", Result = false)]
    public bool IsSubPathOfTest(string path, string baseDirPath)
    {
        return path.IsSubPathOf(baseDirPath);
    }
}

更新2015-08-18：修复部分文件夹名称的错误匹配。添加测试用例。

更新2016-01-29：链接到原始问题https://stackoverflow.com/a/31941159/134761

Answer 4

如果你有两条路，请看看：

Normalize directory names in C#

http://filedirectorypath.codeplex.com/（我不知道它的质量）

并使用此：

var ancestor = new DirectoryPathAbsolute(ancestorPath);
var child = new DirectoryPathAbsolute(childPath);

var res = child.IsChildDirectoryOf(ancestor); //I don't think it actually checks for case-sensitive filesystems

否则，如果您想知道某个目录是否作为路径中的子目录存在，请查看：

Directory.EnumerateDirectories

进入.Net 4.0。例如：

path是否包含以Console开头的目录：

//* is a wildcard. If you remove it, it search for directories called "Console"
var res = Directory.EnumerateDirectories(@path, "Console*", SearchOption.AllDirectories).Any();

Answer 5

DirectoryInfo有一个属性Parent，它也是一个DirectoryInfo类型。您可以使用它来确定您的目录是否是父目录的子目录。

Answer 6

第二个目录（d2）全名将包含第一个目录（d1）的全名，如果它是d1的子文件夹。

这假设您使用的是有效目录

if (d2.FullName.Contains(d1.FullName))
{
     //dowork
}

如果您需要检查映射驱动器，可以尝试

    static void Main(string[] args)
    {
        if (GetUNCPath(d2.FullName).ToLower().Contains(GetUNCPath(d1.FullName).ToLower()))
        {
        }
    }

    [DllImport("mpr.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    private static extern int WNetGetConnection(
        [MarshalAs(UnmanagedType.LPTStr)] string localName,
        [MarshalAs(UnmanagedType.LPTStr)] StringBuilder remoteName, ref int length);

    private static string GetUNCPath(string originalPath)
    {

        StringBuilder sb = new StringBuilder(512);
        int size = sb.Capacity;
        // look for the {LETTER}: combination ...
        if (originalPath.Length > 2 && originalPath[1] == ':')
        {
            // don't use char.IsLetter here - as that can be misleading
            // the only valid drive letters are a-z && A-Z.
            char c = originalPath[0];
            if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
            {
                int error = WNetGetConnection(originalPath.Substring(0, 2), sb, ref size);
                if (error == 0)
                {
                    DirectoryInfo dir = new DirectoryInfo(originalPath);
                    string path = Path.GetFullPath(originalPath).Substring(Path.GetPathRoot(originalPath).Length);
                    return Path.Combine(sb.ToString().TrimEnd(), path);
                }
            }
        }
        return originalPath;
    }

从http://social.msdn.microsoft.com/Forums/en/csharpgeneral/thread/6f79f2b3-d092-431f-bc28-d15d93cf5d09

获取的映射驱动器代码

Answer 7

您可以使用Path.GetDirectoryName Method 获取父目录。它也适用于目录。

Answer 8

public static bool IsSubfolder(DirectoryInfo parentPath, DirectoryInfo childPath)
{
return parentPath.FullName.StartsWith(childPath.FullName+Path.DirectorySeparatorChar);
}

Answer 9

在angularsen's answer中编写的出色测试案例的帮助下，我在用于Windows的.NET Core 3.1上编写了以下更简单的扩展方法：

public static bool IsSubPathOf(this string dirPath, string baseDirPath)
{
    dirPath = dirPath.Replace('/', '\\');
    if (!dirPath.EndsWith('\\'))
    {
        dirPath += '\\';
    }

    baseDirPath = baseDirPath.Replace('/', '\\');
    if (!baseDirPath.EndsWith('\\'))
    {
        baseDirPath += '\\';
    }

    var dirPathUri = new Uri(dirPath).LocalPath;
    var baseDirUri = new Uri(baseDirPath).LocalPath;

    return dirPathUri.Contains(baseDirUri, StringComparison.OrdinalIgnoreCase);
}

Answer 10

这是我得到的，在首先验证两个目录路径字符串是什么并且以路径格式我知道之后：shouldnotbechilddirpath.ToUpper().StartsWith(maybeparentdirpath.ToUpper())

如果您可能在区分大小写的文件系统中工作，请务必取出ToUppers（）。

Answer 11

在两种情况下使用DirectoryInfo时，您可以将directory2与directory1的Parent property进行比较。

DirectoryInfo d1 = new DirectoryInfo(@"C:\Program Files\MyApp");
DirectoryInfo d2 = new DirectoryInfo(@"C:\Program Files\MyApp\Images");

if(d2.Parent.FullName == d1.FullName)
{
    Console.WriteLine ("Sub directory");
}

如何检查目录1是否是dir2的子目录，反之亦然

11 个答案: