我正在处理目录和文件的TreeView。用户可以选择一个文件或目录,然后对其进行操作。这要求我有一个方法,根据用户的选择执行不同的操作。

目前,我正在做这样的事情,以确定路径是文件还是目录:

bool bIsFile = false;
bool bIsDirectory = false;

try
{
    string[] subfolders = Directory.GetDirectories(strFilePath);

    bIsDirectory = true;
    bIsFile = false;
}
catch(System.IO.IOException)
{
    bIsFolder = false;
    bIsFile = true;
}

我不禁觉得有更好的方法可以做到这一点!我希望找到一个标准的。net方法来处理这个问题,但我还没有能够这样做。是否存在这样的方法,如果不存在,确定路径是文件还是目录的最直接的方法是什么?


当前回答

我使用以下,它还测试扩展,这意味着它可以用于测试,如果提供的路径是一个文件,但一个文件不存在。

private static bool isDirectory(string path)
{
    bool result = true;
    System.IO.FileInfo fileTest = new System.IO.FileInfo(path);
    if (fileTest.Exists == true)
    {
        result = false;
    }
    else
    {
        if (fileTest.Extension != "")
        {
            result = false;
        }
    }
    return result;
}

其他回答

我需要这个,posts帮助它,这让它变成一行,如果路径根本不是路径,它就会返回并退出方法。它解决了上述所有问题,也不需要后面的斜杠。

if (!Directory.Exists(@"C:\folderName")) return;

我使用以下,它还测试扩展,这意味着它可以用于测试,如果提供的路径是一个文件,但一个文件不存在。

private static bool isDirectory(string path)
{
    bool result = true;
    System.IO.FileInfo fileTest = new System.IO.FileInfo(path);
    if (fileTest.Exists == true)
    {
        result = false;
    }
    else
    {
        if (fileTest.Extension != "")
        {
            result = false;
        }
    }
    return result;
}

我在遇到类似的问题时遇到过这个问题,只不过我需要检查一个文件或文件夹的路径是否为文件或文件夹,而该文件或文件夹可能实际上并不存在。上面有一些关于答案的评论,提到它们不适用于这种情况。我找到了一个解决方案(我使用VB。NET,但你可以转换,如果你需要),这似乎很适合我:

Dim path As String = "myFakeFolder\ThisDoesNotExist\"
Dim bIsFolder As Boolean = (IO.Path.GetExtension(path) = "")
'returns True

Dim path As String = "myFakeFolder\ThisDoesNotExist\File.jpg"
Dim bIsFolder As Boolean = (IO.Path.GetExtension(path) = "")
'returns False

希望这能对别人有所帮助!

很晚才到这里,但我发现Nullable<Boolean>返回值相当难看- IsDirectory(字符串路径)返回null并不等于没有详细注释的不存在的路径,所以我提出了以下内容:

public static class PathHelper
{
    /// <summary>
    /// Determines whether the given path refers to an existing file or directory on disk.
    /// </summary>
    /// <param name="path">The path to test.</param>
    /// <param name="isDirectory">When this method returns, contains true if the path was found to be an existing directory, false in all other scenarios.</param>
    /// <returns>true if the path exists; otherwise, false.</returns>
    /// <exception cref="ArgumentNullException">If <paramref name="path"/> is null.</exception>
    /// <exception cref="ArgumentException">If <paramref name="path"/> equals <see cref="string.Empty"/></exception>
    public static bool PathExists(string path, out bool isDirectory)
    {
        if (path == null) throw new ArgumentNullException(nameof(path));
        if (path == string.Empty) throw new ArgumentException("Value cannot be empty.", nameof(path));

        isDirectory = Directory.Exists(path);

        return isDirectory || File.Exists(path);
    }
}

这个helper方法写得足够冗长和简洁,以便在第一次阅读时就能理解其意图。

/// <summary>
/// Example usage of <see cref="PathExists(string, out bool)"/>
/// </summary>
public static void Usage()
{
    const string path = @"C:\dev";

    if (!PathHelper.PathExists(path, out var isDirectory))
        return;

    if (isDirectory)
    {
        // Do something with your directory
    }
    else
    {
        // Do something with your file
    }
}

这是我所能想到的最好的Exists和Attributes属性的行为:

using System.IO;

public static class FileSystemInfoExtensions
{
    /// <summary>
    /// Checks whether a FileInfo or DirectoryInfo object is a directory, or intended to be a directory.
    /// </summary>
    /// <param name="fileSystemInfo"></param>
    /// <returns></returns>
    public static bool IsDirectory(this FileSystemInfo fileSystemInfo)
    {
        if (fileSystemInfo == null)
        {
            return false;
        }

        if ((int)fileSystemInfo.Attributes != -1)
        {
            // if attributes are initialized check the directory flag
            return fileSystemInfo.Attributes.HasFlag(FileAttributes.Directory);
        }

        // If we get here the file probably doesn't exist yet.  The best we can do is 
        // try to judge intent.  Because directories can have extensions and files
        // can lack them, we can't rely on filename.
        // 
        // We can reasonably assume that if the path doesn't exist yet and 
        // FileSystemInfo is a DirectoryInfo, a directory is intended.  FileInfo can 
        // make a directory, but it would be a bizarre code path.

        return fileSystemInfo is DirectoryInfo;
    }
}

下面是测试结果:

    [TestMethod]
    public void IsDirectoryTest()
    {
        // non-existing file, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentFile = @"C:\TotallyFakeFile.exe";

        var nonExistentFileDirectoryInfo = new DirectoryInfo(nonExistentFile);
        Assert.IsTrue(nonExistentFileDirectoryInfo.IsDirectory());

        var nonExistentFileFileInfo = new FileInfo(nonExistentFile);
        Assert.IsFalse(nonExistentFileFileInfo.IsDirectory());

        // non-existing directory, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentDirectory = @"C:\FakeDirectory";

        var nonExistentDirectoryInfo = new DirectoryInfo(nonExistentDirectory);
        Assert.IsTrue(nonExistentDirectoryInfo.IsDirectory());

        var nonExistentFileInfo = new FileInfo(nonExistentDirectory);
        Assert.IsFalse(nonExistentFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingDirectory = @"C:\Windows";

        var existingDirectoryInfo = new DirectoryInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryInfo.IsDirectory());

        var existingDirectoryFileInfo = new FileInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingFile = @"C:\Windows\notepad.exe";

        var existingFileDirectoryInfo = new DirectoryInfo(existingFile);
        Assert.IsFalse(existingFileDirectoryInfo.IsDirectory());

        var existingFileFileInfo = new FileInfo(existingFile);
        Assert.IsFalse(existingFileFileInfo.IsDirectory());
    }