c# - 获取文件时出现 UnauthorizedAccessException

Question

我正在创建一个在文件中找到重复项的应用程序。当我搜索以下文件时：

try
{
    string[] allFiles = Directory.GetFiles(
        directoryPath, "*.*", SearchOption.AllDirectories
    );

    for (int i = 0; i < allFiles.Length; i++)
    {
      //decisions
    }
}

catch (UnauthorizedAccessException ex)
{
    MessageBox.Show(ex.Message);
}

它说

拒绝访问路径“C:\$Recycle.Bin.......”。

我想如果一个文件夹不可访问然后移动到下一个但程序的执行在Directory.GetFiles方法处停止。

Answer 1

这是一个可以工作的课程：

public static class FileDirectorySearcher
{
    public static IEnumerable<string> Search(string searchPath, string searchPattern)
    {
        IEnumerable<string> files = GetFileSystemEntries(searchPath, searchPattern);

        foreach (string file in files)
        {
            yield return file;
        }

        IEnumerable<string> directories = GetDirectories(searchPath);

        foreach (string directory in directories)
        {
            files = Search(directory, searchPattern);

            foreach (string file in files)
            {
                yield return file;
            }
        }
    }

    private static IEnumerable<string> GetDirectories(string directory)
    {
        IEnumerable<string> subDirectories = null;
        try
        {
            subDirectories = Directory.EnumerateDirectories(directory, "*.*", SearchOption.TopDirectoryOnly);
        }
        catch (UnauthorizedAccessException)
        {
        }

        if (subDirectories != null)
        {
            foreach (string subDirectory in subDirectories)
            {
                yield return subDirectory;
            }
        }
    }

    private static IEnumerable<string> GetFileSystemEntries(string directory, string searchPattern)
    {
        IEnumerable<string> files = null;
        try
        {
            files = Directory.EnumerateFileSystemEntries(directory, searchPattern, SearchOption.TopDirectoryOnly);
        }
        catch (UnauthorizedAccessException)
        {
        }

        if (files != null)
        {
            foreach (string file in files)
            {
                yield return file;
            }
        }
    }
}

你可以像这样使用它：

IEnumerable<string> filesOrDirectories = FileDirectorySearcher.Search(@"C:\", "*.txt");

foreach (string fileOrDirectory in filesOrDirectories)
{
   // Do something here.
}

它是递归的，但是使用 yield 使它的内存占用很低（在我的测试中不到 10KB）。如果您只想要与模式匹配的文件而不是目录，只需替换EnumerateFileSystemEntries为EnumerateFiles.