C＃比较基于名称未返回完整路径的文件列表

Posted 2021-04-07

我正在编写一种方法，我希望能够根据文件名比较来自2个不同目录的文件列表，然后将第2个目录中不存在的所有文件存储到稍后要使用的列表中（最有可能创建另一种方法来复制/移动这些文件）。

在我查看文件列表（FilesRemaiing list）并尝试获取文件的完整路径之前，所有内容似乎都正常工作。它最终指向我的bin / debug路径。

我相信这是因为在我的查询中，我特意查询要比较的file.Name，而不是file.FullName。原因是因为FullName将返回路径以及文件名，我不能将其用于比较语句（var FilesRemaining = FileList1.Except（FileList2）.ToList（）;）。

所以我的问题是，如何根据名称比较2组文件，然后将例外列表的完整路径存储到第3个列表，我可以在以后用于复制/移动？

这是我的方法：

   public static List<string> CompareFiles(string ComparePath1, string ComparePath2)
    {
        List<string> FileList1 = new List<string>();
        List<string> FileList2 = new List<string>();
        List<string> CompareFileList = new List<string>();
        DirectoryInfo directory1 = new DirectoryInfo(ComparePath1);
        FileInfo[] files1 = directory1.GetFiles("*.*", SearchOption.TopDirectoryOnly);
        DirectoryInfo directory2 = new DirectoryInfo(ComparePath2);
        FileInfo[] files2 = directory2.GetFiles("*.*", SearchOption.TopDirectoryOnly);

        //Queries the given directory for filenames
        var query1 = from file in files1
                where (!file.Attributes.HasFlag(FileAttributes.Hidden))
                    select (file.Name);
        foreach (var file in query1)
        {
            FileList1.Add(file);
        }

        var query2 = from file in files2
                    where (!file.Attributes.HasFlag(FileAttributes.Hidden))
                    select (file.Name);
        foreach (var file in query2)
        {
            FileList2.Add(file);
        }

        var FilesRemaining = FileList1.Except(FileList2).ToList();

        foreach (var file in FilesRemaining)
        {
            string fullFile = Path.GetFullPath(file);
            CompareFileList.Add(fullFile);
            Console.WriteLine(fullFile);
        }

        return CompareFileList;

    }

答案

使用此方法，您可以保留FileInfo对象，并仅使用其名称计算“除外”列表。

//More efficient way to get your files.
IEnumerable<FileInfo> files1 = directory1
    .GetFiles("*.*", SearchOption.TopDirectoryOnly)
    .Where(x => !x.Attributes.HasFlag(FileAttributes.Hidden));
IEnumerable<FileInfo> files2 = directory2
    .GetFiles("*.*", SearchOption.TopDirectoryOnly)
    .Where(x => !x.Attributes.HasFlag(FileAttributes.Hidden));

//It uses the FileNameComparer class to compare to values.
IEnumerable<FileInfo> filesRemaining = files1.Except(files2, new FileNameComparer());

这是FileNameComparer类。

public class FileNameComparer : IEqualityComparer<FileInfo>
{
    public bool Equals(FileInfo x, FileInfo y)
    {
        //Here is where the magic is happening.
        return x.Name == y.Name;
    }

    //You need this too, altougt, I am not quite sure when it gets used.
    public int GetHashCode(FileInfo obj)
    {

        return obj.Name.GetHashCode();
    }
}

另一答案

class Program
{
    static void Main(string[] args)
    {
        foreach ( var f in CompareFiles(@"x:	mpdir_1", @"x:	mpdir_2") )
        {
            Console.WriteLine(f);
        }

        Console.ReadKey();
    }

    public static List<string> CompareFiles(string comparePath1, string comparePath2)
    {
        //Queries the given directory for filenames
        var fileList1 = (from file in new DirectoryInfo(comparePath1).GetFiles("*.*", SearchOption.TopDirectoryOnly)
                         where !file.Attributes.HasFlag(FileAttributes.Hidden)
                         select file.Name).ToList();

        var fileList2 = (from file in new DirectoryInfo(comparePath2).GetFiles("*.*", SearchOption.TopDirectoryOnly)
                         where !file.Attributes.HasFlag(FileAttributes.Hidden)
                         select file.Name).ToList();
        return fileList1.Except(fileList2)
                        .Select(file => Path.Combine(comparePath1, file))
                        .ToList();
    }
}