复制目录的性能

Question

我正在使用C#将文件从一个目录复制到另一个目录.我正在使用来自msdn的代码,但它很慢,需要一分钟左右来复制几个演出.在资源管理器中只需几秒钟. http://channel9.msdn.com/Forums/TechOff/257490-How-Copy-directories-in-C 有一种更快的方式.. :)

        private static void Copy(string sourceDirectory, string targetDirectory)
    {
        DirectoryInfo diSource = new DirectoryInfo(sourceDirectory);
        DirectoryInfo diTarget = new DirectoryInfo(targetDirectory);

        CopyAll(diSource, diTarget);
    }

    private static void CopyAll(DirectoryInfo source, DirectoryInfo target)
    {
        // Check if the target directory exists, if not, create it.
        if (Directory.Exists(target.FullName) == false)
        {
            Directory.CreateDirectory(target.FullName);
        }

        // Copy each file into it's new directory.
        foreach (FileInfo fi in source.GetFiles())
        {
            fi.CopyTo(Path.Combine(target.ToString(), fi.Name), true);
        }

        // Copy each subdirectory using recursion.
        foreach (DirectoryInfo diSourceSubDir in source.GetDirectories())
        {
            DirectoryInfo nextTargetSubDir =
                target.CreateSubdirectory(diSourceSubDir.Name);
            CopyAll(diSourceSubDir, nextTargetSubDir);
        }
    }

---

使用Parallel我能够在比探索器和xcopy快一分钟内复制6gig.

---

private static void CopyAll(string SourcePath, string DestinationPath)
{
    string[] directories = System.IO.Directory.GetDirectories(SourcePath, "*.*", SearchOption.AllDirectories);

    Parallel.ForEach(directories, dirPath =>
    {
        Directory.CreateDirectory(dirPath.Replace(SourcePath, DestinationPath));
    }); 

    string[] files = System.IO.Directory.GetFiles(SourcePath, "*.*", SearchOption.AllDirectories);

    Parallel.ForEach(files, newPath =>
    {
        File.Copy(newPath, newPath.Replace(SourcePath, DestinationPath));
    }); 
}

Answer 1

你正在使用的是递归.它总是会减慢系统的速度.

使用它,因为它没有递归.

void CopyAll (string SourcePath, string DestinationPath)
{
    //Now Create all of the directories
    foreach (string dirPath in Directory.GetDirectories(SourcePath, "*.*", 
    SearchOption.AllDirectories))
    Directory.CreateDirectory(dirPath.Replace(SourcePath, DestinationPath));

    //Copy all the files
    foreach (string newPath in Directory.GetFiles(SourcePath, "*.*", 
    SearchOption.AllDirectories))
    File.Copy(newPath, newPath.Replace(SourcePath, DestinationPath));
}