无法访问该文件，因为该文件正在使用中

Question

我需要使用 FileSystemWatcher 将操作从 dir1 同步到 dir2。当我在 dir1 中创建新文件时，相同的文件必须在 dir2 中，如果我删除/重命名/移动，也应该在 dir2 中。
当我在 dir1 中创建文件时，它也在 dir2 中创建，但是当我尝试重命名 dir1 中的文件时，我收到此异常：未处理的异常。 System.IO.IOException：该进程无法访问文件“C：\ Users \ artio \ Desktop \ FASassignment \ root \ dir1 \ g.txt”，因为它正在被另一个进程使用。当我用谷歌搜索时，这由于流未关闭，可能会出现错误，但我不知道我是否使用该流。另外，当我在其中创建子文件夹和文件时，我收到一条错误消息，指出未找到路径并且在 dir2 中未创建路径，您能帮我解决这两个错误吗？预先感谢！
程序：

public class Program2
{
    public static void Main(string[] args)
    {
        string sourcePath = @"C:\Users\artio\Desktop\FASassignment\root\dir1";
        string destinationPath = @"C:\Users\artio\Desktop\FASassignment\root\dir2";

        var source = new DirectoryInfo(sourcePath);
        var destination = new DirectoryInfo(destinationPath);

        using var sourceWatcher = new FileSystemWatcher(sourcePath);

        sourceWatcher.NotifyFilter = NotifyFilters.Attributes
                             | NotifyFilters.CreationTime
                             | NotifyFilters.DirectoryName
                             | NotifyFilters.FileName
                             | NotifyFilters.LastAccess
                             | NotifyFilters.LastWrite
                             | NotifyFilters.Security
                             | NotifyFilters.Size;

        sourceWatcher.Changed += OnChanged;
        sourceWatcher.Created += OnCreated;
        sourceWatcher.Deleted += OnDeleted;
        sourceWatcher.Renamed += OnRenamed;
        sourceWatcher.Error += OnError;

        sourceWatcher.Filter = "*.txt";
        sourceWatcher.IncludeSubdirectories = true;
        sourceWatcher.EnableRaisingEvents = true;

        Console.WriteLine("Press enter to exit.");
        Console.ReadLine();
    }

    private static void OnChanged(object sender, FileSystemEventArgs e)
    {
        if (e.ChangeType != WatcherChangeTypes.Changed)
        {
            return;
        }

        Console.WriteLine($"Changed: {e.FullPath}");
    }

    private static void OnCreated(object sender, FileSystemEventArgs e)
    {
        string value = $"Created: {e.FullPath}";

        string destinationPath = @"C:\Users\artio\Desktop\FASassignment\root\dir2";
        var name = e.Name;
        var fullPath = e.FullPath;
        string destination = Path.Combine(destinationPath, name);
        File.Copy(fullPath, destination,true);

        Console.WriteLine(value);
    }

    private static void OnDeleted(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine($"Deleted: {e.FullPath}");

        var name = e.Name;
        string destinationPath = @"C:\Users\artio\Desktop\FASassignment\root\dir2";
        string destination = Path.Combine(destinationPath, name);
        File.Delete(destination);
    }

    private static void OnRenamed(object sender, RenamedEventArgs e)
    {
        var oldFullPath = e.OldFullPath;
        var fullPath = e?.FullPath;
        Console.WriteLine($"Renamed:");
        Console.WriteLine($"    Old: {e.OldFullPath}");
        Console.WriteLine($"    New: {e.FullPath}");
        string destinationPath = @"C:\Users\artio\Desktop\FASassignment\root\dir2";

        string destination = Path.Combine(destinationPath, fullPath);
        File.Copy(fullPath, destination, true);
        File.Delete(oldFullPath);
    }

    private static void OnError(object sender, ErrorEventArgs e) =>
        PrintException(e.GetException());

    private static void PrintException(Exception? ex)
    {
        if (ex != null)
        {
            Console.WriteLine($"Message: {ex.Message}");
            Console.WriteLine("Stacktrace:");
            Console.WriteLine(ex.StackTrace);
            Console.WriteLine();
            PrintException(ex.InnerException);
        }
    }
}

Answer 1

您的问题是这一行：

string destination = Path.Combine(destinationPath, fullPath);

调试它，您会发现这不会导致您的想法。您正在尝试合并两个完整路径。

相反，使用这个：

private void OnRenamed(object sender, RenamedEventArgs e)
{                       
    Console.WriteLine($"Renamed:");
    Console.WriteLine($"    Old: {e.OldFullPath}");
    Console.WriteLine($"    New: {e.FullPath}");

    var oldFileName = Path.GetFileName(e.OldFullPath);
    var newFileName = Path.GetFileName(e.FullPath);
    var oldDestinationPath = Path.Combine(Destination, oldFileName);
    var newDestinationPath = Path.Combine(Destination, newFileName);
    var info = new FileInfo(oldDestinationPath);            
    info.MoveTo(newDestinationPath);
}

注意我没有使用 File 类。众所周知这是有问题的。

另外，我建议使用某种进程日志并重试，以便您可以恢复。否则，这可能会留下大量更改，因为文件可能会保留这些更改，从而可能导致操作失败。

更新：

关于您有关附加文件的其他问题，看起来您正在尝试在创建该文件的进程释放该文件的句柄之前访问该文件，因此您可以尝试引入一个小的延迟一秒钟或其他什么：

private void OnCreated(object sender, FileSystemEventArgs e)
{
    var name = e.Name;
    var fullPath = e.FullPath;
    string destination = Path.Combine(Destination, name);
    Console.WriteLine($"Copy to: {destination}");
    Thread.Sleep(1000); //Intentional delay
    File.Copy(fullPath, destination, true);
    Console.WriteLine("File copied successfully.");
}