在查看多个问题/答案后，我无法找到解决问题的方法。我记得我从StackOverflow的一些问题中得到了这个代码，它完美地运行但仅适用于一个文件。我想要的是多个文件。
这是原始的CopyTo功能：
public static void CopyTo(this FileInfo file, FileInfo destination, Action<int> progressCallback)
{
const int bufferSize = 1024 * 1024; //1MB
byte[] buffer = new byte[bufferSize], buffer2 = new byte[bufferSize];
bool swap = false;
int progress = 0, reportedProgress = 0, read = 0;
long len = file.Length;
float flen = len;
Task writer = null;
using (var source = file.OpenRead())
using (var dest = destination.OpenWrite())
{
//dest.SetLength(source.Length);
for (long size = 0; size < len; size += read)
{
if ((progress = ((int)((size / flen) * 100))) != reportedProgress)
progressCallback(reportedProgress = progress);
read = source.Read(swap ? buffer : buffer2, 0, bufferSize);
writer?.Wait(); // if < .NET4 // if (writer != null) writer.Wait();
writer = dest.WriteAsync(swap ? buffer : buffer2, 0, read);
swap = !swap;
}
writer?.Wait(); //Fixed - Thanks @sam-hocevar
}
}
以下是我开始文件复制过程的方法：
var ficheiro = ficheirosCopia.ElementAt(x);
var _source = new FileInfo(ficheiro.Key);
var _destination = new FileInfo(ficheiro.Value);
if (_destination.Exists)
{
_destination.Delete();
}
Task.Run(() =>
{
_source.CopyTo(_destination, perc => Dispatcher.Invoke(() => progressBar.SetProgress(perc)));
}).GetAwaiter().OnCompleted(() => MessageBox.Show("File Copied!"));
当我只复制一个文件但我需要复制多个文件时，这非常有效。所以我开始改变一些事情：
public static void CopyTo(Dictionary<string, string> files, Action<int> progressCallback)
{
int globalProgress = 0, globalReportedProgress = 0, globalRead = 0;
for (var x = 0; x < files.Count; x++)
{
var item = files.ElementAt(x);
var file = new FileInfo(item.Key);
var destination = new FileInfo(item.Value);
const int bufferSize = 1024 * 1024; //1MB
byte[] buffer = new byte[bufferSize], buffer2 = new byte[bufferSize];
bool swap = false;
int progress = 0, reportedProgress = 0, read = 0;
long len = file.Length;
float flen = len;
Task writer = null;
using (var source = file.OpenRead())
using (var dest = destination.OpenWrite())
{
for (long size = 0; size < len; size += read)
{
if ((progress = ((int)((size / flen) * 100))) != reportedProgress)
progressCallback(reportedProgress = progress);
read = source.Read(swap ? buffer : buffer2, 0, bufferSize);
writer?.Wait(); // if < .NET4 // if (writer != null) writer.Wait();
writer = dest.WriteAsync(swap ? buffer : buffer2, 0, read);
swap = !swap;
}
writer?.Wait(); //Fixed - Thanks @sam-hocevar
}
}
}
当然这段代码有很多错误，但我不明白应该怎么做。
主要目标是为多个磁贴启动单个任务，并为全局复制启用progresscallback。接收字典（它已经在代码的其他部分创建）作为参数。
答案 0 :(得分：0)
为此我想出了两种方法，一种是在每个文件之后报告进度，另一种是每 n 个字节报告进度。
namespace StackOverflow41750117CopyProgress
{
using System;
using System.Collections.Generic;
using System.IO;
public class Batch
{
private bool _overwrite;
/// <summary>
/// Initializes a new instance of the <see cref="Batch"/> class.
/// </summary>
/// <param name="overwrite">
/// True to overwrite the destination file if it already exists (default),
/// false to throw an exception if the destination file already exists.
/// </param>
public Batch(bool overwrite = true)
{
this._overwrite = overwrite;
}
/// <summary>
/// Copies the files, reporting progress once per file.
/// </summary>
/// <param name="filesToCopy">
/// A dictionary with the paths of the source files as its keys, and the path to the destination file as its values.
/// </param>
/// <param name="progressCallback">
/// A callback which accepts two Int64 parameters - the number of bytes copied so far, and the total number of bytes to copy.
/// </param>
public void CopyReportingPerFile(Dictionary<string, string> filesToCopy, Action<long, long> progressCallback)
{
var bytesToCopy = this.GetTotalFileSize(filesToCopy);
long totalBytesCopied = 0;
foreach (var copy in filesToCopy)
{
File.Copy(copy.Key, copy.Value, this._overwrite);
totalBytesCopied += new FileInfo(copy.Key).Length;
progressCallback(totalBytesCopied, bytesToCopy);
}
}
/// <summary>
/// Copies the files, reporting progress once per read/write operation.
/// </summary>
/// <param name="filesToCopy">
/// A dictionary with the paths of the source files as its keys, and the path to the destination file as its values.
/// </param>
/// <param name="progressCallback">
/// A callback which accepts two Int64 parameters - the number of bytes copied so far, and the total number of bytes to copy.
/// </param>
public void CopyReportingPerBuffer(Dictionary<string, string> filesToCopy, Action<long, long> progressCalllback)
{
var bytesToCopy = this.GetTotalFileSize(filesToCopy);
var bufferSize = 1024 * 1024 * 50;
var buffer = new byte[bufferSize];
var span = new Span<byte>(buffer);
long totalBytesCopied = 0;
foreach (var copy in filesToCopy)
{
using (var source = File.OpenRead(copy.Key))
using (var destination = File.OpenWrite(copy.Value))
{
int bytesRead = 0;
do
{
// The Read method returns 0 once we've reached the end of the file
bytesRead = source.Read(span);
destination.Write(span);
totalBytesCopied += bytesRead;
progressCalllback(totalBytesCopied, bytesToCopy);
} while (bytesRead > 0);
source.Close();
destination.Close();
}
}
}
private long GetTotalFileSize(Dictionary<string, string> filesToCopy)
{
long bytesToCopy = 0;
foreach (var filename in filesToCopy.Keys)
{
var fileInfo = new FileInfo(filename);
bytesToCopy += fileInfo.Length;
}
return bytesToCopy;
}
}
}
用法：
namespace StackOverflow41750117CopyProgress
{
using System;
using System.Collections.Generic;
using System.IO;
public class Program
{
public static void Main(string[] args)
{
var filesToCopy = new Dictionary<string, string>();
filesToCopy.Add(@"C:\temp\1.mp4", @"C:\temp\1copy.mp4");
filesToCopy.Add(@"C:\temp\2.mp4", @"C:\temp\2copy.mp4");
filesToCopy.Add(@"C:\temp\3.mp4", @"C:\temp\3copy.mp4");
filesToCopy.Add(@"C:\temp\4.mp4", @"C:\temp\4copy.mp4");
filesToCopy.Add(@"C:\temp\5.mp4", @"C:\temp\5copy.mp4");
filesToCopy.Add(@"C:\temp\6.mp4", @"C:\temp\6copy.mp4");
filesToCopy.Add(@"C:\temp\7.mp4", @"C:\temp\7copy.mp4");
// Make sure the destination files don't already exist
foreach (var copy in filesToCopy)
{
File.Delete(copy.Value);
}
var batch = new Batch();
Console.WriteLine($"Started {DateTime.Now}");
batch.CopyReportingPerFile(filesToCopy, (bytesCopied, bytesToCopy) => Console.WriteLine($"Copied {bytesCopied} bytes of {bytesToCopy}"));
//batch.CopyReportingPerBuffer(filesToCopy, (bytesCopied, bytesToCopy) => Console.WriteLine($"Copied {bytesCopied} bytes of {bytesToCopy}"));
Console.WriteLine($"Finished {DateTime.Now}");
}
}
}
一些观察...
Console.Writeline 中调用 progressCallback不那么频繁，而不是提高磁盘 I/O 的速度。Span<byte> 而不是 byte[] 用于读取和写入数据的缓冲区 - 这消除了我的代码跟踪文件中当前位置的需要（这是我今天学到的新东西）。我知道我回答这个问题已经晚了，但希望有人会觉得这很有用。