FileStream异步读写文件，CPU超高！
问题
-
如图，WPF的DataGrid中添加了DataGridTemplateColumn，用于展示远程服务器的文件，点开始按钮后开始获取文件并下载到本地。
每个下载任务中采用异步Task，过程中发现开启单个或多个下载任务时都会占用CPU很高，如何优化？
后台：
public ObservableCollection<FileInfo> fileInfoCollection = new ObservableCollection<FileInfo>(); public void StartDownLoad(string sourceFilePath, string localFilePath, int fileIndex) { if (!fileInfoCollection[fileIndex].IsStart) { Task.Run( async () => { await DwonLoadFile(sourceFilePath, localFilePath, fileIndex); }); } } private async Task DwonLoadFile(string sourceFilePath, string localFilePath, int fileIndex) { if (!File.Exists(sourceFilePath)) return; WebRequest request = WebRequest.Create(sourceFilePath); WebResponse response = await request.GetResponseAsync(); Stream netStream = response.GetResponseStream(); Stream fileStream = new FileStream(localFilePath, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite); fileStream.Position = 0; byte[] read = new byte[1024]; long progressBarValue = 0; int realReadLen = await netStream.ReadAsync(read, 0, read.Length); Thread thread = new Thread(new ThreadStart(async delegate { while (realReadLen > 0 && !fileInfoCollection[fileIndex].IsStopped) { if (fileInfoCollection[fileIndex].IsSuspend == false) { await fileStream.WriteAsync(read, 0, realReadLen); progressBarValue += realReadLen; double len = double.Parse((progressBarValue / 1024.00 / 1024.00).ToString("F2")); fileInfoCollection[fileIndex].CompletePercentage = Math.Ceiling(((double)progressBarValue / (double)netStream.Length) * 100) + "%"; fileInfoCollection[fileIndex].CompletedProgress = len; fileInfoCollection[fileIndex].ProgressBarValue = progressBarValue; realReadLen = await netStream.ReadAsync(read, 0, read.Length); continue; } Thread.Sleep(1); } netStream.Close(); fileStream.Close(); })); thread.IsBackground = true; thread.Start(); }前台：
private void SuspendOrStartBtn_Click(object sender, RoutedEventArgs e) { FileInfo item = ((Button)sender).DataContext as FileInfo; int index = FileDataGrid.Items.IndexOf(item); //开始任务 if (fileManager.fileInfoCollection[index].IsSuspend==true) { fileManager.StartDownLoad(item.SourceFileFullName, @"D:\" + item.SourceFileName, index); fileManager.fileInfoCollection[index].IsStart = true; fileManager.fileInfoCollection[index].IsSuspend = false; SetPauseResumeButtonText(index); } else//暂停任务 { fileManager.fileInfoCollection[index].IsSuspend = true; SetPauseResumeButtonText(index); } }
