task 相关问题

我正在编写一个端口扫描仪，无法创建流畅的用户界面。我有一个显示扫描结果的 DataGrid：我正在编写一个端口扫描器，无法创建流畅的 UI。我有一个显示扫描结果的DataGrid： <DataGrid Grid.Column="0" ItemsSource="{Binding NetScanResults}" Margin="5" AutoGenerateColumns="False" IsReadOnly="True"> 然后我有一个保存扫描结果的对象。 public class NetScanResult : ObservableObject { private IPAddress ipAddress; public IPAddress IpAddress { get => ipAddress; set { SetProperty(ref ipAddress, value); OnPropertyChanged(nameof(IpAddressStr)); } } private ObservableCollection<int> openPorts; public ObservableCollection<int> OpenPorts { get => openPorts; set { SetProperty(ref openPorts, value); } } public NetScanResult() { OpenPorts = new ObservableCollection<int>(); } } 最后我有了一个扫描逻辑： [RelayCommand] public async void NetScan2Start() { try { int[] ports = { 22, 80, 443, 554, 3389, 8000, 37777 }; int timeoutMs = 2500; var stopwatch = new Stopwatch(); stopwatch.Start(); var netScanResults = await NetUtility.ScanNetwork2_Prepare(NetScanIpRangeBegin, NetScanIpRangeEnd, NetScanNetmaskSelected, ports, timeoutMs); NetScanResults = new ObservableCollection<NetScanResult>(netScanResults); var tasks = new List<Task>(); foreach (var netScanResult in NetScanResults) { foreach (var port in ports) { NetScanResult tempResult = netScanResult; int tempPort = port; var task = ScanPortAsync(tempResult, tempPort, timeoutMs); tasks.Add(task); } } await Task.WhenAll(tasks.ToArray()); stopwatch.Stop(); MessageBox.Show($"Scan finished in {stopwatch.ElapsedMilliseconds}ms"); } catch (Exception ex) { ShowInvalidData(ex.Message); return; } } private async Task ScanPortAsync(NetScanResult result, int port, int timeoutMs) { try { Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp); var connectResult = socket.BeginConnect(result.IpAddress, port, null, null); await Task.Run(() => { connectResult.AsyncWaitHandle.WaitOne(timeoutMs, true); }); if (socket.Connected) { socket.EndConnect(connectResult); Application.Current.Dispatcher.Invoke(() => { result.OpenPorts.Add(port); }); Debug.WriteLine($"{result.IpAddress}:{port} - open."); } socket.Close(); } catch (Exception ex) { Debug.WriteLine($" Exception happened =( - {ex.Message}"); } } 我开始很顺利，但一段时间后用户界面仍然冻结，我不明白为什么。当所有扫描线程完成后，它就会解冻。我错过了什么？我没有从你的代码中看出你为什么使用ObservableCollection。您无需对任何地方的这些集合进行任何更改。你完全形成它们，然后才将它们归还。在我看来，这里很有可能使用“只读”集合。我也认为不需要使用 Dispatcher 或其他细微差别来使用可变属性。扫描结果被分配给一些难以理解的东西 - 它实际上被发送到垃圾箱。同步和异步代码以一种难以想象的方式混合在一起。我建议您从根本上改变执行任务的方法。看一下这个示例 - 由于您没有显示与实现相关的所有代码，因此该示例基于猜测，可能并不完全准确： public class NetScanResult : ObservableObject { public IPAddress IpAddress { get; } public IReadOnlyList<int> OpenPorts { get; } public NetScanResult(IPAddress ipAddress, IEnumerable<int> openPorts) { IpAddress = ipAddress; OpenPorts = Array.AsReadOnly(openPorts?.ToArray() ?? Array.Empty<int>()); } } private async Task<int> ScanPortAsync(/*NetScanResult result,*/ IPAddress ipAddress, int port, int timeoutMs) => await Task.Run(() => { try { Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp); var connectResult = socket.BeginConnect(/*result.IpAddress,*/ipAddress, port, null, null); //await Task.Run(() => { connectResult.AsyncWaitHandle.WaitOne(timeoutMs, true); }); connectResult.AsyncWaitHandle.WaitOne(timeoutMs, true); if (socket.Connected) { socket.EndConnect(connectResult); //Application.Current.Dispatcher.Invoke(() => //{ // result.OpenPorts.Add(port); //}); Debug.WriteLine($"{/*result.IpAddress*/ ipAddress}:{port} - open."); } socket.Close(); return port; } catch (Exception ex) { Debug.WriteLine($" Exception happened =( - {ex.Message}"); return -1; } }); [RelayCommand] public async void NetScan2Start() => await Task.Run(async () => { try { int[] ports = { 22, 80, 443, 554, 3389, 8000, 37777 }; int timeoutMs = 2500; var stopwatch = new Stopwatch(); stopwatch.Start(); // I would change the method to return IP addresses. /*var netScanResults*/ IList<IPAddress> addresses = await NetUtility.ScanNetwork2_Prepare(NetScanIpRangeBegin, NetScanIpRangeEnd, NetScanNetmaskSelected, ports, timeoutMs); //NetScanResults = new ObservableCollection<NetScanResult>(netScanResults); //var tasks = new List<Task>(); var netScanTasks = new Task<NetScanResult>[addresses.Count]; //foreach (var netScanResult in NetScanResults) for (int i = 0; i < addresses.Count; i++) { var portsTasks = new Task<int>[ports.Length]; IPAddress tempAddress = addresses[i]; //foreach (var port in ports) for (int j = 0; j < ports.Length; j++) { //NetScanResult tempResult = netScanResult; int tempPort = ports[j]; /*var task*/ portsTasks[j] = ScanPortAsync(/*tempResult,*/ tempAddress, tempPort, timeoutMs); //tasks.Add(task); } netScanTasks[i] = CreateResult(); async Task<NetScanResult> CreateResult() { await Task.WhenAll(portsTasks); List<int> aports = new List<int>(ports.Length); foreach (var task in portsTasks) { int port = task.Result; if (port > 0) { aports.Add(port); } } return new NetScanResult(tempAddress, aports); }; } await Task.WhenAll(netScanTasks); NetScanResults = netScanTasks.Select(task => task.Result).ToArray(); stopwatch.Stop(); MessageBox.Show($"Scan finished in {stopwatch.ElapsedMilliseconds}ms"); } catch (Exception ex) { ShowInvalidData(ex.Message); return; } });

c# wpf multithreading sockets task

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c# api post async-await task

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引用参数和异步任务

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