c# Windows Phone 8.1 GetOutputStreamAsync(..)第一次使用后阻塞

本文关键字：第一次 Phone Windows GetOutputStreamAsync | 更新日期: 2023-09-27 18:13:46

我目前正在尝试创建一个非常基本的测试应用程序，它应该:

1)在端口"1234"上广播"sometext"
2)等待答案
3)返回所有答案

虽然下面发布的解决方案第一次工作得很好，但每个后续调用都永远阻塞在:
stream = await socket.GetOutputStreamAsync(…)

到目前为止，我尝试了所有可能的清理方法(因为这是我认为失败的地方)，甚至使用(…)语句将所有内容包装在中。

模拟器和使用Windows Phone 8.1的硬件设备都出现了这个问题

提前感谢!

启动"discovery"的代码:

private void Button_Click(object sender, RoutedEventArgs e)
{
    PluginUDP pudp = new PluginUDP();
    var task = pudp.scan("asf");
    task.Wait();
    foreach (string s in task.Result)
        output.Text += s + "'r'n";            
}

"discovery"本身的代码:

using System;
using Windows.Networking;
using Windows.Networking.Sockets;
using Windows.Storage.Streams;
using System.Text;
using System.IO;
using System.Threading.Tasks;
using System.Collections.Concurrent;
using namespace whatever
{
    public class PluginUDP
    {
        private static readonly HostName BroadcastAddress = new HostName("255.255.255.255");
        private static readonly string BroadcastPort = "1234";
        private static readonly byte[] data = Encoding.UTF8.GetBytes("00wlan-ping00");
        ConcurrentBag<string> receivers;        
        public async System.Threading.Tasks.Task<string[]> scan(string options)
        {
            receivers = new ConcurrentBag<string>();
            receivers.Add("ok");
            DatagramSocket socket = null;
            IOutputStream stream = null;
            DataWriter writer = null;
            try
            {
                socket = new DatagramSocket();                
                socket.MessageReceived += MessageReceived;
                await socket.BindServiceNameAsync("");
                stream = await socket.GetOutputStreamAsync(BroadcastAddress, BroadcastPort);
                writer = new DataWriter(stream);               
                writer.WriteBytes(data);
                await writer.StoreAsync();
                Task.Delay(1000).Wait();                
            }
            catch (Exception exception)
            {
                receivers.Add(exception.Message);
            }
            finally
            {
                if (writer != null)
                {
                    writer.DetachStream();
                    writer.Dispose();
                }
                if(stream != null)
                    stream.Dispose();
                if(socket != null)
                    socket.Dispose();
            }
            return receivers.ToArray(); ;
        }
        private async void MessageReceived(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs args)
        {
            try
            {
                var result = args.GetDataStream();
                var resultStream = result.AsStreamForRead(1024);
                using (var reader = new StreamReader(resultStream))
                {
                    var text = await reader.ReadToEndAsync();
                    if (text.Contains("pong"))
                    {
                        receivers.Add(args.RemoteAddress.ToString());
                    }
                }
            }
            catch (Exception exception)
            {
                receivers.Add("ERRCV");
            }
        }
    }
}

c# Windows Phone 8.1 GetOutputStreamAsync(..)第一次使用后阻塞

你的问题从这里开始:

task.Wait();

你正在阻塞异步代码，这会导致死锁

你想:

private async void Button_Click(object sender, RoutedEventArgs e)
{
    PluginUDP pudp = new PluginUDP();
    string[] result = await pudp.scan("asf");
    foreach (string s in result)
        output.Text += s + "'r'n";            
}

你还可以这样做:

await Task.Delay(1000);

代替:

Task.Delay(1000).Wait();

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