我有一个C#控制台应用程序,除此之外,我可以通过TCP套接字连接获得输入。当我通过套接字通过接收功能接收输入时,如何切换到主线程?
在WPF中类似于这样的东西:
public void TaskDispatcher()
{
if (DispatcherObjectForTaskDispatcher.Thread != System.Threading.Thread.CurrentThread)
DispatcherObjectForTaskDispatcher.Invoke(new TaskDispatcherDelegate(TaskDispatcher));
else
{
// Do some thing in the UI thread
}
}
答案 0 :(得分:1)
只需使用Producer-Consumer模式,如下面的工作示例所示。从其他线程入队作业,让主线程处理作业队列中的排队作业。
我使用计时器线程和用户输入线程来模拟生成作业的2个线程。您可以实现TCP事件,以便在作业队列中排队作业。您应该将任何相关对象作为参数存储在作业中,以便以后处理。您还必须定义一个要由作业调用的函数,该函数将在主线程中运行。
这里使用的主要线程只是为了使作业出列并处理它们,但如果你稍微改进一下这个代码就可以使用任何其他线程。
您甚至可以实现多线程处理,其中更多处理线程从同一作业队列中出列。请注意,这会带来您可能需要处理的新并发问题。这是在您的应用程序中获得更多处理能力的缺点。某些场景适用于多线程处理(例如视频/图像处理),而其他场景则不适用。
以下代码是使用 Visual Studio 2017 , DotNET 4.6.1 ,控制台应用程序项目编写的完整工作示例。只需复制,粘贴并点击F5。
using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Threading;
// Compiled and tested in: Visual Studio 2017, DotNET 4.6.1
namespace MyNamespace
{
public class Program
{
public static void Main(string[] args)
{
MyApplication app = new MyApplication();
app.Run();
}
}
public class MyApplication
{
private BlockingCollection<Job> JobQueue = new BlockingCollection<Job>();
private CancellationTokenSource JobCancellationTokenSource = new CancellationTokenSource();
private CancellationToken JobCancellationToken;
private Timer Timer;
private Thread UserInputThread;
public void Run()
{
// Give a name to the main thread:
Thread.CurrentThread.Name = "Main";
// Fires a Timer thread:
Timer = new Timer(new TimerCallback(TimerCallback), null, 1000, 2000);
// Fires a thread to read user inputs:
UserInputThread = new Thread(new ThreadStart(ReadUserInputs))
{
Name = "UserInputs",
IsBackground = true
};
UserInputThread.Start();
// Prepares a token to cancel the job queue:
JobCancellationToken = JobCancellationTokenSource.Token;
// Start processing jobs:
ProcessJobs();
// Clean up:
JobQueue.Dispose();
Timer.Dispose();
UserInputThread.Abort();
Console.WriteLine("Done.");
}
private void ProcessJobs()
{
try
{
// Checks if the blocking collection is still up for dequeueing:
while (!JobQueue.IsCompleted)
{
// The following line blocks the thread until a job is available or throws an exception in case the token is cancelled:
JobQueue.Take(JobCancellationToken).Run();
}
}
catch { }
}
private void ReadUserInputs()
{
// User input thread is running here.
ConsoleKey key = ConsoleKey.Enter;
// Reads user inputs and queue them for processing until the escape key is pressed:
while ((key = Console.ReadKey(true).Key) != ConsoleKey.Escape)
{
Job userInputJob = new Job("UserInput", this, new Action<ConsoleKey>(ProcessUserInputs), key);
JobQueue.Add(userInputJob);
}
// Stops processing the JobQueue:
JobCancellationTokenSource.Cancel();
}
private void ProcessUserInputs(ConsoleKey key)
{
// Main thread is running here.
Console.WriteLine($"You just typed '{key}'. (Thread: {Thread.CurrentThread.Name})");
}
private void TimerCallback(object param)
{
// Timer thread is running here.
Job job = new Job("TimerJob", this, new Action<string>(ProcessTimer), "A job from timer callback was processed.");
JobQueue.TryAdd(job); // Just enqueues the job for later processing
}
private void ProcessTimer(string message)
{
// Main thread is running here.
Console.WriteLine($"{message} (Thread: {Thread.CurrentThread.Name})");
}
}
/// <summary>
/// The Job class wraps an object's method call, with or without arguments. This method is called later, during the Job execution.
/// </summary>
public class Job
{
public string Name { get; }
private object TargetObject;
private Delegate TargetMethod;
private object[] Arguments;
public Job(string name, object obj, Delegate method, params object[] args)
{
Name = name;
TargetObject = obj;
TargetMethod = method;
Arguments = args;
}
public void Run()
{
try
{
TargetMethod.Method.Invoke(TargetObject, Arguments);
}
catch(Exception ex)
{
Debug.WriteLine($"Unexpected error running job '{Name}': {ex}");
}
}
}
}