如何使函数阻塞直到它有数据要在C#中返回

如何制作一个自定义函数,该函数返回输出并阻塞直到输出可用?我在想类似Console.ReadLine()的东西.像这样:

var resp = Output(); //blocks until output is sent.
...
//returns a string once SendOutput is called and hands over the string.
public static string Output() { /* what goes here? */ }
//Is this function even needed? Can I just fire Output somehow?
private static string SendOutput(string msg) { /* what goes here? */ }
...
//Calls sendoutput with the string to send.
SendOutput(msg);

基本上,我正在制作一个被监听的监听器,直到它获取数据为止(就像调用console.readline一样),并且我需要内部代码来制作该监听器.

解决方法:

您想要的是在其他一些工作完成时发出阻塞方法调用的信号. ManualResetEvent是实现此行为的好方法.没有循环,并且一旦工作线程表明已完成,返回实际上是瞬时的.

class Program
{
    static void Main(string[] args)
    {
        Blocker b = new Blocker();
        Console.WriteLine(b.WaitForResult());
    }
}

public class Blocker
{
    private const int TIMEOUT_MILLISECONDS = 5000;
    private ManualResetEvent manualResetEvent;

    private string output;

    public string WaitForResult()
    {
        // create an event which we can block on until signalled
        manualResetEvent = new ManualResetEvent(false);

        // start work in a new thread
        Thread t = new Thread(DoWork);
        t.Start();

        // block until either the DoWork method signals it is completed, or we timeout (timeout is optional)
        if (!manualResetEvent.WaitOne(TIMEOUT_MILLISECONDS))
            throw new TimeoutException();

        return output;
    }

    private void DoWork()
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++)
        {
            sb.AppendFormat("{0}.", i);
        }
        output = sb.ToString();

        // worker thread is done, we can let the WaitForResult method exit now
        manualResetEvent.Set();
    }
}
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