以下代码使用 Task 异步接收,并在控制台中显示接收结果:
private void ReceiveMessage()
{
Task.Run(async() =>
{
using(var udpClient = new UdpClient(15000))
{
while(true)
{
var receivedResult = await udpClient.ReceiveAsync();
Console.Write(Encoding.ASCII.GetString(receivedResult.Buffer));
}
}
});
}
我想学习如何使用 async/await 函数,所以我想知道如何使用 async/await 异步制作函数 ReceiveMessage() ?
如果您希望整个方法可以等待,只需将其更改为:
private async Task ReceiveMessage()
{
using(var udpClient = new UdpClient(15000))
{
while(true)
{
var receivedResult = await udpClient.ReceiveAsync();
Console.Write(Encoding.ASCII.GetString(receivedResult.Buffer));
}
}
}
您不再需要Task.Run()
,这将使用线程。不需要该线程。现在,该方法在await
ReceiveAsync()
时返回到调用方。
当ReceiveAsync()
完成后,该方法(最终)在Console.WriteLine()
恢复。
它被触发并忘记,则您拥有的代码是有效的,在单独的线程上侦听。如果您不想这样做,我会删除Task.Run
并确保在您的方法中返回一个Task
,如下所示:
private async Task ReceiveMessage()
{
using (var udpClient = new UdpClient(15000))
{
while (true)
{
var receivedResult = await udpClient.ReceiveAsync();
Console.Write(Encoding.ASCII.GetString(receivedResult.Buffer));
}
}
}
只需向函数添加另一个 async/await:
private async void receiveMessage()
{
await Task.Run(async() =>
{
using(var udpClient = new UdpClient(15000))
{
while(true)
{
var receivedResult = await udpClient.ReceiveAsync();
Console.Write(Encoding.ASCII.GetString(receivedResult.Buffer));
}
}
});
}
如果要编写可等待的方法,请返回一个任务:
private Task foo(){
Task doStuff = new Task(() => {});
doStuff.Start();
return doStuff;
};
//Another method
private async void bar()
{
await foo();
}
更新:如下所述,您实际上不需要在线程池内的线程上执行该任务。没有错,而是没用。为了更好地使用,您可以使用:
private async void receiveMessage()
{
using(var udpClient = new UdpClient(15000))
{
while(true)
{
var receivedResult = await udpClient.ReceiveAsync();
Console.Write(Encoding.ASCII.GetString(receivedResult.Buffer));
}
}
}