如何在返回Task的方法中调用异步方法？

Question

In the SignalR hub I've this:

public class MyHub : Hub
{
    public override Task OnConnected()
    {
        // my async code here
        return base.OnConnected();
    }
}

I want to perform an async code. So I added async keyword like this:

public class MyHub : Hub
{
    public override async Task OnConnected()
    {
        var result = await MyAsyncMethod();
        return base.OnConnected();
    }
}

but return base.OnConnected(); shows this error:

Since MyHub.OnConnected() is an async method that returns Task , a returned keyword must not be followed by an object expression. Did you intend to return Task<T> ?

How can I fix it? thanks.

Answer 1

An async method is converted into a state machine by the compiler. You cannot return that Task here, because the Task returned is generated by the compiler and represents the continuation of this method.

Simply await the base call:

public override async Task OnConnected()
{
    var result = await MyAsyncMethod();
    await base.OnConnected();
}