TaskCompletionSource何时应 使用？

当仅基于事件的API可用时（例如Windows Phone 8套接字），我主要使用它：

public Task<Args> SomeApiWrapper(){    TaskCompletionSource<Args> tcs = new TaskCompletionSource<Args>();    var obj = new SomeApi();    // will get raised, when the work is done    obj.Done += (args) =>     {        // this will notify the caller         // of the SomeApiWrapper that         // the task just completed        tcs.SetResult(args);    }    // start the work    obj.Do();    return tcs.Task;}

因此，与C＃5

async