/// <summary>
/// Task 生成 Observable，使用 ToObservable。
/// 这个写法很简单，而且执行时间是耗时最长的 Task 时间，跟 AsyncAwaitGenerate 不一样
/// </summary>
/// <param name="amout"></param>
/// <returns></returns>
public static IObservable <int> TaskToObservable(int amout)
{
var o1 = PrimeGenerator.GenerateAsync(5).ToObservable();
var o2 = PrimeGenerator.GenerateAsync(5).ToObservable();
return(o1.Concat(o2) // 先用 Concat 连接两个集合
.SelectMany(primes => primes)); // 再用 SelectMany 投影每个值
}
/// <summary>
/// AsyncAwait 模式生成Observable
/// 执行时间等于所有task总和
/// </summary>
/// <param name="amout"></param>
/// <returns></returns>
public static IObservable <int> AsyncAwaitGenerate(int amout)
{
return(Observable.Create <int>(async o =>
{
var primes1 = await PrimeGenerator.GenerateAsync(5);
foreach (var prime in primes1)
{
o.OnNext(prime);
}
var primes2 = await PrimeGenerator.GenerateAsync(5);
foreach (var prime in primes2)
{
o.OnNext(prime);
}
o.OnCompleted();
}));
}
/// <summary>
/// 周期性地生成 Observable，均匀时间间隔
/// </summary>
/// <returns></returns>
public static IObservable <int> CreateByInterval()
{
return(Observable.Interval(TimeSpan.FromSeconds(2))
.SelectMany(_ => PrimeGenerator.GenerateAsync(3))
.SelectMany(primes => primes));
}