C# 被动。主体使onNext等待上一个onNext操作
我正在尝试实现observable,等待C# 被动。主体使onNext等待上一个onNext操作,c#,winforms,async-await,system.reactive,rx.net,C#,Winforms,Async Await,System.reactive,Rx.net,我正在尝试实现observable,等待onNext操作完成,然后再继续执行下一个操作。我发现工作的唯一方法是使用信号量lim。无需使用信号量lim,Reactive是否有办法做到这一点?我找不到 SemaphoreSlim _semaphoreSlim = new SemaphoreSlim(1,1); subject.Window(() => subject.Throttle(TimeSpan.FromMilliseconds(500))) .Select
onNext
操作完成,然后再继续执行下一个操作。我发现工作的唯一方法是使用信号量lim
。无需使用信号量lim
,Reactive是否有办法做到这一点?我找不到
SemaphoreSlim _semaphoreSlim = new SemaphoreSlim(1,1);
subject.Window(() => subject.Throttle(TimeSpan.FromMilliseconds(500)))
.SelectMany(c => c.ToList())
.Subscribe(async x =>
{
await _semaphoreSlim.WaitAsync();
try
{
//await Async code here
}
finally
{
_semaphoreSlim.Release();
}
});
首先,我创建了一个示例
Media\u Load\u Async
,模拟您正在做的事情
static int max = 5;
static Random random = new Random();
static TimeSpan[] delays = Enumerable.Range(0, max).Select(x => TimeSpan.FromSeconds(random.Next(5) + 2)).ToArray();
async Task<Unit> Media_Load_Async(int index, TimeSpan delay)
{
Console.WriteLine($"Start {index} - {delay}");
await Task.Delay(delay);
Console.WriteLine($"End {index}");
return Unit.Default;
}
如果我输入你的SemaporeSlim
代码,我会得到你想要的:
SemaphoreSlim _semaphoreSlim = new SemaphoreSlim(1, 1);
Observable
.Range(0, max)
.Subscribe(async x =>
{
await _semaphoreSlim.WaitAsync();
try
{
await Media_Load_Async(x, delays[x]);
}
finally
{
_semaphoreSlim.Release();
}
});
接下来,如果我将对Media\u Load\u Async
的调用移动到查询本身内部,那么我将回到原始问题:
Observable
.Range(0, max)
.SelectMany(x => Observable.FromAsync(() => Media_Load_Async(x, delays[x])))
.Subscribe();
但是如果我将SelectMany
更改为Select
/Concat
对,那么我就可以在没有信号量lim的情况下得到您想要的:
Observable
.Range(0, max)
.Select(x => Observable.FromAsync(() => Media_Load_Async(x, delays[x])))
.Concat()
.Subscribe();
看看这些:。核心接收接口是同步的。已实现具有异步接口的Rx的替代版本(),但是。我正在尝试您的解决方案,但不幸的是,Observable.FromAsync给我带来了麻烦,因为它在另一个SynchronizationContext上被调用。我需要在UI线程上进行观察。因此,您提出的解决方案进行了一些调整。我将在这里留下代码,以防:subject.Window(()=>subject.Throttle(TimeSpan.frommissions(500)).SelectMany(c=>c.ToList()).Select(c=>(reloadMap:c.Any(z=>z.reloadMap),c.LastOrDefault(z=>z.rowIndex.HasValue).rowIndex)).Select(x=>Observable.fromsync(()=>(Task)this.Invoke)(新的MethodInvoker(()=>x.rowIndex.HasValue?媒体加载异步(x.rowIndex.Value):Task.CompletedTask))).Concat().Subscribe();
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End 0
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Observable
.Range(0, max)
.SelectMany(x => Observable.FromAsync(() => Media_Load_Async(x, delays[x])))
.Subscribe();
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Observable
.Range(0, max)
.Select(x => Observable.FromAsync(() => Media_Load_Async(x, delays[x])))
.Concat()
.Subscribe();
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