UniRx官方入门文档

mac2022-06-30  24

UniRx 官方文档翻译

UniRx官方入门文档UniRx入门系列一UniRx入门系列二UniRx入门系列三UniRx入门系列四UniRx入门系列五

UniRx 基于Unity的响应式编程框架

什么是UniRx?


UniRx(Unity的响应式编程框架)是.Net响应式编程框架的重新实现版本。官方的Rx的实现方式是非常棒的。但是,在Unity中使用会有一些问题;在IOS的IL2CPP中有兼容性的问题。UniRx修复这些问题,并针对Unity添加了一些特别的工具。支持的平台包括PC/Mac/Android/iOS/WebGL/WindowsStore/等等。

UniRx可在Asset Store(免费)中下载: http://u3d.as/content/neuecc/uni-rx-reactive-extensions-for-unity/7tT

博客信息更新:https://medium.com/@neuecc

Unity Forums 在线支持,有问题随时向我提问:http://forum.unity3d.com/threads/248535-UniRx-Reactive-Extensions-for-Unity

发现说明: UniRx/releases

UniRx 作为核心库+平台适配器(MainThreadScheduler/FromCoroutinue/etf)+框架(ObservableTriggers/ReactiveProperty/etc)

注意:async/await 集成(UniRx.Async)被分离到Cysharp/UniTask 7.0之后的版本

为什么使用Rx?


通常,在Unity对网络操作要求使用WWW和Coroutine.但是出于以下几点原因(或者其它原因)使用协程来进行异步操作并不顺手:

1.虽然协程的返回类型必须是IEnumerator,但是协程不能返回任何值。 2.因为yield return 语句不能被try-catch结构体包裹,协程中不能处理异常。

这种缺乏可组合性导致程序的紧耦合,往往造成IEnumators中逻辑过于复杂。

Rx可以解决异步调用的“伤痛”,Rx 是一个使用可观察集合和LINQ风格查询运算符组合成的基于异步和基于事件的可编程库。

游戏循环(every Update,OnCollisionEnter),传感器数据(Kinect,Leap Motion,VR Input 等等)这些类型的事件。Rx将事件表示为响应式序列。通过使用LINQ查询运算符,Rx变得容易组合且支持基于时间的操作。

Unity通常是单线程的,但是UniRx促进了多线程joins、cancel 访问GameObject,等等。

UniRx为UGUI提供了UI编程。所有的UI事件(clicked,valuechanged,等)均可以被转化为UniRx的事件流。

Unity 在2017之后支持C# 中的astnc/await。UniRx 为Unity提供了更轻量、强大的async/await集成。请看: Cysharp/UniTask.

介绍


非常棒的介绍Rx的文章:The introduction to Reactive Programming you’ve been missing.

以下代码使用UniRx实现了文章中的双击检测事例:

var clickStream=Observable.EveryUpdate() .Where(_=>Input.GetMouseButtonDown(0)); clickStream.Buffer(clickStream.Throttle(TimeSpan.FromMilliseconds(250))) .Where(xs => xs.Count >= 2) .Subscribe(xs => Debug.Log("DoubleClick Detected! Count:" + xs.Count));

本事例演示了以下功能(仅仅使用5行代码):

游戏循环(Update)作为事件流可组合事件流合并自身流易于处理基于时间的操作

网络操作


使用ObservableWWW 进行一步网络操作。它的Get/Post函数返回可订阅的IObservables.

ObservableWWW.Get("http://google.co.jp/") .Subscribe( x=Debug.Log(x.Substring(0,100)), ex=Debug.LogExecption(ex) );

Rx是可组合也是可以取消的,你可以使用LINQ 查询表达式:

var query=from google in ObservableWWW.Get("http://google.com/") from bing in ObservableWWW.Get("http://bing.com/") from unknow in ObservableWWW(goole+bing) select new {google,bing,unknow}; var cancel=query.Subscribe(x=>Debug.Log(x)); cancel.Dispose();

使用Observable.WhenAll 执行并行请求(parallel):

var parallel=Observable.WhenAll( ObservableWWW.Get("http://google.com/"), ObservableWWW.Get("http://bing.com/"), ObservableWWW.Get("http://unity3d.com/") ); parallel.Subscribe(xs=>{ Debug.Log(xs[0].Substring(0,100));// google Debug.Log(xs[1].Substring(0,100));// bing Debug.Log(xs[2].Substring(0,100));// unity });

提供进度信息:

// notifier for progress use ScheduledNotifier or new Progress<float>(/* action */) var progressNotifier=new ScheduledNotifier<float>(); // pass notifier to WWW.Get/Post progressNotifier.Subscribe(x=>Debug.Log(x));

错误处理:

// If WWW has .error, ObservableWWW throws WWWErrorException to onError pipeline. // WWWErrorException has RawErrorMessage, HasResponse, StatusCode, ResponseHeaders ObservableWWW.Get("http://www.google.com/404") .CatchIgnore((WWWErrorException ex) => { Debug.Log(ex.RawErrorMessage); if (ex.HasResponse) { Debug.Log(ex.StatusCode); } foreach (var item in ex.ResponseHeaders) { Debug.Log(item.Key + ":" + item.Value); } }) .Subscribe();

使用IEnumators (Coroutines)


IEnumator(Coroutine)是Unity的基本异步工具,UniRx集成了协程和IObservables,你可以在协程中写异步代码,并使用UniRx编排他们。这是控制异步流最好的方式。

// two coroutines IEnumerator AsyncA() { Debug.Log("a start"); yield return new WaitForSeconds(1); Debug.Log("a end"); } IEnumerator AsyncB() { Debug.Log("b start"); yield return new WaitForEndOfFrame(); Debug.Log("b end"); } // main code // Observable.FromCoroutine converts IEnumerator to Observable<Unit>. // You can also use the shorthand, AsyncA().ToObservable() // after AsyncA completes, run AsyncB as a continuous routine. // UniRx expands SelectMany(IEnumerator) as SelectMany(IEnumerator.ToObservable()) var cancel = Observable.FromCoroutine(AsyncA) .SelectMany(AsyncB) .Subscribe(); // you can stop a coroutine by calling your subscription's Dispose. cancel.Dispose();

在Unity5.3中,你可以使用ToYieldInstruction将Observable转化为Coroutine:

IEnumerator TestNewCustomYieldInstruction() { // wait Rx Observable. yield return Observable.Timer(TimeSpan.FromSeconds(1)).ToYieldInstruction(); // you can change the scheduler(this is ignore Time.scale) yield return Observable.Timer(TimeSpan.FromSeconds(1), Scheduler.MainThreadIgnoreTimeScale).ToYieldInstruction(); // get return value from ObservableYieldInstruction var o = ObservableWWW.Get("http://unity3d.com/").ToYieldInstruction(throwOnError: false); yield return o; if (o.HasError) { Debug.Log(o.Error.ToString()); } if (o.HasResult) { Debug.Log(o.Result); } // other sample(wait until transform.position.y >= 100) yield return this.transform.ObserveEveryValueChanged(x => x.position).FirstOrDefault(p => p.y >= 100).ToYieldInstruction(); }

通常情况下,当我们想要协程返回一个值时,我们必须使用回调。Observable.FromCoroutine 可以将协程转化为可取消的IObservable[T]。

public static IObservable<string> GetWWW(string url) { // convert coroutine to IObservable return Observable.FromCoroutine<string>((observer, cancellationToken) => GetWWWCore(url, observer, cancellationToken)); } // IObserver is a callback publisher // Note: IObserver's basic scheme is "OnNext* (OnError | Oncompleted)?" static IEnumerator GetWWWCore(string url, IObserver<string> observer, CancellationToken cancellationToken) { var www = new UnityEngine.WWW(url); while (!www.isDone && !cancellationToken.IsCancellationRequested) { yield return null; } if (cancellationToken.IsCancellationRequested) yield break; if (www.error != null) { observer.OnError(new Exception(www.error)); } else { observer.OnNext(www.text); observer.OnCompleted(); // IObserver needs OnCompleted after OnNext! } }

这还有更多的示例,下方展示多个OnNext的形式:

public static IObservable<float> ToObservable(this UnityEngine.AsyncOperation asyncOperation) { if (asyncOperation == null) throw new ArgumentNullException("asyncOperation"); return Observable.FromCoroutine<float>((observer, cancellationToken) => RunAsyncOperation(asyncOperation, observer, cancellationToken)); } static IEnumerator RunAsyncOperation(UnityEngine.AsyncOperation asyncOperation, IObserver<float> observer, CancellationToken cancellationToken) { while (!asyncOperation.isDone && !cancellationToken.IsCancellationRequested) { observer.OnNext(asyncOperation.progress); yield return null; } if (!cancellationToken.IsCancellationRequested) { observer.OnNext(asyncOperation.progress); // push 100% observer.OnCompleted(); } } // usecase Application.LoadLevelAsync("testscene") .ToObservable() .Do(x => Debug.Log(x)) // output progress .Last() // last sequence is load completed .Subscribe();

多线程的使用


// Observable.Start is start factory methods on specified scheduler // default is on ThreadPool var heavyMethod = Observable.Start(() => { // heavy method... System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1)); return 10; }); var heavyMethod2 = Observable.Start(() => { // heavy method... System.Threading.Thread.Sleep(TimeSpan.FromSeconds(3)); return 10; }); // Join and await two other thread values Observable.WhenAll(heavyMethod, heavyMethod2) .ObserveOnMainThread() // return to main thread .Subscribe(xs => { // Unity can't touch GameObject from other thread // but use ObserveOnMainThread, you can touch GameObject naturally. (GameObject.Find("myGuiText")).guiText.text = xs[0] + ":" + xs[1]; });

DefaultScheduler(默认调度器)


UniRx默认是基于时间操作的(Interval、Timer、Buffer(timeSpan)等等),使用Scheduler.MainThread作为它们的调度器。UniRx中的大多数运算符(Observable.Start除外)都是在单个线程上执行的;因此不需要ObserverOn,并且可以忽略线程安全问题。虽然和标准 .NET 中的Rx实现不同,但是这更符合Unity的环境。 Scheduler.Mainthread的执行受Time.timeScale的影响,如果你想要在执行时忽略TimeScale,你可以使用Scheduler.MainThreadIgnoreTimeScale代替。

MonoBehaviour triggers


UniRx使用UniRx.Triggers处理MonoBehaviour事件:

using UniRx; using UniRx.Triggers; // need UniRx.Triggers namespace public class MyComponent : MonoBehaviour { void Start() { // Get the plain object var cube = GameObject.CreatePrimitive(PrimitiveType.Cube); // Add ObservableXxxTrigger for handle MonoBehaviour's event as Observable cube.AddComponent<ObservableUpdateTrigger>() .UpdateAsObservable() .SampleFrame(30) .Subscribe(x => Debug.Log("cube"), () => Debug.Log("destroy")); // destroy after 3 second:) GameObject.Destroy(cube, 3f); } }

支持的triggers如列表所示:UniRx.wiki#UniRx.Triggers

通过直接订阅Component/GameObject上的扩展方法返回的Observables(可观察对象),可以更轻松的处理事件,这些方法被自动注入到ObservableTrigger中(除了ObservableEventTrigger和ObservableStateMachineTrigger):

using UniRx; using UniRx.Triggers; public class DragAndDropOnce:MonoBehaviour{ void Start(){ this.OnMouseDownAsObservable() .SelectMany(_=>this.UpdateAsObservable()) .TakeUntil(this.OnMouseUpAsObservable()) .Select(_=>Input.mousePosition) .Subscribe(x=>Debug.Log(x)); } }

之前版本中UniRx提供了ObservableMonoBehaiour.新版本中以不再对其提供支持,请使用UniRx.Triggers代替。

创建自定义Triggers

将Unity事件转化为Observable(可观察对象)是处理Unity事件最好的方式。如果UniRx提供的标准的triggers不够使用的话,你可以自定义triggers.为了演示,下方提供了一个基于UGUI的LongTap(长按)触发演示:

public class ObservableLongPointerDownTrigger : ObservableTriggerBase, IPointerDownHandler, IPointerUpHandler{ public float IntervalSecond=1f; Subject<Unit> onLongPointerDown; float> raiseTime; void Update(){ if (raiseTime!=null&&raiseTime<=Time.realtimeSinceStartup){ if (onLongPointerDown!=null)onLongPointerDown.OnNext(Unit.Default); raiseTime=null; } } void IPointerDownHandler.OnPointerDown(PointerEventData eventData) { raiseTime = Time.realtimeSinceStartup + IntervalSecond; } void IPointerUpHandler.OnPointerUp(PointerEventData eventData) { raiseTime = null; } public IObservable<Unit> OnLongPointerDownAsObservable() { return onLongPointerDown ?? (onLongPointerDown = new Subject<Unit>()); } protected override void RaiseOnCompletedOnDestroy() { if (onLongPointerDown != null) { onLongPointerDown.OnCompleted(); } } }

它的使用像标准triggers一样简单:

var trigger = button.AddComponent<ObservableLongPointerDownTrigger>(); trigger.OnLongPointerDownAsObservable().Subscribe();

Observable 生命周期管理


什么时候调用OnCompleted? 使用UniRx时,必须考虑订阅的生命周期管理。当与GameObject对象相连的游戏对象被销毁时,ObservableTriggers会调用OnCompleted.其它的静态生成器方法(Observable.Timer、Observable.EveryUpdate…等等,并不会自动停止,他们的订阅需要被手动管理。

Rx提供了一些辅助方法,比如,IDisposable.AddTo运行你一次释放多个订阅:

// CompositeDisposable is similar with List<IDisposable>, manage multiple IDisposable CompositeDisposable disposables = new CompositeDisposable(); // field void Start() { Observable.EveryUpdate().Subscribe(x => Debug.Log(x)).AddTo(disposables); } void OnTriggerEnter(Collider other) { // .Clear() => Dispose is called for all inner disposables, and the list is cleared. // .Dispose() => Dispose is called for all inner disposables, and Dispose is called immediately after additional Adds. disposables.Clear(); }

如果你想在GameObject被销毁时自动释放,你可以使用AddTo(GameObject/Component):

void Start(){ Observable.IntervalFrame(30).Subscribe(x=Debug.Log(x)).AddTo(this); }

AddTo可以促进流的自动释放,如果你需要在管道中队OnCompleted进行特殊处理,那么你可以使用TakeWhile、TakeUntil、TakeUntilDestroy和TakeUntilDisable代替:

Observable.IntervalFrame(30).TakeUntilDisable(this) .Subscribe(x => Debug.Log(x), () => Debug.Log("completed!"));

当你处理事件时,Repeat是一种重要但危险的方法,它可能会造成程序的无线循环,因此,请谨慎使用它:

using UniRx; using UniRx.Triggers; public class DangerousDragAndDrop:MonoBehaviour{ void Start(){ this.gameObject.OnMouseDownAsObservable() .SelectMany(_=>this.gameObject.UpdateAsObservable()) .TakeUtil(this.gameObject.OnMouseUpAsObservable()) .Select(_=>Input.mousePosition) .Repeat() .Subscribe(x=>Debug.Log(x)); } }

UniRx另外提供了一种安全使用Repeat的方法。RepeatSafe: 如果重复调用OnComplete,Repeat将会停止。RepeatUntilDestroy(gameObject/component), RepeatUntilDisable(gameObject/component)允许在目标对象被销毁时停止。

this.gameObject.OnMouseDownAsObservable() .SelectMany(_ => this.gameObject.UpdateAsObservable()) .TakeUntil(this.gameObject.OnMouseUpAsObservable()) .Select(_ => Input.mousePosition) .RepeatUntilDestroy(this) // safety way .Subscribe(x => Debug.Log(x));

UniRx确保hot Observable(FromEvent/Subject/ReactiveProperty/UnityUI.AsObservable…, 类似事件)可以持续的处理异常。什么意思?如果在Subscribe中订阅,这不分离事件。

button.OnClickAsObservable().Subscribe(_ => { // If throws error in inner subscribe, but doesn't detached OnClick event. ObservableWWW.Get("htttp://error/").Subscribe(x => { Debug.Log(x); }); });

这种行为有时很有用,比如用户事件的处理。

每一个类的实例都提供了一个ObserveEveryValueChanged的方法。这个方法可以每一帧检测某个值发生的变化:

// watch position change this.transform.ObserveEveryValueChanged(x => x.position).Subscribe(x => Debug.Log(x));

这是非常有用的,如果观察的目标是一个GameObject;当GameObject被销毁时,订阅将自动停止并调用OnCompleted.如果观察的对象是一个原生的C#对象,OnCompleted将在GC时被调用。

将Unity回调转化为IObservables(可观察对象)


使用Subject(或者AsyncSubject进行异步操作):

public class LogCallback { public string Condition; public string StackTrace; public UnityEngine.LogType LogType; } public static class LogHelper { static Subject<LogCallback> subject; public static IObservable<LogCallback> LogCallbackAsObservable() { if (subject == null) { subject = new Subject<LogCallback>(); // Publish to Subject in callback UnityEngine.Application.RegisterLogCallback((condition, stackTrace, type) => { subject.OnNext(new LogCallback { Condition = condition, StackTrace = stackTrace, LogType = type }); }); } return subject.AsObservable(); } } // method is separatable and composable LogHelper.LogCallbackAsObservable() .Where(x => x.LogType == LogType.Warning) .Subscribe(); LogHelper.LogCallbackAsObservable() .Where(x => x.LogType == LogType.Error) .Subscribe();

Unity5中,Application.RegisterLogCallback被移除了,转而提供Application.logMessageReceived的支持,因此,我们现在可以简单的使用Observable.FromEvent.

public static IObservable<LogCallback> LogCallbackAsObservable() { return Observable.FromEvent<Application.LogCallback, LogCallback>( h => (condition, stackTrace, type) => h(new LogCallback { Condition = condition, StackTrace = stackTrace, LogType = type }), h => Application.logMessageReceived += h, h => Application.logMessageReceived -= h); }

Stream Logger


// using UniRx.Diagnostics; // logger is threadsafe, define per class with name. static readonly Logger logger = new Logger("Sample11"); // call once at applicationinit public static void ApplicationInitialize() { // Log as Stream, UniRx.Diagnostics.ObservableLogger.Listener is IObservable<LogEntry> // You can subscribe and output to any place. ObservableLogger.Listener.LogToUnityDebug(); // for example, filter only Exception and upload to web. // (make custom sink(IObserver<EventEntry>) is better to use) ObservableLogger.Listener .Where(x => x.LogType == LogType.Exception) .Subscribe(x => { // ObservableWWW.Post("", null).Subscribe(); }); } // Debug is write only DebugBuild. logger.Debug("Debug Message"); // or other logging methods logger.Log("Message"); logger.Exception(new Exception("test exception"));

Debugging


UniRx.Diagnostics命名空间下的Debug运算符便于用于调试。

// needs Diagnostics using using UniRx.Diagnostics; --- // [DebugDump, Normal]OnSubscribe // [DebugDump, Normal]OnNext(1) // [DebugDump, Normal]OnNext(10) // [DebugDump, Normal]OnCompleted() { var subject = new Subject<int>(); subject.Debug("DebugDump, Normal").Subscribe(); subject.OnNext(1); subject.OnNext(10); subject.OnCompleted(); } // [DebugDump, Cancel]OnSubscribe // [DebugDump, Cancel]OnNext(1) // [DebugDump, Cancel]OnCancel { var subject = new Subject<int>(); var d = subject.Debug("DebugDump, Cancel").Subscribe(); subject.OnNext(1); d.Dispose(); } // [DebugDump, Error]OnSubscribe // [DebugDump, Error]OnNext(1) // [DebugDump, Error]OnError(System.Exception) { var subject = new Subject<int>(); subject.Debug("DebugDump, Error").Subscribe(); subject.OnNext(1); subject.OnError(new Exception()); }

在在OnNext,OnError,OnCompleted,OnCancel,OnSubscribe时序上显示序列元素以进行Debug.Log,仅当#if DEBUG时才被启用。

Unity-specific Extra Gems

// Unity's singleton UiThread Queue Scheduler Scheduler.MainThreadScheduler ObserveOnMainThread()/SubscribeOnMainThread() // Global StartCoroutine runner MainThreadDispatcher.StartCoroutine(enumerator) // convert Coroutine to IObservable Observable.FromCoroutine((observer, token) => enumerator(observer, token)); // convert IObservable to Coroutine yield return Observable.Range(1, 10).ToYieldInstruction(); // after Unity 5.3, before can use StartAsCoroutine() // Lifetime hooks Observable.EveryApplicationPause(); Observable.EveryApplicationFocus(); Observable.OnceApplicationQuit();

FrameCount-based timeoperators


UniRx 提供了一些继续帧数的时间运算符

MethodEveryUpdateEevryFixedUpdateEveryEndOfFrameEveryGameObjectUpdateEveryLateUpdateObserveOnMainThreadNextFrameIntervalFrameTimerFrameDelayFrameSampleFrameThrottleFrameThrottleFirstFrameTimeoutFrameDelayFrameSubscriptionFrameIntervalFrameTimeIntervalBatchFrame

例如,一次延时调用:

Observable.TimerFrame(100).Subscribe(_ => Debug.Log("after 100 frame"));

Every* 方法的执行顺序如下:

EveryGameObjectUpdate(in MainThreadDispatcher's Execution Order) -> EveryUpdate -> EveryLateUpdate -> EveryEndOfFrame

如果在MainThreadDispatcher之前调用了调用者,则从同一帧调用EveryGameObjectUpdate.(我建议对MainThreadDispatcher的调用在同一帧中优先于EveryLateUpdate、EveryEndOfFrame),EveryUpdate在下一帧中调用。

MicroCoroutine(微协程)

微协程的优点在于内存高效和执行快速。它的实现是基于Unity blog’s 10000 UPDATE() CALLS,避免了托管内存-非托管内存的开销,以致迭代速度提升了10倍。微协程自动用于基于帧数的时间运算符和ObserveEveryValueChanged.

如果你想使用微协程替代Unity自带的协程(Coroutine),使用MainThreadDispatcher.StartUpdateMicroCoroutine 或者Observable.FromMicroCoroutine.

int counter; IEnumerator Worker() { while(true) { counter++; yield return null; } } void Start() { for(var i = 0; i < 10000; i++) { // fast, memory efficient MainThreadDispatcher.StartUpdateMicroCoroutine(Worker()); // slow... // StartCoroutine(Worker()); } }

当然微协程存在一些限制,经支持yield return null 迭代,并且其更新时间取决于启动微协程的方法(StartUpdateMicroCoroutine,StartFixedUpdateMicroCoroutine,StartEndOfFrameMicroCoroutine)。

如果和其它IObservable结合起来,你可以检测已完成的属性,比如:isDone.

IEnumerator MicroCoroutineWithToYieldInstruction() { var www = ObservableWWW.Get("http://aaa").ToYieldInstruction(); while (!www.IsDone) { yield return null; } if (www.HasResult) { UnityEngine.Debug.Log(www.Result); } }

UGUI 集成


UniRx可以很容易的处理UnityEvent,使用UnityEvent.AsObservable 订阅事件:

public Button MyButton; // --- MyButton.onClick.AsObservable().Subscribe(_ => Debug.Log("clicked"));

将事件视为可观察对象可启用声明式UI编程。

public Toggle MyToggle; public InputField MyInput; public Text MyText; public Slider MySlider; // On Start, you can write reactive rules for declaretive/reactive ui programming void Start() { // Toggle, Input etc as Observable (OnValueChangedAsObservable is a helper providing isOn value on subscribe) // SubscribeToInteractable is an Extension Method, same as .interactable = x) MyToggle.OnValueChangedAsObservable().SubscribeToInteractable(MyButton); // Input is displayed after a 1 second delay MyInput.OnValueChangedAsObservable() .Where(x => x != null) .Delay(TimeSpan.FromSeconds(1)) .SubscribeToText(MyText); // SubscribeToText is helper for subscribe to text // Converting for human readability MySlider.OnValueChangedAsObservable() .SubscribeToText(MyText, x => Math.Round(x, 2).ToString()); }

更多响应式UI编程,请参考Sample12,Sample13和下面的ReactiveProperty部分。

ReactiveProperty,ReactiveCollection


游戏数据通常需要通知,我们应该使用属性和事件回调吗?这样的话,简直太麻烦了,还好UniRx为我们提供了ReactiveProperty,轻量级的属性代理人。

// Reactive Notification Model public class Enemy { public ReactiveProperty<long> CurrentHp { get; private set; } public ReactiveProperty<bool> IsDead { get; private set; } public Enemy(int initialHp) { // Declarative Property CurrentHp = new ReactiveProperty<long>(initialHp); IsDead = CurrentHp.Select(x => x <= 0).ToReactiveProperty(); } } // --- // onclick, HP decrement MyButton.OnClickAsObservable().Subscribe(_ => enemy.CurrentHp.Value -= 99); // subscribe from notification model. enemy.CurrentHp.SubscribeToText(MyText); enemy.IsDead.Where(isDead => isDead == true) .Subscribe(_ => { MyButton.interactable = false; });

你可以组合使用UnityEvent.AsObservable返回的ReactiveProperties、ReactuveCollections和Observables.所有的UI元素都可作为可观察对象(Observable).

泛型ReactiveProperties不能被序列化或者在Unity的Inspecatble中显示。但是UniRx为ReactivePropery提供了专门的子类,诸如 int/LongReactiveProperty,Float/DoubleReactiveProperty,StringReactiveProperty,BoolReactiveProperty 等等。(在这查看:(InspectableReactiveProperty.cs),这些属性都可以在Inspector中编辑,对于你自定义的Enum ReactiveProperty,编写一个自定义的inspectable ReactiveProperty[T]是很容易的。如果你需要为ReactiveProperty增加[Myltiline]或者[Range]之类的属性,你可以使用MultilineReactivePropertyAttribute和RangeReactivePropertyAttribute 替换Unity的Multiline和Range。

所提供的派生自InspecetableReactiveProperty显示在Inspector中,在值发生更改时发出通知,在Inspector中更改值时也会发出通知。 这个功能由 InspectorDisplayDrawer提供,通过继承你可以应用你自己自定义的ReactiveProperty:

public enum Fruit { Apple, Grape } [Serializable] public class FruitReactiveProperty : ReactiveProperty<Fruit> { public FruitReactiveProperty() { } public FruitReactiveProperty(Fruit initialValue) :base(initialValue) { } } [UnityEditor.CustomPropertyDrawer(typeof(FruitReactiveProperty))] [UnityEditor.CustomPropertyDrawer(typeof(YourSpecializedReactiveProperty2))] // and others... public class ExtendInspectorDisplayDrawer : InspectorDisplayDrawer { }

如果ReactiveProperty仅在流中被更新,通过使用ReadOnlyReactiveProperty你可以将属性变为只读的。

public class Person { public ReactiveProperty<string> GivenName { get; private set; } public ReactiveProperty<string> FamilyName { get; private set; } public ReadOnlyReactiveProperty<string> FullName { get; private set; } public Person(string givenName, string familyName) { GivenName = new ReactiveProperty<string>(givenName); FamilyName = new ReactiveProperty<string>(familyName); // If change the givenName or familyName, notify with fullName! FullName = GivenName.CombineLatest(FamilyName, (x, y) => x + " " + y).ToReadOnlyReactiveProperty(); } }

Model-View-(Reactive)Presenter Pattern


UniRx使得MVP(MVRP)模式的实现成为可能。

为什么我们需要使用MVP模式替换MVVM模式。Unity中没有提供UI绑定机制,创建绑定层太过于复杂且会影响性能。尽管如此,视图任然需要更新。Presenter持有视图的组件并能更新视图。虽然不是真正的绑定,但Observables 启用了对通知的订阅,它看起来更真实,这个模式被称为Reactive Presenter.

// Presenter for scene(canvas) root. public class ReactivePresenter : MonoBehaviour { // Presenter is aware of its View (binded in the inspector) public Button MyButton; public Toggle MyToggle; // State-Change-Events from Model by ReactiveProperty Enemy enemy = new Enemy(1000); void Start() { // Rx supplies user events from Views and Models in a reactive manner MyButton.OnClickAsObservable().Subscribe(_ => enemy.CurrentHp.Value -= 99); MyToggle.OnValueChangedAsObservable().SubscribeToInteractable(MyButton); // Models notify Presenters via Rx, and Presenters update their views enemy.CurrentHp.SubscribeToText(MyText); enemy.IsDead.Where(isDead => isDead == true) .Subscribe(_ => { MyToggle.interactable = MyButton.interactable = false; }); } } // The Model. All property notify when their values change public class Enemy { public ReactiveProperty<long> CurrentHp { get; private set; } public ReactiveProperty<bool> IsDead { get; private set; } public Enemy(int initialHp) { // Declarative Property CurrentHp = new ReactiveProperty<long>(initialHp); IsDead = CurrentHp.Select(x => x <= 0).ToReactiveProperty(); } }

在Unity的Hierarchy中,视图就是一个场景。视图在初始化时有UnityEngine和Presenters关联。xxxAsObservable方法使得创建事件信号变得简单,没有任何开销。SubscribeToText和SubscribeToInteractable是类似绑定的简单的工具。虽然简单,但是非常强大。他们很符合Unity的编程环境,并提供了高性能和简洁的体系结构。

V->RP->M->RP->V以响应式的方式完成的连接起来,UniRx提供了适配的方法和类。当然你也可以使用其它的MVVM(或者MV*) 框架代替,UniRx/ReactiveProperty仅仅是一个简单的工具集。

GUI编程也受益于ObservableTriggers.ObservableTriggers转化Unity事件为Observables(可观察对象),因此可以使用它们来组成MV®P模式。例如:ObservableEventTrigger 转化UGUI事件为Observable(可观察对象):

var eventTrigger = this.gameObject.AddComponent<ObservableEventTrigger>(); eventTrigger.OnBeginDragAsObservable() .SelectMany(_ => eventTrigger.OnDragAsObservable(), (start, current) => UniRx.Tuple.Create(start, current)) .TakeUntil(eventTrigger.OnEndDragAsObservable()) .RepeatUntilDestroy(this) .Subscribe(x => Debug.Log(x));

ReactiveCommand,AsyncReactiveCommand


ReactiveCommand作为可交互按钮命令的抽象。

public class Player { public ReactiveProperty<int> Hp; public ReactiveCommand Resurrect; public Player() { Hp = new ReactiveProperty<int>(1000); // If dead, can not execute. Resurrect = Hp.Select(x => x <= 0).ToReactiveCommand(); // Execute when clicked Resurrect.Subscribe(_ => { Hp.Value = 1000; }); } } public class Presenter : MonoBehaviour { public Button resurrectButton; Player player; void Start() { player = new Player(); // If Hp <= 0, can't press button. player.Resurrect.BindTo(resurrectButton); } }

AsyncReactiveCommand 是ReactiveCommand的异步形式,将CanExecute(大多数情况下绑定到按钮的interactable)更改为false,直到异步操作执行完成。

public class Presenter:MonoBehaviour{ public UnityEngine.UI.Button button; void Start(){ var command=new AsyncReactiveCommand(); command.Subscribe(_=>{ return Observable.Timer(TimeSpan.FromSeconds(3)).asUnitObservable(); }); command.BindTo(button); button.BindToOnClick(_=>{ return Observable.Timer(TimeSpan.FromSeconds(3)).AsUnitObservable(); }); } }

AsyncReactiveCommand 有三个构造函数。

()CanExecute默认为false,直到异步执行完成(IObservable canExecuteSource) 当canExecuteSource发送true并且不在执行时,与empty混合,CanExecute变为true.(IReactiveProperty sharedCanExecute) 在多个AsyncReactiveCommands之间共享执行状态,如果其中一个AsyncReactiveCommand正在执行,其它AsyncReactiveCommands(拥有一个sharedCanExecute属性)的CanExecute变为false,直到这个AsyncCommand异步执行完成. public class Presenter : MonoBehaviour { public UnityEngine.UI.Button button1; public UnityEngine.UI.Button button2; void Start() { // share canExecute status. // when clicked button1, button1 and button2 was disabled for 3 seconds. var sharedCanExecute = new ReactiveProperty<bool>(); button1.BindToOnClick(sharedCanExecute, _ => { return Observable.Timer(TimeSpan.FromSeconds(3)).AsUnitObservable(); }); button2.BindToOnClick(sharedCanExecute, _ => { return Observable.Timer(TimeSpan.FromSeconds(3)).AsUnitObservable(); }); } }

MessageBroker, AsyncMessageBroker


MessageBroker基于Rx的内存的pubsub系统的按类型过滤的。

public class TestArgs { public int Value { get; set; } } --- // Subscribe message on global-scope. MessageBroker.Default.Receive<TestArgs>().Subscribe(x => UnityEngine.Debug.Log(x)); // Publish message MessageBroker.Default.Publish(new TestArgs { Value = 1000 });

AsyncMessageBroker是MessageBroker的异步形式,可以await发布调用

AsyncMessageBroker.Default.Subscribe<TestArgs>(x => { // show after 3 seconds. return Observable.Timer(TimeSpan.FromSeconds(3)) .ForEachAsync(_ => { UnityEngine.Debug.Log(x); }); }); AsyncMessageBroker.Default.PublishAsync(new TestArgs { Value = 3000 }) .Subscribe(_ => { UnityEngine.Debug.Log("called all subscriber completed"); });

UniRx.ToolKit

UniRx.ToolKit 中包含一些Rx-ish工具。当前版本中包含 ObjectPool(对象池)和AsyncObjectPool(异步对象池),这个池子在租赁前可以租、回收和异步预加载。

// sample class public class Foobar : MonoBehaviour { public IObservable<Unit> ActionAsync() { // heavy, heavy, action... return Observable.Timer(TimeSpan.FromSeconds(3)).AsUnitObservable(); } } public class FoobarPool : ObjectPool<Foobar> { readonly Foobar prefab; readonly Transform hierarchyParent; public FoobarPool(Foobar prefab, Transform hierarchyParent) { this.prefab = prefab; this.hierarchyParent = hierarchyParent; } protected override Foobar CreateInstance() { var foobar = GameObject.Instantiate<Foobar>(prefab); foobar.transform.SetParent(hierarchyParent); return foobar; } // You can overload OnBeforeRent, OnBeforeReturn, OnClear for customize action. // In default, OnBeforeRent = SetActive(true), OnBeforeReturn = SetActive(false) // protected override void OnBeforeRent(Foobar instance) // protected override void OnBeforeReturn(Foobar instance) // protected override void OnClear(Foobar instance) } public class Presenter : MonoBehaviour { FoobarPool pool = null; public Foobar prefab; public Button rentButton; void Start() { pool = new FoobarPool(prefab, this.transform); rentButton.OnClickAsObservable().Subscribe(_ => { var foobar = pool.Rent(); foobar.ActionAsync().Subscribe(__ => { // if action completed, return to pool pool.Return(foobar); }); }); } }

Visual Studio Analyzer


对Visual Studio 2015的用户来说,UniRx提供了一个自定义的分析工具————UniRxAnalyzer。例如:检测流什么时候没有被订阅。

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Install-Package UniRxAnalyzer

请在github的Issuse中提交你的关于Analyzer的新想法。

案例

看UniRx/Examples

Windows Store/Phone App (NETFX_CORE)


一些接口,例如UniRx.IObservable和System.IObservable ,当提交应用到Windows Store App时会引起冲突,因此,当时用NETFX_CORE时,请不要使用诸如UniRx.IObservable这样的结构,使用其简短的形式,不要添加命名空间,冲突就解决了。

分离DLL


如果你想使用预构建的UniRx,你可以构建自己的dll,克隆这个项目并打开UniRx.sln,你会看到这是一个完全分离的项目。你需要像这样定义编译宏定义UNITY;UNITY_5_4_OR_NEWER;UNITY_5_4_0;UNITY_5_4;UNITY_5; + UNITY_EDITOR, UNITY_IPHONE或者其它平台宏定义,在发布页面我们不提供预编译二进制文件,因为在asset store 中的编译符号各不相同。

参考


UniRx/wiki UniRx API 文档:

ReactiveX ReactiveX的主页.介绍,[所有运算符(http://reactivex.io/documentation/operators.html)以图形化的方式来说明和讲解,使得理解起来更加容易。UniRxshReactiveX的官方语言。

Introduction to Rx

非常棒的在线教程和电子书

Beginner’s Guide to the Reactive Extensions

更多Rx的视频、ppt和文档

Reactive Programming, ​Unity 3D and you

Repository of UniRxSimpleGame

PPT介绍 By @@torisoup

Repository of UniRxSimpleGame

PPT介绍和游戏示例 By @Xerios

GDC 2016 Sessions of Adventure Capialist

更多内容,欢迎访问:

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