Android RxKotlin-订阅错误,观察到主题在活动之外的线程更改?
我有一个在随机时刻生成不同字符串的对象,我需要向这个生成器进行sudscribe,以获取这些字符串并将其提供给ui(可能是不同活动中的多个订阅者)。 假设我得到了以下代码: 发电机:Android RxKotlin-订阅错误,观察到主题在活动之外的线程更改?,android,multithreading,kotlin-android-extensions,rx-kotlin,rx-kotlin2,Android,Multithreading,Kotlin Android Extensions,Rx Kotlin,Rx Kotlin2,我有一个在随机时刻生成不同字符串的对象,我需要向这个生成器进行sudscribe,以获取这些字符串并将其提供给ui(可能是不同活动中的多个订阅者)。 假设我得到了以下代码: 发电机: class Generator { private var stringToGenerate = "" var subject: BehaviorSubject<String> = BehaviorSubject.create<String>() init {
class Generator {
private var stringToGenerate = ""
var subject: BehaviorSubject<String> = BehaviorSubject.create<String>()
init {
//seems like these instructions are skipped
subject
.subscribeOn(AndroidSchedulers.mainThread())
.doOnNext { t -> Log.i("subject doOnNext", Thread.currentThread().name + " " + Thread.currentThread().id) }
.observeOn(AndroidSchedulers.mainThread())
.map { _ -> Log.i("subject map", Thread.currentThread().name + " " + Thread.currentThread().id) }
//imitation of async creating of strings in separate thread
timer("timerThread", false, 2000L, 2000L) {
stringToGenerate = System.currentTimeMillis().toString()
subject.onNext(stringToGenerate)
}
}
}
类生成器{
private var stringToGenerate=“”
var subject:BehaviorSubject=BehaviorSubject.create()
初始化{
//似乎这些说明被跳过了
主题
.subscribeOn(AndroidSchedulers.mainThread())
.doOnNext{t->Log.i(“主题doOnNext”,Thread.currentThread().name+“”+Thread.currentThread().id)}
.observeOn(AndroidSchedulers.mainThread())
.map{->Log.i(“主题映射”,Thread.currentThread().name+“”+Thread.currentThread().id)}
//模拟在单独线程中异步创建字符串
计时器(“timerThread”,假,2000L,2000L){
stringToGenerate=System.currentTimeMillis().toString()
subject.onNext(stringToGenerate)
}
}
}
必须使用生成字符串的活动之一:
class TestActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_test)
val wrongThreadObserver = object : Observer<String> {
override fun onComplete() {
}
override fun onSubscribe(d: Disposable) {
}
override fun onNext(t: String) {
Log.i("wrongThreadObserver", Thread.currentThread().name + " " + Thread.currentThread().id)
}
override fun onError(e: Throwable) {
}
}
val generator = Generator()
generator.subject.subscribe(wrongThreadObserver)
//for correct work illustration
val correctThreadObserver = object : Observer<String> {
override fun onComplete() {
}
override fun onSubscribe(d: Disposable) {
}
override fun onNext(t: String) {
Log.i("correctThreadObserver", Thread.currentThread().name + " " + Thread.currentThread().id)
}
override fun onError(e: Throwable) {
}
}
val mainThreadSubject = BehaviorSubject.create<String>()
mainThreadSubject
.doOnNext { obj -> Log.i("correctThread doOnNext", Thread.currentThread().name + " " + Thread.currentThread().id) }
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.newThread())
.subscribe(correctThreadObserver)
mainThreadSubject.onNext("test thread")
val handler = Handler()
handler.postDelayed({ mainThreadSubject.onNext("test thread 2") }, 1000)
handler.postDelayed({ mainThreadSubject.onNext("test thread 3") }, 2000)
}
}
类测试活动:AppCompatActivity(){
重写创建时的乐趣(savedInstanceState:Bundle?){
super.onCreate(savedInstanceState)
setContentView(R.layout.activity\u测试)
val=对象:观察者{
覆盖有趣的onComplete(){
}
覆盖订阅的乐趣(d:一次性){
}
覆盖文本(t:字符串){
Log.i(“错误线程观察者”,Thread.currentThread().name+“”+Thread.currentThread().id)
}
覆盖有趣的错误(e:可丢弃){
}
}
val生成器=生成器()
generator.subject.subscribe(观察者)
//正确的工作说明
val correctThreadObserver=对象:观察者{
覆盖有趣的onComplete(){
}
覆盖订阅的乐趣(d:一次性){
}
覆盖文本(t:字符串){
Log.i(“correctThreadObserver”,Thread.currentThread().name+“”+Thread.currentThread().id)
}
覆盖有趣的错误(e:可丢弃){
}
}
val mainThreadSubject=BehaviorSubject.create()
主语
.doOnNext{obj->Log.i(“correctThread doOnNext”,Thread.currentThread().name+“”+Thread.currentThread().id)}
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.newThread())
.订阅(观察员)
mainThreadSubject.onNext(“测试线程”)
val handler=handler()
handler.postDelayed({mainThreadSubject.onNext(“测试线程2”)},1000)
handler.postDelayed({mainThreadSubject.onNext(“测试线程3”)},2000)
}
}
在本例中,correctThreadObserver仅在活动中创建,工作正常,但ErrorThreadObserver在计时器线程中保持工作,似乎它忽略了生成器中的指令subscribeOn、ObserveOn、doOnNext,无论这些指令在初始化中、计时器线程中的何处调用,在活动中,通过从生成器获取对象-ErrorThreadObserver仍在计时器线程中工作。
所以日志是:
I/D下一步:主2
I/correctThreadObserver:RxNewThreadScheduler-1 941
I/D下一步:主2
I/correctThreadObserver:RxNewThreadScheduler-1 941
I/O线程观察员:时间读取937
I/D下一步:主2
I/correctThreadObserver:RxNewThreadScheduler-1 941
I/O线程观察员:时间读取937
I/O线程观察员:时间读取937
I/O线程观察员:时间读取937
没有doOnNext
和ErrorThreadObserver的主线程
我做错了什么?我找到了以下解决方案:
我们必须订阅observeable
,而不是Subject
,因此我们必须使用方法observeOn()
的结果,而不是对象“Subject”本身。
如果需要多个订阅,我们可以将observeOn
的结果缓存在单独的变量中:
//in Generator
.......
var observableInSeparateVar = subject.observeOn(AndroidSchedulers.mainThread())
.......
//in TestActivity
.......
generator.observableInSeparateVar.subscribe(wrongThreadObserver)
.......
此外,我们还可以调用observeOn()
,在之后进行主题和订阅:
//in TestActivity
.......
generator.subject
.observeOn(AndroidSchedulers.mainThread())
.subscribe(wrongThreadObserver)
用observeOn
替换subscribeOn
,我认为它应该可以工作