blocks|key|1379528|text|对您的示例的简单修复是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1379529|handler+=+new+Handler();

final+Runnable+r+=+new+Runnable()+{
++++public+void+run()+{
++++++++tv.append("Hello+World");
++++++++handler.postDelayed(this,+1000);
++++}
};

handler.postDelayed(r,+1000);|code-block|syntax|javascript|1379530|或者我们可以使用普通线程(例如，使用原始Runner)：|1379531|Thread+thread+=+new+Thread()+{
++++@Override
++++public+void+run()+{
++++++++try+{
++++++++++++while(true)+{
++++++++++++++++sleep(1000);
++++++++++++++++handler.post(this);
++++++++++++}
++++++++}+catch+(InterruptedException+e)+{
++++++++++++e.printStackTrace();
++++++++}
++++}
};

thread.start();|1379532|您可以将runnable对象看作是可以发送到消息队列以供执行的命令，而handler仅仅是用于发送该命令的辅助对象。|1379533|更多细节在这里http://developer.android.com/reference/android/os/Handler.html|offset|length|1379534|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/os/Handler.html^0|0|0|0|0|0|7|1Q|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@$O|14|P|15|1|16]]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

<p>The simple fix to your example is :</p>

<pre><code>handler = new Handler();

final Runnable r = new Runnable() {
    public void run() {
        tv.append("Hello World");
        handler.postDelayed(this, 1000);
    }
};

handler.postDelayed(r, 1000);
</code></pre>

<p>Or we can use normal thread for example (with original Runner) :</p>

<pre><code>Thread thread = new Thread() {
    @Override
    public void run() {
        try {
            while(true) {
                sleep(1000);
                handler.post(this);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

thread.start();
</code></pre>

<p>You may consider your runnable object just as a command that can be sent to the message queue for execution, and handler as just a helper object used to send that command.</p>

<p>More details are here <a href="http://developer.android.com/reference/android/os/Handler.html" rel="noreferrer">http://developer.android.com/reference/android/os/Handler.html</a></p>


blocks|key|1379569|text|new+Handler().postDelayed(new+Runnable()+{
++++public+void+run()+{
++++++++//+do+something...++++++++++++++
++++}
},+100);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1379570|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>new Handler().postDelayed(new Runnable() {
    public void run() {
        // do something...              
    }
}, 100);
</code></pre>


blocks|key|1379544|text|Handler+handler=new+Handler();
Runnable+r+=+new+Runnable(){
++++public+void+run()+{
++++++++tv.append("Hello+World");+++++++++++++++++++++++
++++++++handler.postDelayed(r,+1000);
++++}
};+
handler.post(r);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1379545|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>Handler handler=new Handler();
Runnable r = new Runnable(){
    public void run() {
        tv.append("Hello World");                       
        handler.postDelayed(r, 1000);
    }
}; 
handler.post(r);
</code></pre>


blocks|key|1379710|text|Kotlin|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1379711|private+lateinit+var+runnable:+Runnable
override+fun+onCreate(savedInstanceState:+Bundle?)+{
++++val+handler+=+Handler()
++++runnable+=+Runnable+{
++++++++//+do+your+work
++++++++handler.postDelayed(runnable,+2000)
++++}
++++handler.postDelayed(runnable,+2000)
}|code-block|syntax|javascript|1379712|Java|1379713|Runnable+runnable;
Handler+handler;

@Override
protected+void+onCreate(@Nullable+Bundle+savedInstanceState)+{
++++handler+=+new+Handler();
++++runnable+=+new+Runnable()+{
++++++++@Override
++++++++public+void+run()+{
++++++++++++//+do+your+work
++++++++++++handler.postDelayed(this,+1000);
++++++++}
++++};
++++handler.postDelayed(runnable,+1000);
}|1379714|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<h3>Kotlin</h3>

<pre><code>private lateinit var runnable: Runnable
override fun onCreate(savedInstanceState: Bundle?) {
    val handler = Handler()
    runnable = Runnable {
        // do your work
        handler.postDelayed(runnable, 2000)
    }
    handler.postDelayed(runnable, 2000)
}
</code></pre>

<h3>Java</h3>

<pre><code>Runnable runnable;
Handler handler;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    handler = new Handler();
    runnable = new Runnable() {
        @Override
        public void run() {
            // do your work
            handler.postDelayed(this, 1000);
        }
    };
    handler.postDelayed(runnable, 1000);
}
</code></pre>


blocks|key|1164728|text|使用协程的Kotlin|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1164729|在Kotlin中，使用协程可以执行以下操作：|1164730|CoroutineScope(Dispatchers.Main).launch+{+//+Main,+because+UI+is+changed
++++ticker(delayMillis+=+1000,+initialDelayMillis+=+1000).consumeEach+{
++++++++tv.append("Hello+World")
++++}
}|code-block|syntax|javascript|1164731|试试吧，here！|offset|length|1164732|entityMap|0|LINK|mutability|MUTABLE|url|https://pl.kotl.in/EYb_7GfJK^0|0|0|0|4|4|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<h2>Kotlin with Coroutines</h2>

<p>In Kotlin, using coroutines you can do the following:</p>

<pre><code>CoroutineScope(Dispatchers.Main).launch { // Main, because UI is changed
    ticker(delayMillis = 1000, initialDelayMillis = 1000).consumeEach {
        tv.append("Hello World")
    }
}
</code></pre>

<p>Try it out <a href="https://pl.kotl.in/EYb_7GfJK" rel="nofollow noreferrer">here</a>!</p>


blocks|key|1164584|text|一个有趣的例子是，您可以连续看到计数器/秒表在单独的线程中运行。还显示了GPS定位。而主活动用户界面线程已经存在。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1164585|摘录：|1164586|try+{++++
++++cnt%2B%2B;+scnt%2B%2B;
++++now=System.currentTimeMillis();
++++r=rand.nextInt(6);+r%2B%2B;++++
++++loc=lm.getLastKnownLocation(best);++++

++++if(loc!=null)+{+
++++++++lat=loc.getLatitude();
++++++++lng=loc.getLongitude();+
++++}++++

++++Thread.sleep(100);+
++++handler.sendMessage(handler.obtainMessage());
}+catch+(InterruptedException+e)+{+++
++++Toast.makeText(this,+"Error="%2Be.toString(),+Toast.LENGTH_LONG).show();
}|code-block|syntax|javascript|1164587|要查看代码，请参阅此处：|1164588|Thread+example+displaying+GPS+Location+and+Current+Time+runnable+alongside+main-activity's+User+Interface+Thread|offset|length|1164589|entityMap|0|LINK|mutability|MUTABLE|url|https://letsmakeandroidapp.wordpress.com/2017/08/25/step-7-learning-thread-with-roll-dice-static-counter-and-gps-location/^0|0|0|0|0|0|34|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

<p>An interesting example is you can continuously see a counter/stop-watch running in separate thread. Also showing GPS-Location. While main activity User Interface Thread is already there.</p>

<p>Excerpt:</p>

<pre><code>try {    
    cnt++; scnt++;
    now=System.currentTimeMillis();
    r=rand.nextInt(6); r++;    
    loc=lm.getLastKnownLocation(best);    

    if(loc!=null) { 
        lat=loc.getLatitude();
        lng=loc.getLongitude(); 
    }    

    Thread.sleep(100); 
    handler.sendMessage(handler.obtainMessage());
} catch (InterruptedException e) {   
    Toast.makeText(this, "Error="+e.toString(), Toast.LENGTH_LONG).show();
}
</code></pre>

<p>To look at code see here:</p>

<p><a href="https://letsmakeandroidapp.wordpress.com/2017/08/25/step-7-learning-thread-with-roll-dice-static-counter-and-gps-location/" rel="nofollow noreferrer">Thread example displaying GPS Location and Current Time runnable alongside main-activity's User Interface Thread</a></p>


blocks|key|1379678|text|现在在Kotlin中，你可以这样运行线程：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1379679|class+SimpleRunnable:+Runnable+{
++++public+override+fun+run()+{
++++++++println("${Thread.currentThread()}+has+run.")
++++}
}
fun+main(args:+Array<String>)+{
++++val+thread+=+SimpleThread()
++++thread.start()+//+Will+output:+Thread[Thread-0,5,main]+has+run.
++++val+runnable+=+SimpleRunnable()
++++val+thread1+=+Thread(runnable)
++++thread1.start()+//+Will+output:+Thread[Thread-1,5,main]+has+run
}|code-block|syntax|javascript|1379680|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>now in Kotlin you can run threads this way:</p>

<pre><code>class SimpleRunnable: Runnable {
    public override fun run() {
        println("${Thread.currentThread()} has run.")
    }
}
fun main(args: Array&lt;String&gt;) {
    val thread = SimpleThread()
    thread.start() // Will output: Thread[Thread-0,5,main] has run.
    val runnable = SimpleRunnable()
    val thread1 = Thread(runnable)
    thread1.start() // Will output: Thread[Thread-1,5,main] has run
}
</code></pre>


<p>I developed an application to display some text at defined intervals in the Android emulator screen. I am using the <code>Handler</code> class. Here is a snippet from my code:</p>

<pre><code>handler = new Handler();
Runnable r = new Runnable() {
    public void run() {
        tv.append("Hello World");               
    }
};
handler.postDelayed(r, 1000);
</code></pre>

<p>When I run this application the text is displayed only once. Why?</p>


How to run a Runnable thread in Android at defined intervals?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

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我开发了一个应用程序，可以在Android模拟器屏幕上以指定的时间间隔显示一些文本。我使用的是Handler类。下面是我的代码中的一段代码：handler = new Handler();Runnable r = new Runnable() {    public void run() {        tv.append("Hello World");                   }}

问如何在Android中以定义的时间间隔运行可运行线程？
EN

回答 7

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问如何在Android中以定义的时间间隔运行可运行线程？EN

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问如何在Android中以定义的时间间隔运行可运行线程？
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