Android 停止 handler.postDelayed()
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22718951/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Stop handler.postDelayed()
提问by basti12354
I call multiple Handlers by new Handler().postDelayed(new Runnable()..... How can I stop it when I click on back?
我通过 new Handler().postDelayed(new Runnable()..... 当我点击返回时如何停止它？
public class MyActivity extends AppCompatActivity implements OnClickListener {
private Button btn;
private Handler handler;
private Runnable myRunnable;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
btn = (Button) findViewById(R.id.trainingsstart);
btn.setOnClickListener(this);
}
@Override
public void onClick(View v) {
Handler handler = new Handler();
Runnable myRunnable = new Runnable() {
public void run() {
// Things to be done
}
};
handler.postDelayed(myRunnable, 3000);
}
@Override
public void onBackPressed() {
super.onBackPressed();
handler.removeCallbacks(myRunnable);
}
}
I have the problem that my Handlers haven't a name like "myHandler". How can I handle it?
我的问题是我的处理程序没有像“myHandler”这样的名字。我该如何处理？
Thanks for help!
感谢帮助！
Now I got these error:
现在我得到了这些错误：
03-28 17:47:03.662: E/AndroidRuntime(1961): FATAL EXCEPTION: main
03-28 17:47:03.662: E/AndroidRuntime(1961): java.lang.NullPointerException
03-28 17:47:03.662: E/AndroidRuntime(1961): at de.basti12354.tage.uebungen.Tag1.onBackPressed(Tag1.java:120)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.app.Activity.onKeyUp(Activity.java:2159)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.KeyEvent.dispatch(KeyEvent.java:2647)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.app.Activity.dispatchKeyEvent(Activity.java:2389)
03-28 17:47:03.662: E/AndroidRuntime(1961): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1860)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:3791)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3774)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3379)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3429)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3398)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3483)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3406)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3540)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3379)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3429)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3398)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3406)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3379)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3429)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3398)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3516)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.ViewRootImpl$ImeInputStage.onFinishedInputEvent(ViewRootImpl.java:3666)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.inputmethod.InputMethodManager$PendingEvent.run(InputMethodManager.java:1982)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.inputmethod.InputMethodManager.invokeFinishedInputEventCallback(InputMethodManager.java:1698)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.inputmethod.InputMethodManager.finishedInputEvent(InputMethodManager.java:1689)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.inputmethod.InputMethodManager$ImeInputEventSender.onInputEventFinished(InputMethodManager.java:1959)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.view.InputEventSender.dispatchInputEventFinished(InputEventSender.java:141)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.os.MessageQueue.nativePollOnce(Native Method)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.os.MessageQueue.next(MessageQueue.java:132)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.os.Looper.loop(Looper.java:124)
03-28 17:47:03.662: E/AndroidRuntime(1961): at android.app.ActivityThread.main(ActivityThread.java:5103)
03-28 17:47:03.662: E/AndroidRuntime(1961): at java.lang.reflect.Method.invokeNative(Native Method)
03-28 17:47:03.662: E/AndroidRuntime(1961): at java.lang.reflect.Method.invoke(Method.java:525)
03-28 17:47:03.662: E/AndroidRuntime(1961): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-28 17:47:03.662: E/AndroidRuntime(1961): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-28 17:47:03.662: E/AndroidRuntime(1961): at dalvik.system.NativeStart.main(Native Method)
回答by Raghunandan
You can use:
您可以使用：
Handler handler = new Handler()
handler.postDelayed(new Runnable())
Or you can use:
或者你可以使用：
handler.removeCallbacksAndMessages(null);
Docs
文档
public final void removeCallbacksAndMessages (Object token)
Added in API level 1 Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed.
public final void removeCallbacksAndMessages（对象令牌）
在 API 级别 1 中添加删除任何挂起的回调和已发送其 obj 为令牌的消息。如果 token 为空，所有回调和消息将被删除。
Or you could also do like the following:
或者您也可以执行以下操作：
Handler handler = new Handler()
Runnable myRunnable = new Runnable() {
public void run() {
// do something
}
};
handler.postDelayed(myRunnable,zeit_dauer2);
Then:
然后：
handler.removeCallbacks(myRunnable);
Docs
文档
public final void removeCallbacks (Runnable r)
Added in API level 1 Remove any pending posts of Runnable r that are in the message queue.
public final void removeCallbacks (Runnable r, Object token)
public final void removeCallbacks (Runnable r)
在 API 级别 1 中添加删除消息队列中的 Runnable r 的所有待处理帖子。
public final void removeCallbacks (Runnable r, Object token)
Edit:
编辑：
Change this:
改变这个：
@Override
public void onClick(View v) {
Handler handler = new Handler();
Runnable myRunnable = new Runnable() {
To:
到：
@Override
public void onClick(View v) {
handler = new Handler();
myRunnable = new Runnable() { /* ... */}
Because you have the below. Declared before onCreatebut you re-declared and then initialized it in onClickleading to a NPE.
因为你有下面的。之前已声明，onCreate但您重新声明然后将其初始化以onClick导致 NPE。
Handler handler; // declared before onCreate
Runnable myRunnable;
回答by Emre AYDIN
You can define a boolean and change it to false when you want to stop handler. Like this..
您可以定义一个布尔值，并在要停止处理程序时将其更改为 false。像这样..
boolean stop = false;
handler.postDelayed(new Runnable() {
@Override
public void run() {
//do your work here..
if (!stop) {
handler.postDelayed(this, delay);
}
}
}, delay);
回答by ralphgabb
this may be old, but for those looking for answer you can use this...
这可能很旧，但是对于那些寻找答案的人，您可以使用它...
public void stopHandler() {
handler.removeMessages(0);
}
cheers
干杯
回答by vinay shetty
Boolean condition=false; //Instance variable declaration.
//-----------------Inside oncreate---------------------------------------------------
start =(Button)findViewById(R.id.id_start);
start.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
starthandler();
if(condition=true)
{
condition=false;
}
}
});
stop=(Button) findViewById(R.id.id_stoplocatingsmartplug);
stop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
stophandler();
}
});
}
//-----------------Inside oncreate---------------------------------------------------
public void starthandler()
{
handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if(!condition)
{
//Do something after 100ms
}
}
}, 5000);
}
public void stophandler()
{
condition=true;
}
