Tôi gọi nhiều Trình xử lý bằng Trình xử lý mới (). PostDelayed (new Runnable () ..... Làm cách nào để dừng lại khi nhấp vào quay lại?
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);
}
}
Tôi gặp sự cố là Trình xử lý của tôi không có tên như "myHandler". Làm thế nào tôi có thể xử lý nó?
Cảm ơn vì sự giúp đỡ!
Bây giờ tôi gặp lỗi sau:
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)