我启动了一个可运行但没有将其分配给变量。我该如何阻止它？我知道它是removeCallbacksAndMessages()方法的组合，但我不知道要传递给这个方法什么参数，因为我创建了一个匿名可运行:
mStartButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
h = new Handler();
final int delay = 1000; //milliseconds
h.postDelayed(new Runnable() {
public void run() {
mUpdateRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int mNumberOfPollsForCurrentDay = (int) dataSnapshot.getChildrenCount();
Random r = new Random();
int randomPollInRangeOfCurrentDayNumberOfPolls = r.nextInt((mNumberOfPollsForCurrentDay + 1) - 1) + 1;
int numberOfPollAnswersAtRandomNumber = (int) dataSnapshot.child(String.valueOf(randomPollInRangeOfCurrentDayNumberOfPolls)).child(POLL_ANSWERS_LABEL).getChildrenCount();
Random rr = new Random();
int randomAnswerBasedFromRandomPollAnswerChoices = rr.nextInt((numberOfPollAnswersAtRandomNumber + 1) - 1) + 1;
mUpdateRef.child(String.valueOf(randomPollInRangeOfCurrentDayNumberOfPolls)).child(POLL_ANSWERS_LABEL).child(String.valueOf(randomAnswerBasedFromRandomPollAnswerChoices)).child("Vote_Count").runTransaction(new Transaction.Handler() {
@Override
public Transaction.Result doTransaction(MutableData mutableData) {
mutableData.setValue((Long) mutableData.getValue() + 1);
return Transaction.success(mutableData);
}
@Override
public void onComplete(FirebaseError firebaseError, boolean b, DataSnapshot dataSnapshot) {
}
});
}
@Override
public void onCancelled(FirebaseError firebaseError) {
}
});
h.postDelayed(this, delay);
}
}, delay);
}
});
最佳答案
调用 h.removeCallbacksAndMessages(null) 将删除 documentation 中所述的所有回调和消息。 :
Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed.
请注意，如果可运行程序已经在执行中，这不会停止它，但如果它仍处于挂起状态，则会将其删除。
关于java - 如何从处理程序中删除未分配给变量的 Runnable，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35515788/