如何在android中设置计时器?
有人能举一个简单的例子,每隔一秒钟左右更新一个文本字段吗 我想做一个飞球,需要每秒计算/更新球坐标,这就是为什么我需要某种计时器如何在android中设置计时器?,android,timer,Android,Timer,有人能举一个简单的例子,每隔一秒钟左右更新一个文本字段吗 我想做一个飞球,需要每秒计算/更新球坐标,这就是为什么我需要某种计时器 我没有从中获得任何信息。您需要创建一个线程来处理更新循环,并使用它来更新文本区域。然而,棘手的部分是,只有主线程才能真正修改ui,因此更新循环线程需要向主线程发出更新信号。这是使用处理程序完成的 查看此链接: 用第二个线程单击标题为Example ProgressDialog的部分。这正是你需要做的一个例子,除了使用进度对话框而不是文本字段。这很简单! 创建新的计时器
我没有从中获得任何信息。您需要创建一个线程来处理更新循环,并使用它来更新文本区域。然而,棘手的部分是,只有主线程才能真正修改ui,因此更新循环线程需要向主线程发出更新信号。这是使用处理程序完成的 查看此链接: 用第二个线程单击标题为Example ProgressDialog的部分。这正是你需要做的一个例子,除了使用进度对话框而不是文本字段。这很简单! 创建新的计时器
Timer timer = new Timer();
然后扩展计时器任务
class UpdateBallTask extends TimerTask {
Ball myBall;
public void run() {
//calculate the new position of myBall
}
}
然后以一定的更新间隔将新任务添加到计时器中
final int FPS = 40;
TimerTask updateBall = new UpdateBallTask();
timer.scheduleAtFixedRate(updateBall, 0, 1000/FPS);
免责声明:这不是理想的解决方案。这是按照OP的要求使用计时器类的解决方案。在Android SDK中,建议使用处理程序类,在接受的答案中有一个示例。您希望在已经存在的UI线程中进行UI更新 最好的方法是使用一个处理程序,该处理程序使用postDelayed在一个延迟后运行Runnable,每次运行计划下一次运行;使用removeCallbacks清除回调
您已经找到了正确的位置,所以请再次查看,也许可以澄清为什么代码示例不是您想要的。另请参阅相同的文章。好,因为这一问题尚未解决,因此有3种简单的方法来处理。 下面是一个显示所有3个的示例,底部是一个显示我认为更可取的方法的示例。还记得在onPause中清理任务,必要时保存状态
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Handler.Callback;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class main extends Activity {
TextView text, text2, text3;
long starttime = 0;
//this posts a message to the main thread from our timertask
//and updates the textfield
final Handler h = new Handler(new Callback() {
@Override
public boolean handleMessage(Message msg) {
long millis = System.currentTimeMillis() - starttime;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
seconds = seconds % 60;
text.setText(String.format("%d:%02d", minutes, seconds));
return false;
}
});
//runs without timer be reposting self
Handler h2 = new Handler();
Runnable run = new Runnable() {
@Override
public void run() {
long millis = System.currentTimeMillis() - starttime;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
seconds = seconds % 60;
text3.setText(String.format("%d:%02d", minutes, seconds));
h2.postDelayed(this, 500);
}
};
//tells handler to send a message
class firstTask extends TimerTask {
@Override
public void run() {
h.sendEmptyMessage(0);
}
};
//tells activity to run on ui thread
class secondTask extends TimerTask {
@Override
public void run() {
main.this.runOnUiThread(new Runnable() {
@Override
public void run() {
long millis = System.currentTimeMillis() - starttime;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
seconds = seconds % 60;
text2.setText(String.format("%d:%02d", minutes, seconds));
}
});
}
};
Timer timer = new Timer();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
text = (TextView)findViewById(R.id.text);
text2 = (TextView)findViewById(R.id.text2);
text3 = (TextView)findViewById(R.id.text3);
Button b = (Button)findViewById(R.id.button);
b.setText("start");
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Button b = (Button)v;
if(b.getText().equals("stop")){
timer.cancel();
timer.purge();
h2.removeCallbacks(run);
b.setText("start");
}else{
starttime = System.currentTimeMillis();
timer = new Timer();
timer.schedule(new firstTask(), 0,500);
timer.schedule(new secondTask(), 0,500);
h2.postDelayed(run, 0);
b.setText("stop");
}
}
});
}
@Override
public void onPause() {
super.onPause();
timer.cancel();
timer.purge();
h2.removeCallbacks(run);
Button b = (Button)findViewById(R.id.button);
b.setText("start");
}
}
需要记住的主要一点是,用户界面只能从主用户界面线程进行修改,因此请使用处理程序或活动。runOnUIThreadRunnable r
这是我认为最好的方法。
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class TestActivity extends Activity {
TextView timerTextView;
long startTime = 0;
//runs without a timer by reposting this handler at the end of the runnable
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
@Override
public void run() {
long millis = System.currentTimeMillis() - startTime;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
seconds = seconds % 60;
timerTextView.setText(String.format("%d:%02d", minutes, seconds));
timerHandler.postDelayed(this, 500);
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test_activity);
timerTextView = (TextView) findViewById(R.id.timerTextView);
Button b = (Button) findViewById(R.id.button);
b.setText("start");
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Button b = (Button) v;
if (b.getText().equals("stop")) {
timerHandler.removeCallbacks(timerRunnable);
b.setText("start");
} else {
startTime = System.currentTimeMillis();
timerHandler.postDelayed(timerRunnable, 0);
b.setText("stop");
}
}
});
}
@Override
public void onPause() {
super.onPause();
timerHandler.removeCallbacks(timerRunnable);
Button b = (Button)findViewById(R.id.button);
b.setText("start");
}
}
如果您还需要在UI线程而不是计时器线程上运行代码,请查看博客:
如果有人感兴趣,我开始尝试创建一个标准对象来在活动UI线程上运行。看起来不错。欢迎评论。我希望它能作为一个组件在布局设计器上可用,并拖到活动上。真不敢相信这样的事情还不存在
package com.example.util.timer;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
public class ActivityTimer {
private Activity m_Activity;
private boolean m_Enabled;
private Timer m_Timer;
private long m_Delay;
private long m_Period;
private ActivityTimerListener m_Listener;
private ActivityTimer _self;
private boolean m_FireOnce;
public ActivityTimer() {
m_Delay = 0;
m_Period = 100;
m_Listener = null;
m_FireOnce = false;
_self = this;
}
public boolean isEnabled() {
return m_Enabled;
}
public void setEnabled(boolean enabled) {
if (m_Enabled == enabled)
return;
// Disable any existing timer before we enable a new one
Disable();
if (enabled) {
Enable();
}
}
private void Enable() {
if (m_Enabled)
return;
m_Enabled = true;
m_Timer = new Timer();
if (m_FireOnce) {
m_Timer.schedule(new TimerTask() {
@Override
public void run() {
OnTick();
}
}, m_Delay);
} else {
m_Timer.schedule(new TimerTask() {
@Override
public void run() {
OnTick();
}
}, m_Delay, m_Period);
}
}
private void Disable() {
if (!m_Enabled)
return;
m_Enabled = false;
if (m_Timer == null)
return;
m_Timer.cancel();
m_Timer.purge();
m_Timer = null;
}
private void OnTick() {
if (m_Activity != null && m_Listener != null) {
m_Activity.runOnUiThread(new Runnable() {
@Override
public void run() {
m_Listener.OnTimerTick(m_Activity, _self);
}
});
}
if (m_FireOnce)
Disable();
}
public long getDelay() {
return m_Delay;
}
public void setDelay(long delay) {
m_Delay = delay;
}
public long getPeriod() {
return m_Period;
}
public void setPeriod(long period) {
if (m_Period == period)
return;
m_Period = period;
}
public Activity getActivity() {
return m_Activity;
}
public void setActivity(Activity activity) {
if (m_Activity == activity)
return;
m_Activity = activity;
}
public ActivityTimerListener getActionListener() {
return m_Listener;
}
public void setActionListener(ActivityTimerListener listener) {
m_Listener = listener;
}
public void start() {
if (m_Enabled)
return;
Enable();
}
public boolean isFireOnlyOnce() {
return m_FireOnce;
}
public void setFireOnlyOnce(boolean fireOnce) {
m_FireOnce = fireOnce;
}
}
在活动中,我有一个onStart:
@Override
protected void onStart() {
super.onStart();
m_Timer = new ActivityTimer();
m_Timer.setFireOnlyOnce(true);
m_Timer.setActivity(this);
m_Timer.setActionListener(this);
m_Timer.setDelay(3000);
m_Timer.start();
}
他是更简单的解决方案,在我的应用程序中运行良好
public class MyActivity extends Acitivity {
TextView myTextView;
boolean someCondition=true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
myTextView = (TextView) findViewById(R.id.refreshing_field);
//starting our task which update textview every 1000 ms
new RefreshTask().execute();
}
//class which updates our textview every second
class RefreshTask extends AsyncTask {
@Override
protected void onProgressUpdate(Object... values) {
super.onProgressUpdate(values);
String text = String.valueOf(System.currentTimeMillis());
myTextView.setText(text);
}
@Override
protected Object doInBackground(Object... params) {
while(someCondition) {
try {
//sleep for 1s in background...
Thread.sleep(1000);
//and update textview in ui thread
publishProgress();
} catch (InterruptedException e) {
e.printStackTrace();
};
return null;
}
}
}
这里有一个简单可靠的方法 将以下代码放入活动中,当活动处于恢复状态时,UI线程中将每秒调用tick方法。当然,您可以更改tick方法来执行您想要的操作,或者或多或少地被调用
@Override
public void onPause() {
_handler = null;
super.onPause();
}
private Handler _handler;
@Override
public void onResume() {
super.onResume();
_handler = new Handler();
Runnable r = new Runnable() {
public void run() {
if (_handler == _h0) {
tick();
_handler.postDelayed(this, 1000);
}
}
private final Handler _h0 = _handler;
};
r.run();
}
private void tick() {
System.out.println("Tick " + System.currentTimeMillis());
}
对于那些感兴趣的人来说,_h0=_处理程序代码是必要的,以避免在活动暂停并在计时周期内恢复时两个计时器同时运行
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.TextView;
import android.app.Activity;
public class MainActivity extends Activity {
CheckBox optSingleShot;
Button btnStart, btnCancel;
TextView textCounter;
Timer timer;
MyTimerTask myTimerTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
optSingleShot = (CheckBox)findViewById(R.id.singleshot);
btnStart = (Button)findViewById(R.id.start);
btnCancel = (Button)findViewById(R.id.cancel);
textCounter = (TextView)findViewById(R.id.counter);
btnStart.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
if(timer != null){
timer.cancel();
}
//re-schedule timer here
//otherwise, IllegalStateException of
//"TimerTask is scheduled already"
//will be thrown
timer = new Timer();
myTimerTask = new MyTimerTask();
if(optSingleShot.isChecked()){
//singleshot delay 1000 ms
timer.schedule(myTimerTask, 1000);
}else{
//delay 1000ms, repeat in 5000ms
timer.schedule(myTimerTask, 1000, 5000);
}
}});
btnCancel.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
if (timer!=null){
timer.cancel();
timer = null;
}
}
});
}
class MyTimerTask extends TimerTask {
@Override
public void run() {
Calendar calendar = Calendar.getInstance();
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("dd:MMMM:yyyy HH:mm:ss a");
final String strDate = simpleDateFormat.format(calendar.getTime());
runOnUiThread(new Runnable(){
@Override
public void run() {
textCounter.setText(strDate);
}});
}
}
}
.xml
如果您只想安排一个倒计时,直到将来某个时间,并在这一过程中定期发出通知,那么您可以使用API级别1之后提供的类
new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
editText.setText("Seconds remaining: " + millisUntilFinished / 1000);
}
public void onFinish() {
editText.setText("Done");
}
}.start();
也可以使用动画制作工具:
int secondsToRun = 999;
ValueAnimator timer = ValueAnimator.ofInt(secondsToRun);
timer.setDuration(secondsToRun * 1000).setInterpolator(new LinearInterpolator());
timer.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
{
@Override
public void onAnimationUpdate(ValueAnimator animation)
{
int elapsedSeconds = (int) animation.getAnimatedValue();
int minutes = elapsedSeconds / 60;
int seconds = elapsedSeconds % 60;
textView.setText(String.format("%d:%02d", minutes, seconds));
}
});
timer.start();
我认为你可以这样做:
timerSubscribe = Observable.interval(1, TimeUnit.SECONDS)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<Long>() {
@Override
public void call(Long aLong) {
//TODO do your stuff
}
});
Rx定时器这是定时器的一些简单代码:
Timer timer = new Timer();
TimerTask t = new TimerTask() {
@Override
public void run() {
System.out.println("1");
}
};
timer.scheduleAtFixedRate(t,1000,1000);
对于那些不能依赖的人,我根据以下建议之一制作了一个实用课程:
public class TimerTextHelper implements Runnable {
private final Handler handler = new Handler();
private final TextView textView;
private volatile long startTime;
private volatile long elapsedTime;
public TimerTextHelper(TextView textView) {
this.textView = textView;
}
@Override
public void run() {
long millis = System.currentTimeMillis() - startTime;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
seconds = seconds % 60;
textView.setText(String.format("%d:%02d", minutes, seconds));
if (elapsedTime == -1) {
handler.postDelayed(this, 500);
}
}
public void start() {
this.startTime = System.currentTimeMillis();
this.elapsedTime = -1;
handler.post(this);
}
public void stop() {
this.elapsedTime = System.currentTimeMillis() - startTime;
handler.removeCallbacks(this);
}
public long getElapsedTime() {
return elapsedTime;
}
}
使用..只要做:
TimerTextHelper timerTextHelper = new TimerTextHelper(textView);
timerTextHelper.start();
如果你已经有时间了
public class Timer {
private float lastFrameChanged;
private float frameDuration;
private Runnable r;
public Timer(float frameDuration, Runnable r) {
this.frameDuration = frameDuration;
this.lastFrameChanged = 0;
this.r = r;
}
public void update(float dt) {
lastFrameChanged += dt;
if (lastFrameChanged > frameDuration) {
lastFrameChanged = 0;
r.run();
}
}
}
因为这个问题仍然吸引着很多谷歌搜索的用户,关于Android定时器,我想插入我的两枚硬币 首先,在Java9中该类将被弃用 建议的方法是使用更有效且功能丰富的方法,该方法可以额外安排命令在给定延迟后运行,或定期执行。此外,它还为ThreadPoolExecutor提供了额外的灵活性和功能 下面是一个使用普通功能的示例 创建执行器服务:
final ScheduledExecutorService SCHEDULER = Executors.newScheduledThreadPool(1);
只需安排您的跑步时间:
final Future<?> future = SCHEDULER.schedule(Runnable task, long delay,TimeUnit unit);
希望您会发现这对在Android中创建任务非常有用
完整示例:
ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
Future<?> sampleFutureTimer = scheduler.schedule(new Runnable(), 120, TimeUnit.SECONDS);
if (sampleFutureTimer.isDone()){
// Do something which will save world.
}
我很惊讶,没有一个答案会提到解决方案。它非常简单,并且提供了一种在Android中设置计时器的简单方法 首先,如果尚未设置渐变依赖项,则需要设置渐变依赖项:
implementation "io.reactivex.rxjava2:rxjava:2.x.y"
将x和y替换为
因为我们只有一个简单的、不重复的任务,所以我们可以使用Completable对象:
对于重复任务,您可以以类似的方式使用Observable:
Observable.interval(2, TimeUnit.SECONDS, Schedulers.computation())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(tick -> {
// called every 2 seconds, do something...
}, throwable -> {
// handle error
});
Schedulers.computation确保我们的计时器在后台线程上运行。observeOnAndroidSchedulers.mainThread意味着我们在计时器完成后运行的代码将在主线程上完成
为了避免不必要的内存泄漏,您应该确保在活动/片段被销毁时取消订阅。我将计时器提取出来,并将其作为一个单独的cla ss: Timer.java 并从Timer类中提取主操作,如下所示 java 我就是这样用的: MainActivity.java 我希望这有助于我使用这种方式:
String[] array={
"man","for","think"
}; int j;
然后在onCreate下面
TextView t = findViewById(R.id.textView);
new CountDownTimer(5000,1000) {
@Override
public void onTick(long millisUntilFinished) {}
@Override
public void onFinish() {
t.setText("I "+array[j] +" You");
j++;
if(j== array.length-1) j=0;
start();
}
}.start();
这是解决此问题的简单方法。对于想在kotlin这样做的人:
val timer = fixedRateTimer(period = 1000L) {
val currentTime: Date = Calendar.getInstance().time
runOnUiThread {
tvFOO.text = currentTime.toString()
}
}
要停止计时器,可以使用以下命令:
timer.cancel()
此函数还有许多其他选项,请尝试一下以下是解决此问题的方法,您需要在代码中添加以下类。您可以直接将视图添加到XML文件中
enter code here
Thread th=new Thread(new Runnable() {
@Override
public void run() {
try { for(int i=0;i<5;i++) {
b1.setText(""+i);
Thread.sleep(5000);
runOnUiThread(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
pp();
}
}
});
}} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
th.start();
import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;
import java.util.Locale;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;
public class TimerTextView extends TextView {
private static final int DEFAULT_INTERVAL = 1000;
private Timer timer = new Timer();
private long endTime = 0;
private long interval = DEFAULT_INTERVAL;
private boolean isCanceled = false;
public TimerTextView(Context context) {
super(context);
}
public TimerTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public TimerTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public TimerTextView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
stopTimer();
}
@Override protected void onVisibilityChanged(View changedView, int visibility) {
super.onVisibilityChanged(changedView, visibility);
if (VISIBLE == visibility) {
startTimer();
} else {
stopTimer();
}
}
public void setInterval(long interval) {
if (interval >= 0) {
this.interval = interval;
stopTimer();
startTimer();
}
}
public void setEndTime(long endTime) {
if (endTime >= 0) {
this.endTime = endTime;
stopTimer();
startTimer();
}
}
private void startTimer() {
if (endTime == 0) {
return;
}
if (isCanceled) {
timer = new Timer();
isCanceled = false;
}
timer.scheduleAtFixedRate(new TimerTask() {
@Override public void run() {
if (null == getHandler()) {
return;
}
getHandler().post(new Runnable() {
@Override public void run() {
setText(getDurationBreakdown(endTime - System.currentTimeMillis()));
}
});
}
}, 0, interval);
}
private void stopTimer() {
timer.cancel();
isCanceled = true;
}
private String getDurationBreakdown(long diff) {
long millis = diff;
if (millis < 0) {
return "00:00:00";
}
long hours = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis);
return String.format(Locale.ENGLISH, "%02d:%02d:%02d", hours, minutes, seconds);
//return "${getWithLeadZero(hours)}:${getWithLeadZero(minutes)}:${getWithLeadZero(seconds)}"
}
}
Kotlin非常简单不要这样做。有一个简单的计时器类可以为您完成这一切。这个问题与progressdialogs或dialogs完全无关。你是看了我发布的链接部分,还是只看到dialogs这个词并假设?那里的代码是100%相关的。另外,如果您使用计时器,您仍然在创建一个线程来处理更新循环。您仍然需要使用我发布的链接中描述的处理程序。不幸的是,链接页面不再包含标题为的部分。当链接到代码时,应该始终在答案中直接包含关键片段。如果你阅读了上面的文章,你就会明白为什么这不是一个理想的解决方案。OP想用TimerTask来做,我不推荐在游戏中使用。嗯?OP没有具体说明他们想怎么做。他们链接到了一篇使用TimerTask的文章,但他们没有要求这样做。帮助很多,谢谢@Friented great answer simple to follow.@Dave.B,谢谢这个好例子。与你概述的其他方法相比,使用一种方法有什么优点/缺点吗?@Gautam我相信上述所有方法的性能大致相同。我个人更喜欢上面描述的带有Runnable和h2处理程序的处理程序方法,因为它是android开发者网站规定的,在我看来也是最优雅的。最好将您喜欢的方法与代码的其余部分分开。比如,你可以用一个例子来展示你喜欢的方式,另一个例子来展示备选方案。把这三种方法放在一起会让人更难理解到底发生了什么,特别是对于像我这样的android新手。也许问得太多了:@Jesseldridge好主意。我继续添加了只使用首选方法的代码。@bluesm老实说,我只是没有考虑它,但是可以。也许一些代码缩进和代码解释会有用。伙计,ActivityTimerListener有什么问题?我的ADT包说没有这样的课程。这个课程可能会有帮助:这会有帮助。不幸的是,您的链接已断开。我无法很快找到正确的文章。为了完整起见,您可能会提到如何停止计时器,或者重新启动计时器。我在这里找到了必要的信息:有什么原因不能直接从TimerTask运行方法调用runOnUIThread吗?看起来效果很好,消除了另一个层次的嵌套。当然,这只是一个教诲式的方法来理解所有步骤。我建议这个标准应该有一个可读的代码。只有当你知道你希望它在几次执行后消失时,倒计时才有意义。这不是一种典型的、也不是特别灵活的方法。更常见的是计时器会永远重复,不再需要时会取消,或者处理程序会运行一次,然后在需要时再次启动。看看其他答案,你完全正确。从类名开始,它提供一个倒计时计时器,直到完成,当然它在实现中使用了处理程序。如何显示毫秒?以SS:MiMi的格式?谢谢,我看到你在最初的问题和答案之后的几年里添加了这个。请添加此答案与已有其他答案的比较说明。为什么你要添加另一个-在其他答案中你看到了什么好处/什么时候有用/什么缺点?我只是分享了一个代码,它用不同的方法做相同的工作。但只要您想更新任何视图的数据。您必须为它使用处理程序。因为很多时候我都注意到使用timertask更新视图是行不通的@据我所知,Dave.B方法更为正确。为什么要采用这种笨拙的方法,而不是像其他人一样在onPause中删除回调?这是最干净的方法!如何取消这些?i、 e.当用户按下UI上的[STOP]按钮,并且在执行之前取消Completable时。@某个地方的某个人只需将.subscribe方法返回的订阅保存在变量中,然后在要停止计时器时调用Subscription.unsubscribe。如果我们只想使用该计时器对象在04:00运行该怎么办?
Observable.interval(2, TimeUnit.SECONDS, Schedulers.computation())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(tick -> {
// called every 2 seconds, do something...
}, throwable -> {
// handle error
});
import android.os.Handler;
public class Timer {
IAction action;
Handler timerHandler = new Handler();
int delayMS = 1000;
public Timer(IAction action, int delayMS) {
this.action = action;
this.delayMS = delayMS;
}
public Timer(IAction action) {
this(action, 1000);
}
public Timer() {
this(null);
}
Runnable timerRunnable = new Runnable() {
@Override
public void run() {
if (action != null)
action.Task();
timerHandler.postDelayed(this, delayMS);
}
};
public void start() {
timerHandler.postDelayed(timerRunnable, 0);
}
public void stop() {
timerHandler.removeCallbacks(timerRunnable);
}
}
public interface IAction {
void Task();
}
public class MainActivity extends Activity implements IAction{
...
Timer timerClass;
@Override
protected void onCreate(Bundle savedInstanceState) {
...
timerClass = new Timer(this,1000);
timerClass.start();
...
}
...
int i = 1;
@Override
public void Task() {
runOnUiThread(new Runnable() {
@Override
public void run() {
timer.setText(i + "");
i++;
}
});
}
...
}
String[] array={
"man","for","think"
}; int j;
TextView t = findViewById(R.id.textView);
new CountDownTimer(5000,1000) {
@Override
public void onTick(long millisUntilFinished) {}
@Override
public void onFinish() {
t.setText("I "+array[j] +" You");
j++;
if(j== array.length-1) j=0;
start();
}
}.start();
val timer = fixedRateTimer(period = 1000L) {
val currentTime: Date = Calendar.getInstance().time
runOnUiThread {
tvFOO.text = currentTime.toString()
}
}
timer.cancel()
enter code here
Thread th=new Thread(new Runnable() {
@Override
public void run() {
try { for(int i=0;i<5;i++) {
b1.setText(""+i);
Thread.sleep(5000);
runOnUiThread(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
pp();
}
}
});
}} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
th.start();
import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;
import java.util.Locale;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;
public class TimerTextView extends TextView {
private static final int DEFAULT_INTERVAL = 1000;
private Timer timer = new Timer();
private long endTime = 0;
private long interval = DEFAULT_INTERVAL;
private boolean isCanceled = false;
public TimerTextView(Context context) {
super(context);
}
public TimerTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public TimerTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public TimerTextView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
stopTimer();
}
@Override protected void onVisibilityChanged(View changedView, int visibility) {
super.onVisibilityChanged(changedView, visibility);
if (VISIBLE == visibility) {
startTimer();
} else {
stopTimer();
}
}
public void setInterval(long interval) {
if (interval >= 0) {
this.interval = interval;
stopTimer();
startTimer();
}
}
public void setEndTime(long endTime) {
if (endTime >= 0) {
this.endTime = endTime;
stopTimer();
startTimer();
}
}
private void startTimer() {
if (endTime == 0) {
return;
}
if (isCanceled) {
timer = new Timer();
isCanceled = false;
}
timer.scheduleAtFixedRate(new TimerTask() {
@Override public void run() {
if (null == getHandler()) {
return;
}
getHandler().post(new Runnable() {
@Override public void run() {
setText(getDurationBreakdown(endTime - System.currentTimeMillis()));
}
});
}
}, 0, interval);
}
private void stopTimer() {
timer.cancel();
isCanceled = true;
}
private String getDurationBreakdown(long diff) {
long millis = diff;
if (millis < 0) {
return "00:00:00";
}
long hours = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis);
return String.format(Locale.ENGLISH, "%02d:%02d:%02d", hours, minutes, seconds);
//return "${getWithLeadZero(hours)}:${getWithLeadZero(minutes)}:${getWithLeadZero(seconds)}"
}
}
import kotlin.concurrent.fixedRateTimer
val timer = fixedRateTimer("Tag", false, 1000, 2500) { /* Your code here */ }