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();

这里是解决方案，您需要在代码中添加以下类。您可以直接向XML文件添加视图。

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 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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context=".MainActivity" >

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:autoLink="web"
    android:text="http://android-er.blogspot.com/"
    android:textStyle="bold" />
<CheckBox 
    android:id="@+id/singleshot"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Single Shot"/>

这里有一个简单可靠的方法…

将以下代码放入Activity中，当Activity处于“恢复”状态时，tick()方法将在UI线程中每秒调用一次。当然，您可以更改tick()方法来做您想做的事情，或者更频繁地调用它。

@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=_handler”代码是必要的，以避免在tick周期内暂停和恢复活动时同时运行两个计时器。

我认为你可以用Rx方法来做:

 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
                }
            });

然后取消这个:

timerSubscribe.unsubscribe();

接收定时器 http://reactivex.io/documentation/operators/timer.html

我用这种方法:

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();

解决这个问题很简单。