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 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"/>

这是一个定时器的简单代码:

Timer timer = new Timer();
TimerTask t = new TimerTask() {       
    @Override
    public void run() {

        System.out.println("1");
    }
};
timer.scheduleAtFixedRate(t,1000,1000);

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

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();

如果你已经有了时间。

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();
        }
    }
}