Android中使用定时器的三种方法

Runnable runnable = new Runnable() {
  @Override
 public void run() {
  while (true) {
  mHandler.sendEmptyMessage(0);
 try {
  Thread.sleep(1000);
 } catch (InterruptedException e) {
  e.printStackTrace();
   }
   }
  }
  };
new Thread(runnable).start();
}

final Runnable runnable = new Runnable() {
   @Override
   public void run() {
    if (isStart2) {
     mHandler.sendEmptyMessage(0);
     mHandler.postDelayed(this, 1000);
    }
   }
  };
mHandler.postDelayed(runnable, 1000);
  }

 private Timer timer = new Timer();
 private TimerTask timerTask = new TimerTask() {
  @Override
  public void run() {
   mHandler.sendEmptyMessage(0);
  }
 };
 timer.schedule(timerTask, 1000, 1000);

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
 tools:context="com.brioal.timertest.MainActivity">

 <TextView
  android:id="@+id/main_tv"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerHorizontal="true"
  android:layout_marginTop="100dp"
  android:text="Hello World!" />

 <LinearLayout
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:layout_below="@id/main_tv"
  android:layout_marginTop="100dp"
  android:gravity="center"
  android:orientation="vertical">

  <Button
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_gravity="center"
   android:layout_margin="5dp"
   android:onClick="Method1"
   android:text="方法1:Thread"
   android:textAllCaps="false" />

  <Button
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_gravity="center"
   android:layout_margin="5dp"
   android:onClick="Method2"
   android:text="方法2:Handler"
   android:textAllCaps="false" />

  <Button
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_gravity="center"
   android:layout_margin="5dp"
   android:onClick="Method3"
   android:text="方法3:Task"
   android:textAllCaps="false" />
 </LinearLayout>
</RelativeLayout>

package com.brioal.timertest;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Timer;
import java.util.TimerTask;

public class MainActivity extends AppCompatActivity {
 private TextView mTv;
 private Handler mHandler = new Handler() {
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   //收到消息后显示当前时间
   long current = System.currentTimeMillis();
   SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
   String time = dateFormat.format(current);
   mTv.setText(time);
  }
 };
 private Timer timer = new Timer();
 private TimerTask timerTask = new TimerTask() {
  @Override
  public void run() {
   mHandler.sendEmptyMessage(0);
  }
 };
 private Thread thread1;
 private boolean isStart1 = false;
 private boolean isStart2 = false;
 private boolean isStart3 = false;


 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  mTv = (TextView) findViewById(R.id.main_tv);
 }

 //Thread方法
 public void Method1(View view) {
  Runnable runnable = new Runnable() {
   @Override
   public void run() {
    while (isStart1) {
     mHandler.sendEmptyMessage(0);
     try {
      Thread.sleep(1000);

     } catch (InterruptedException e) {
      e.printStackTrace();
     }
    }

   }
  };
  if (isStart1) {
   isStart1 = false;
  } else {
   isStart1 = true;
   thread1 = new Thread(runnable);
   thread1.start();
  }
 }

 public void Method2(View view) {

  final Runnable runnable = new Runnable() {
   @Override
   public void run() {
    if (isStart2) {
     mHandler.sendEmptyMessage(0);
     mHandler.postDelayed(this, 1000);
    }
   }
  };
  if (isStart2) {
   isStart2 = false;
  } else {
   mHandler.postDelayed(runnable, 1000);
   isStart2 = true;
  }
 }

 public void Method3(View view) {
  if (isStart3) {
   timer.cancel();
   isStart3 = false;
  } else {
   timer.schedule(timerTask, 1000, 1000);
   isStart3 = true;
  }
 }
}