Android实现定时器的方法
16lz
2021-01-23
一、Handler 和 Thread
package com.lstech.app;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.widget.TextView;/** * handler定时器 * * */public class HandlerActivity extends Activity { TextView tvShow; private int i = 0; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tvShow = (TextView) findViewById(R.id.tv_show); new Thread(new ThreadShow()).start(); } // handler类接收数据 Handler handler = new Handler() { public void handleMessage(Message msg) { if (msg.what == 1) { tvShow.setText(Integer.toString(i++)); System.out.println("receive...."); } }; }; // 线程类 class ThreadShow implements Runnable { @Override public void run() { // TODO Auto-generated method stub while (true) { try { Thread.sleep(1000); Message msg = new Message(); msg.what = 1; handler.sendMessage(msg); System.out.println("send..."); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); System.out.println("thread error..."); } } } }}
二、Handler的postDelyed方法
package com.lstech.app;
import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.widget.TextView;/** * handler定时器使用postDelyed实现 * */public class postDelyedActivity extends Activity { TextView tvShow; private int i = 0; private int DELYED= 1000; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tvShow = (TextView) findViewById(R.id.tv_show); handler.postDelayed(runnable, DELYED); //每隔1s执行 } Handler handler = new Handler(); Runnable runnable = new Runnable() { @Override public void run() { // handler自带方法实现定时器 try { handler.postDelayed(this, DELYED); tvShow.setText(Integer.toString(i++)); System.out.println("do..."); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); System.out.println("exception..."); } } };}
三、Handler + Timer + TimerTask
package com.lstech.app;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.widget.TextView;/** * 定时器实现 * * */public class TimerActivity extends Activity { TextView tvShow; private int i = 0; private int TIME = 1000; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tvShow = (TextView) findViewById(R.id.tv_show); timer.schedule(task, 1000, 1000); // 1s后执行task,经过1s再次执行 } Handler handler = new Handler() { public void handleMessage(Message msg) { if (msg.what == 1) { tvShow.setText(Integer.toString(i++)); } super.handleMessage(msg); }; }; Timer timer = new Timer(); TimerTask task = new TimerTask() { @Override public void run() { // 需要做的事:发送消息 Message message = new Message(); message.what = 1; handler.sendMessage(message); } };}
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