android计时器 message+handler; timer+timertask-优快云博客

本文介绍两种在Android应用中实现倒计时的方法：使用message与handler机制，以及利用timer与timertask。这两种方法均可实现在界面上显示剩余时间并进行递减更新。

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方法一：message+handler

package com.time; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.widget.TextView; public class timer extends Activity { private int recLen = 11; private TextView recTime; Handler handler = new Handler(){ public void handleMessage(Message msg) { switch (msg.what) { case 1: recLen--; recTime.setText(""+recLen); if(recLen > 0){ // Message message = Message.obtain(); // message.what = 1; Message message = handler.obtainMessage(1); handler.sendMessageDelayed(message, 1000); }else{ recTime.setVisibility(View.GONE); } break; } super.handleMessage(msg); } }; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); recTime = (TextView)findViewById(R.id.time); Message message = handler.obtainMessage(1); handler.sendMessageDelayed(message, 1000); } }

方法二：timer+timertask

package com.tim; import java.util.Timer; import java.util.TimerTask; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.TextView; public class timer1 extends Activity { private int recLen = 11; private TextView recTime; Timer timer = new Timer();; TimerTask task = new TimerTask(){ public void run() { recLen--; //修改界面的相关设置只能在UI线程中执行 runOnUiThread(new Runnable(){ public void run() { recTime.setText(""+recLen); if(recLen<0){ timer.cancel(); recTime.setVisibility(View.GONE); } }}); } }; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); recTime = (TextView)findViewById(R.id.time); timer.schedule(task,1000, 1000); } }