Android实现计时与倒计时的常用方法小结_安卓软件开发教程-查字典教程网
Android实现计时与倒计时的常用方法小结
Android实现计时与倒计时的常用方法小结
发布时间:2016-12-28 来源:查字典编辑
摘要:本文实例总结了Android实现计时与倒计时的常用方法。分享给大家供大家参考,具体如下:方法一Timer与TimerTask(Java实现)...

本文实例总结了Android实现计时与倒计时的常用方法。分享给大家供大家参考,具体如下:

方法一

Timer与TimerTask(Java实现)

public class timerTask extends Activity{ private int recLen = 11; private TextView txtView; Timer timer = new Timer(); public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.timertask); txtView = (TextView)findViewById(R.id.txttime); timer.schedule(task, 1000, 1000); // timeTask } TimerTask task = new TimerTask() { @Override public void run() { runOnUiThread(new Runnable() { // UI thread @Override public void run() { recLen--; txtView.setText(""+recLen); if(recLen < 0){ timer.cancel(); txtView.setVisibility(View.GONE); } } }); } }; }

方法二

TimerTask与Handler(不用Timer的改进型)

public class timerTask extends Activity{ private int recLen = 11; private TextView txtView; Timer timer = new Timer(); public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.timertask); txtView = (TextView)findViewById(R.id.txttime); timer.schedule(task, 1000, 1000); // timeTask } final Handler handler = new Handler(){ @Override public void handleMessage(Message msg){ switch (msg.what) { case 1: txtView.setText(""+recLen); if(recLen < 0){ timer.cancel(); txtView.setVisibility(View.GONE); } } } }; TimerTask task = new TimerTask() { @Override public void run() { recLen--; Message message = new Message(); message.what = 1; handler.sendMessage(message); } }; }

方法三

Handler与Message(不用TimerTask)

public class timerTask extends Activity{ private int recLen = 11; private TextView txtView; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.timertask); txtView = (TextView)findViewById(R.id.txttime); Message message = handler.obtainMessage(1); // Message handler.sendMessageDelayed(message, 1000); } final Handler handler = new Handler(){ public void handleMessage(Message msg){ // handle message switch (msg.what) { case 1: recLen--; txtView.setText("" + recLen); if(recLen > 0){ Message message = handler.obtainMessage(1); handler.sendMessageDelayed(message, 1000); // send message }else{ txtView.setVisibility(View.GONE); } } super.handleMessage(msg); } }; }

方法四

Handler与Thread(不占用UI线程)

public class timerTask extends Activity{ private int recLen = 0; private TextView txtView; public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.timertask); txtView = (TextView)findViewById(R.id.txttime); new Thread(new MyThread()).start(); // start thread } final Handler handler = new Handler(){ // handle public void handleMessage(Message msg){ switch (msg.what) { case 1: recLen++; txtView.setText("" + recLen); } super.handleMessage(msg); } }; public class MyThread implements Runnable{ // thread @Override public void run(){ while(true){ try{ Thread.sleep(1000); // sleep 1000ms Message message = new Message(); message.what = 1; handler.sendMessage(message); }catch (Exception e) { } } } } }

方法五

Handler与Runnable(最简单型)

public class timerTask extends Activity{ private int recLen = 0; private TextView txtView; public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.timertask); txtView = (TextView)findViewById(R.id.txttime); handler.postDelayed(runnable, 1000); } Handler handler = new Handler(); Runnable runnable = new Runnable() { @Override public void run() { recLen++; txtView.setText("" + recLen); handler.postDelayed(this, 1000); } }; }

计时与倒计时

方法1,方法2和方法3,都是倒计时

方法4,方法5,都是计时

计时和倒计时,都可使用上述方法实现(代码稍加改动)

UI线程比较

方法1,方法2和方法3,都是在UI线程实现的计时;

方法4和方法5,是另开Runnable线程实现计时

实现方式比较

方法1,采用的是Java实现,即Timer和TimerTask方式;

其它四种方法,都采用了Handler消息处理

推荐使用

如果对UI线程交互要求不很高,可以选择方法2和方法3

如果考虑到UI线程阻塞,严重影响到用户体验,推荐使用方法4,另起线程单独用于计时和其它的逻辑处理

方法5,综合了前几种方法的优点,是最简的

希望本文所述对大家Android程序设计有所帮助。

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