实现Android计时与倒计时方法

今天给大家介绍几个Android中实现计时和倒计时的几种方法，这几种方法也许今后会帮上大家，现贴出来如下：

方法一

Timer与TimerTask（Java实现）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 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）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 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）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 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）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 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）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 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

http://www.itivy.com/android/archive/2011/10/25/some-method-android-timer.html

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