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 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; 实现方式比较 方法1,采用的是Java实现,即Timer和TimerTask方式; 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 希望本文所述对大家Android程序设计有所帮助。 |