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
