android基本定時器和延時的用法,總結(jié)一下比較簡潔的模式,方便簡單地在程序中直接調(diào)用。
一、定時循環(huán)
1. handler.postDelayed+Runnable
- 首先創(chuàng)建一個Handler對象
Handler handler=new Handler();
- 然后創(chuàng)建一個Runnable對象
Runnable runnable=new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
//要做的事情,這里再次調(diào)用此Runnable對象,以實現(xiàn)每兩秒實現(xiàn)一次的定時器操作
handler.postDelayed(this, 2000);
}};
- 主線程中調(diào)用,使用PostDelayed方法,兩秒后調(diào)用此Runnable對象
handler.postDelayed(runnable, 2000);
- ★ 關(guān)閉此定時器,可以這樣操作
handler.removeCallbacks(runnable);
2. handler+timer+timeTask
- 首先創(chuàng)建一個Handler對象
Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (msg.what == 1){
//do something
}
super.handleMessage(msg);
}
};
- 然后創(chuàng)建一個Timer 對象
Timer timer = new Timer();
TimerTask timerTask = new TimerTask() {
@Override
public void run() {
Message message = new Message();
message.what = 1;
handler.sendMessage(message);
}
};
- 主線程中調(diào)用,使用schedule方法
//延時1s,每隔500毫秒執(zhí)行一次run方法
timer.schedule(timerTask,1000,500);
3. Thread+handler
- 首先創(chuàng)建一個Handler對象
Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (msg.what == 1){
//do something
}
super.handleMessage(msg);
}
};
- 然后創(chuàng)建一個Timer 對象
class ScheduleThread extends Thread {//這里也可用Runnable接口實現(xiàn)
@Override
public void run() {
while (true){
try {
//每隔1s執(zhí)行一次
Thread.sleep(1000);
Message msg = new Message();
msg.what = 1;
handler.sendMessage(msg);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
- 主線程中調(diào)用
new Thread(new ScheduleThread ()).start();
二、延時
1. Handler的postDelayed方法:
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
//do something
}
}, 1000); //延時1s執(zhí)行
2. Timer + TimerTask方法:
timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
//do something
}
},1000);//延時1s執(zhí)行
3. Thread方法:
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(1000);//延時1s
//do something
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}).start();
new Thread(new MyThread()).start();