handler ：更新UI的机制，消息的处理机制
四种用法sendMessage、sendMessageDelayed、post(runnable)、postDelayed(Runnable,long)
post用法
private android.os.Handler handler = new android.os.Handler();
new Thread() {
public void run() {
try {
Thread.sleep(1000);
handler.post(new Runnable() {
@Override
public void run() {
text.setText("123");
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}.start();
sendMessage用法
private android.os.Handler handler = new android.os.Handler() {
@Override
public void handleMessage(Message msg) {
text.setText("" + msg.arg1);
}
};
new Thread() {
@Override
public void run() {
try {
Thread.sleep(1000);
Message message = new Message();
message.arg1 = 100;
//handler.sendMessage(XXX);对象可以是int，也可以是obj对象
//message.obj=Person; Person是一个实体类对象
handler.sendMessage(message);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}.start();
handler.postDelayed(task,time);可以作为viewpager的图片自动切换
private android.os.Handler handler = new android.os.Handler();
private Myrunnable myrunnable = new Myrunnable(); class Myrunnable implements Runnable { @Override public void run() {
//做需要循环的操作 handler.postDelayed(myrunnable, 1000); } }
handler.postDelayed(myrunnable,1000);//调用
handler.removeCallbacks(myrunnable);//移除原文：http://www.cnblogs.com/lyxin/p/5731259.html