Android線程安全問(wèn)題：
button2.setOnClickListener(new OnClickListener() {
......
});
加了個(gè)監(jiān)聽(tīng)，里面起Timer，定時(shí)修改數(shù)據(jù)。
發(fā)現(xiàn)Log一直在打，View無(wú)變化。
估計(jì)線程出了問(wèn)題。類(lèi)似Swing的線程安全問(wèn)題。
接著Google.....
The best thing is to use Handler with delayed messages.
And Timer works fine, the problem is that a Timer runs in a separate
thread,
and so you are trying to modify a view owned by another thread (the
main
thread that originally created it).
What I think is happening is you're falling off the UI thread. There
is a single "looper" thread which handles all screen updates. If you
attempt to call "invalidate()" and you're not on this thread nothing
will happen.
Try using "postInvalidate()" on your view instead. It'll let you
update a view when you're not in the current UI thread.
解決辦法和我預(yù)計(jì)的一樣：
1.在Invalidate處調(diào)用 postInvalidate，命名上可以參數(shù)肯定是把當(dāng)前的timer線程排隊(duì)到UI線程去。不過(guò)對(duì)于我不是很適用，畢竟UI不希望讓用戶自己去Invalidate
2.既然不能去排隊(duì)，那就干脆把自己改造成UI線程吧。借助android.os.Handler
final Handler handler = new Handler();
Timer timer = new Timer();
timer.schedule(new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
root.setName(new Date() + "Root+" );//不一定是顯式的調(diào)用修改UI的語(yǔ)句
}
});
}
},1000,3000);
OK!