handler,主要接受子线程发送的数据, 并用此数据配合主线程更新UI。
//初始化定义几种消息,不同的消息刷新不同的UIprivate final static int PROGRESS_CHANGED = 0; private final static int PROGRESS_STOP = 1; //定义handler,刷新UIHandler myHandler = new Handler(){ @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub switch(msg.what){ case PROGRESS_CHANGED: //... //收到PROGRESS_CHANGED时刷新UI //每1000ms sendEmptyMessageDelayed(PROGRESS_CHANGED, 1000); break; case PROGRESS_STOP //... //收到PROGRESS_STOP 时刷新UI //每2000ms sendEmptyMessageDelayedPROGRESS_STOP 2000); break; } super.handleMessage(msg); } };
Handler运行在主线程中(UI线程中),它与子线程可以通过Message对象来传递数据:
(1)子线程发送消息
myHandler.sendEmptyMessage(PROGRESS_CHANGED);
(2)取消消息发送
myHandler.removeMessages(PROGRESS_CHANGED);