Kong Jing

Handler的使用

26 November 2017

Handler class should be static or leaks might occur Android

Handler类应该是static类型，否则有可能造成泄露。

public class MyHandler extends Handler{
        WeakReference<Activity> mActivity;
        
        MyHandler(Activity activity){
            mActivity = new WeakReference<Activity>(activity);
        }
        
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Activity activity = mActivity.get();
            if (activity == null){
                return;
            }
            switch (msg.what) {
                default:break;
            }
        }
    }

Activity会被gc掉，如果Activity被回收掉，那么Handler应该在使用之前对其状态进行判断，这样就不会发生空指针。

— Kong Jing