內部Handler類引起的記憶體泄露與This Handler class should be static or lea

我們可以找到這樣一個變化：

public class MainActivity extends Activity {     private  Handler mHandler = newHandler() {        @Override        public void handleMessage(Message msg) {            //TODO handle message...        }     };     @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mHandler.sendMessageDelayed(Message.obtain(), 60000);         //just finish this activity        finish();    }}

    然後運行Android Lint工具會有一個記憶體泄露警告:This Handler class should be static or leaks might occur。

    要修改該問題，只需要按照Lint提示的那樣，把Handler類定義為靜態即可，然後通過WeakReference 來保持外部的Activity對象。

private Handler mHandler = new MyHandler(this);private static class MyHandler extendsHandler{    private final WeakReference<Activity> mActivity;    public MyHandler(Activity activity) {        mActivity = newWeakReference<Activity>(activity);    }    @Override    public void handleMessage(Message msg) {        System.out.println(msg);        if(mActivity.get() == null) {            return;        }    }}

 所以，當你在Activity中使用內部類的時候，需要時刻考慮您是否可以控制該內部類的生命週期，如果不可以，則最好定義為靜態內部類。