【内存泄漏】Android内存泄漏---Handler

Handler咱们常常用在程序中，发送消息，然而这里涉及到内存泄漏隐患，非静态内部类引发的。

非静态内部类引发内存泄漏，详见http://blog.csdn.net/qq_29266921/article/details/54847402

举个栗子：

public class MainActivity extends AppCompatActivity {

    private Handler mHandler = new Handler() {

        @Override

        public void handleMessage(Message msg) {

            //...

        }

    };

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        loadData();

    }

    private void loadData(){

        //...request

        Message message = Message.obtain();

        mHandler.sendMessage(message);

    }

}

建议去看上面的连接，而后你就会知道非静态匿名内部类，和非静态内部类引发内存泄漏缘由是同样的。

上面的代码能够更加安全，修改以下：

public class MainActivity extends AppCompatActivity {

    private MyHandler mHandler = new MyHandler(this);

    private TextView mTextView ;

    private static class MyHandler extends Handler {

        private WeakReference<Context> reference;

        public MyHandler(Context context) {

            reference = new WeakReference<>(context);

        }

        @Override

        public void handleMessage(Message msg) {

            MainActivity activity = (MainActivity) reference.get();

            if(activity != null){

                activity.mTextView.setText("");

            }

        }

    }

  

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mTextView = (TextView)findViewById(R.id.textview);

        loadData();

    }

  

    private void loadData() {

        //...request

        Message message = Message.obtain();

        mHandler.sendMessage(message);

    }

  

    @Override

    protected void onDestroy() {

        super.onDestroy();

        mHandler.removeCallbacksAndMessages(null);

    }

}

1.建立一个静态Handler内部类，而后对Handler持有的对象使用弱引用，这样在回收时也能够回收Handler持有的对象。

2.mHandler.removeCallbacksAndMessages(null)移除消息队列中全部消息和全部的Runnable。固然也能够使用mHandler.removeCallbacks()或mHandler.removeMessages()来移除指定的Runnable和Message