Android Handler 内存泄漏，文末消息机制的小总结

1. 内存泄漏的Activity

public class MainActivity extends AppCompatActivity {

  private static final int MESSAGE_TYPE1 = 10;
  private Button mBtnSendMessage;
  private TextView mTvShow;
  private Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
      switch (msg.what) {
        case MESSAGE_TYPE1:
          mTvShow.setText("hhh");
          break;

      }
    }
  };

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mBtnSendMessage = findViewById(R.id.btn_go_second);
    mTvShow = findViewById(R.id.tv_show);
    mBtnSendMessage.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Message msg = Message.obtain();
        msg.what = MESSAGE_TYPE1;
      // 直接发送，没啥问题
        mHandler.sendMessage(msg);
      //   延迟发送，如果Activity已经销毁，内存泄漏
        mHandler.sendMessageDelayed(msg,1000*60*5);
      }
    });
  }
}

分析：Main线程中 有一个Message 持有者Handler的引用，而且Handler