Fragment与Activity交互方式使用Handler

• 第一步、在Activity定义一个接收handler的方法，getHandler()

public void getHandler(Handler handler) {
mHandler = handler;
}

• 第二步、在Fragment函数onAttach()中得到Fragment所依附Activity，并调用getHandler()方法，把Handler传给activity。该Handler在Fragment中创建，用来接收消息与Fragment进行交互。

       @Override
    public void onAttach(Context context) {
       super.onAttach(context);
        Activity activity = getActivity();
        mActivity = (MainActivity) activity;
        mActivity.getHandler(mHandler);}
    public Handler mHandler = new Handler() {
         @Override
          public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case 1:
                    text.setText((String) msg.obj);
                    break;
            }
        }
    };

• 第三步、在Activity给Fragment发消息

       public void click（View v）｛
        Message msg = new Message();
        msg.obj = edit.getText().toString();
        msg.what = 1;
        mHandler.sendMessage(msg);
        ｝