Android移动应用基础教程 【程序活动单元Activity】(2)

Intent intent = new Intent(MainActivity.this,SecondActivity.class);
        startActivityForResult(intent,1);
        //使用startActivityForResult方法开启SecondActivity，第1个参数是Intent对象，第2个参数是请求码，用于标识请求的来源。

Intent intent = new Intent();
        intent.putExtra("data","Hello MainActivity");
        setResult(2,intent);//在SecondActivity 中添加返回数据。
        finish();

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {// SecondActivity被销毁之后在MainActivity中回调onActivityResult()方法。
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 1&&resultCode == 2){
        String acquiredData= data.getStringExtra("data"); //获取回传的数据
        Toast.makeText(MainActivity.this,acquiredData,Toast.LENGTH_SHORT).show();
    }
}

NewsListFragment fragment = new NewsListFragment();//实例化Fragment对象
FragmentManager fm = getFragmentManager();//获取FragmentManager实例
FragmentTransaction beginTransaction = fm.beginTransaction();//开启事务
beginTransaction.replace(R.id.ll,fragment); //添加Fragment
beginTransaction.commit();//提交事务