返回到上一个Activity

startActivityForResult(intent,requestCode);
onActivityResult(int requestCode,int resultCode,Intent data){}
//第二个Activity
setResult(RESULT_OK,intent);
finish();

//一般在onStop()之前调用
onSaveInstanceState(Bundle outState){
super.onSaveInstanceState(outState);
String tempData = "Something you just typed";
outState.putString("data_key",tempData);
}

protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
if(savedInstanceState!=null){
String tempData = savedInstanceState.getString("data_key");
Log.d(TAG,tempData);
}
}