如何保存在onSaveInstanceState上实现接口的列表

Question

I have in my Activity :

List<IntManager> mt;
this.mt = new ArrayList<IntManager>();

Inside the mt list I have Objects that implement IntManager Interface, but they are let say type of Point (my custom class)

Now I want to save the this.mt in the onSaveInstanceState (Bundle outState) and restore it on onRestoreInstanceState

How should I save it? Do IntManager have to implement Parcelable or my custom class Point ? or any other?

Answer 1

是的，无论是IntManager和其使用的所有的成员字段必须实现Parcelable这样他们就可以被保存在Bundle 。

Answer 2

Yes, you could do it by implementing Parcelable and save them to the bundle

or you could use a Json serializer to seriazlize the list of custom objects to a json string and save the string to the bundle. For example, using GSon you could do it this way

java.lang.reflect.Type type = new com.google.gson.reflect.TypeToken<List<IntManager>>(){}.getType();
@Override
public void onSaveInstanceState(Bundle outState) {
   super.onSaveInstanceState(outState);
   String json = new Gson().toJson(mt, type);
   outState.putString("message", json);
}

and you can restore the instancestate from bundle

List<IntManager> test=new Gson().fromJson(savedInstanceState.getString("message"), type);

hope this helps..