如何放置额外的数组列表 <object> 与if语句并在其他活动中显示

Question

Activiy 1

List<Goods> goodsList = new ArrayList<>();
goodsList = getAllData();
Goods goods = new goods();
intent.putExtra("listbarang", (Serializable) goodsList);

function getAllData() is my function to show all data in my database, and I show it with RecyclerView by the way.

Activity 2

goodsList = (List<Goods>) getIntent().getSerializableExtra("listbarang");

and there's how I get the ArrayList

all I want is put extra the ArrayList with the specific condition with if statement. For example, I want to show only the goodies who have stock more than 0.

I have succeeded to store the ArrayList. But I want to get specific data for that condition, maybe using looping or something else.

Answer 1

I don't quite understand with your question, I think you probably need to pass the criteria with the list. Something like this:

intent.putExtra("listbarang", goodsList);
// Criteria for at least one item in the list
intent.putExtra("criteria", 1);

Then process the extra:

int criteria;

Intent intent = getIntent();
goodsList = (List<Goods>) intent.getSerializableExtra("listbarang");
criteria = intent.getIntExtra("criteria", 0);

// do something based on criteria
for(Goods good: goodsList) {
  if(good.getStock >= criteria) {
    // process the good.
  }
}

Answer 2

您可以从Parcelable实现商品类，并使用Bundle.putParcelableArrayList存储列表数据。

Answer 3

Solution for passing arrayList between activities, fragment and storing them in sharedPreferences.

Passing arrayList of Object type from One Activity to another activity.

This solution will also used for passing from one fragment to another fragment

or fragment to activity or activity to fragment.

And this also helps to store arrayList of object type in sharedPreferences.

First added this dependency in build.gradle(app) file


compile 'com.google.code.gson:gson:2.4'


for e.g.:

//first Activity
ArrayList<Goods> list=new ArrayList<>();
Gson gson=new Gson();
String goodList=gson.toJson(list);
Intent intent=new Intent(this,SecondActivity.class);
intent.putString("goods",goodList);
startActivity();


//Second Activity
Gson gson=new Gson();
String goodList=getIntent().getString("goods");
Type type=new TypeToken<ArrayList<Goods>>(){}.getType();
List<Goods> list = new gson.fromJson(goodList,type);

I hope this solution will help you. Thanks