How to write List<> into parcel

Question

public class Category implements Parcelable {

    private int mCategoryId;
    private List<Video> mCategoryVideos;

 public int getCategoryId() {
        return mCategoryId;
    }

    public void setCategoryId(int mCategoryId) {
        this.mCategoryId = mCategoryId;
    }

 public List<Video> getCategoryVideos() {
        return mCategoryVideos;
    }

    public void setCategoryVideos(List<Video> videoList) {
        mCategoryVideos = videoList;
    }

@Override
    public void writeToParcel(Parcel parcel, int i) {
        parcel.writeInt(mCategoryId);
        parcel.writeTypedList(mCategoryVideos);
    }

    public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {
        public Category createFromParcel(Parcel parcel) {
            final Category category = new Category();

            category.setCategoryId(parcel.readInt());
            category.setCategoryVideos(parcel.readTypedList()); */// **WHAT SHOULD I WRITE HERE***

            return category;
        }

        public Category[] newArray(int size) {
            return new Category[size];
        }
    };

}

Im my code I am using model which implements from parcelable...Could anyone tell em what shout I write in this line category.setCategoryVideos(parcel.readTypedList()) I couldn't find any helpful post.

EDIT: category.setCategoryVideos(parcel.readTypedList(mCategoryVideos,Video.CREATOR)); in here mCategoryVideos I have cannot resolve error.

score 36 · Accepted Answer · edited Jun 29 '17 at 08:04

36

There are list methods for Parcelable class, you can take a look at them here:

readList (List outVal, ClassLoader loader)

writeList (List val)

In your case it would look like:

List<Object> myList = new ArrayList<>();

parcel.readList(myList,List.class.getClassLoader());
category.setCategoryVideos(myList);

edited Jun 29 '17 at 08:04

Sarah Sukardi

45
1
8

answered Mar 21 '13 at 09:37

Brosa

1,169
9
19

2

This answer should be marked as correct, one thing tho is that the List must contain Parcelable objects as well. – Mokkun Mar 25 '14 at 07:13
5

Very minor correction: `parcel.readList(myList, ElementType.class.getClassLoader());` – WindRider Jul 29 '16 at 17:00
3

NullPointerException – Pablo Cegarra Jun 20 '17 at 11:21

score 6 · Answer 2 · answered Jun 20 '17 at 11:28

6

From a good answer:

Easy steps:

private List<MyParcelableClass> mList;

protected MyClassWithInnerList(Parcel in) {
    mList = in.readArrayList(MyParcelableClass.class.getClassLoader());
}
@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeList(mList);
}

answered Jun 20 '17 at 11:28

Pablo Cegarra

20,955
12
92
110

2

When reading list from parcelable it is better to use `in.readList(myList, MyParcelableClass.class.getClassLoader());` – Wojtek Sep 06 '17 at 20:21

score 2 · Answer 3 · edited Jan 30 '18 at 10:26

public static final Parcelable.Creator<Category> CREATOR = new Parcelable.Creator<Category>() {
            public Category createFromParcel(Parcel in) {
                return new Category(in);
            }

            public Category[] newArray(int size) {
                return new Category[size];
            }
        };

private Category(Parcel in) {
    String[] data = new String[1];
    in.readStringArray(data);
    mCategoryId = Integer.parseInt(data[0]);
}

public void writeToParcel(Parcel dest, int flags) {
    dest.writeStringArray(new String[]{
            mCategoryId
    });
}

Then In ur Activity.

public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelableArrayList("mCategoryVideos", (List<? extends Parcelable>) mCategoryVideos);
}

public void onRestoreInstanceState(Bundle inState) {
    super.onRestoreInstanceState(inState);
    if (inState != null) {
        mCategoryVideos = inState.getParcelableArrayList("mCategoryVideos");
        // Restore All Necessary Variables Here
    }
}

How to write List<> into parcel

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