使用 Parcelable 将 List<Object> 保存到实例状态

Question

我有以下型号：

GitItem:

    public class GitItem implements Serializable, Parcelable {
        public int id;
        public String name;
        public String full_name;
        public GitOwner owner;

        public GitItem() {
        }

        public GitItem(Parcel in) {
            id = in.readInt();
            name = in.readString();
            full_name = in.readString();
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel out, int flags){
            out.writeInt(id);
            out.writeString(name);
            out.writeString(full_name);
        }

        public static final Parcelable.Creator<GitItem> CREATOR = new Parcelable.Creator<GitItem>(){

            @Override
            public GitItem createFromParcel(Parcel source) {
                return new GitItem(source);
            }

            @Override
            public GitItem[] newArray(int size) {
                return new GitItem[size];
            }
        };
    }

和 Git 所有者：

public class GitOwner implements Serializable, Parcelable {
    public String avatar_url;

    public GitOwner(Parcel in) {
        avatar_url = in.readString();
    }

    public GitOwner() {
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {

    }

    public static final Parcelable.Creator<GitOwner> CREATOR = new Parcelable.Creator<GitOwner>(){

        @Override
        public GitOwner createFromParcel(Parcel source) {
            return  new GitOwner(source);
        }

        @Override
        public GitOwner[] newArray(int size) {
            return new GitOwner[size];
        }
    };
}

然后在 MainActivity.java 我有一个 List<GitItem> data; 绑定到我的 RecyclerView.

基本上我想要实现的是在我更改 Activity 或简单地旋转设备时存储我的 List<GitItem> 的当前状态。不幸的是，即使我已经实现了 Parcelable（如其他帖子所建议的），我仍无法存储实例。

如有任何帮助，我们将不胜感激。

Answer 1

您尚未实现 Parcelable 函数的完整主体，即 GitOwner 和 GitItem class

中的 writeToParcel

在GitOwnerclass

@Override
public void writeToParcel(Parcel dest, int flags) {
     dest.writeString(avatar_url);
     // add this line
}

并在GitItem内部使用writeParcelable to write and readParcelable读取GitItem对象，否则它不会被持久化和恢复

    public GitItem(Parcel in) {
        id = in.readInt();
        name = in.readString();
        full_name = in.readString();
        owner = in.readParcelable(GitItem.class.getClassLoader());
        // Add line to read owner object
    }

    public void writeToParcel(Parcel out, int flags){
        out.writeInt(id);
        out.writeString(name);
        out.writeString(full_name);
        out.writeParcelable(owner , flags);           
        // Add line to write owner object
    }

使用 Parcelable 将 List<Object> 保存到实例状态

Save List<Object> to instance state with Parcelable

android

arraylist

android-savedstate

android-recyclerview