java - 如何将 Parcelable 与 setter 和 getter 一起使用？

Question

我使用 Parcelable 实现，因为使用 putParcelableArrayListExtra 传递 ArrayList 更容易，但是 protected Song(Parcel in) and public void writeToParcel(Parcel dest, int flags) 的目的是什么？

我的可分割类

public class Song implements Parcelable {

    private long id = 0;
    private String data = "";
    private String title = "";
    private String artist = "";

    public Song(){
    }

    protected Song(Parcel in) {
          id = in.readLong();
          data = in.readString();
          title = in.readString();
          artist = in.readString();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeLong(id);
        dest.writeString(data);
        dest.writeString(title);
        dest.writeString(artist);
    }

    public void setId(long songId){ this.id = songId; }
    public long getId(){
        return id;
    }
    public void setData(String data) { this.data = data; }
    public String getData(){return data;}

    //Optional meta data

    public void setTitle(String title){ this.title = title; }
    public String getTitle() { return title; }

    public void setArtist(String artist){
        this.artist = artist;
    }
    public String getArtist() {
        return artist;
    }

对于它的用途，如果我没有向我的 Song() 构造函数传递任何参数，我是否还需要添加它，或者我可以将其留空吗？

protected Song(Parcel in) {
            id = in.readLong();
            data = in.readString();
            title = in.readString();
            artist = in.readString();
        }

 @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeLong(id);
            dest.writeString(data);
            dest.writeString(title);
            dest.writeString(artist);
        }

Answer 1

我们需要这个方法，因为它会覆盖方法，并且如果您不删除它并手动创建 setter 和 getter，那么 getter 和 setter 将自动工作

@Override
public void writeToParcel(Parcel dest, int flags) {
     dest.writeLong(id);
     dest.writeString(data);
     dest.writeString(title);
     dest.writeString(artist);
}