Question

我上了3节课。系列，季节和剧集。 Series类有一个Season对象列表，Season类有一个Episode对象列表。

我想将Series对象发送到这样的其他活动。

Intent intent = new Intent(context, OtherActivity.class);
intent.putExtra("series", (Parcelable)seriesObject);

但是我得到一个NullPointerException。

以下是实现Parcelable的类。

系列课程：

public class Series implements Parcelable {

private int seasonCount;
public ArrayList<Season>seasons;
private String seriesName;
private int lastSeenSeason = 0;
private int lastSeenEpisode = 0;

public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {
    dest.writeInt(seasonCount);
    dest.writeTypedList(seasons);
    dest.writeString(seriesName);
    dest.writeInt(lastSeenSeason);
    dest.writeInt(lastSeenEpisode);
}

private Series(Parcel in){
    seasonCount = in.readInt();
    in.readTypedList(seasons, Season.CREATOR);
    seriesName = in.readString();
    lastSeenSeason = in.readInt();
    lastSeenEpisode = in.readInt();
}

public static final Parcelable.Creator<Series> CREATOR = new Parcelable.Creator<Series>() {
    public Series createFromParcel(Parcel in) {
        return new Series(in);
    }
    public Series[] newArray(int size) {
        return new Series[size];
    }
};

季节课：

public class Season implements Parcelable{

private int seasonNo;
private int episodeCount;
public ArrayList<Episode> episodes;


public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {
    dest.writeInt(seasonNo);
    dest.writeInt(episodeCount);
    dest.writeTypedList(episodes);
}

private Season(Parcel in){
    this.seasonNo = in.readInt();
    episodeCount = in.readInt();
    in.readTypedList(episodes, Episode.CREATOR);
}

public static final Parcelable.Creator<Season> CREATOR = new Parcelable.Creator<Season>() {
    public Season createFromParcel(Parcel in) {
        return new Season(in);
    }
    public Season[] newArray(int size) {
        return new Season[size];
    }
};

和Episode类：

public class Episode implements Parcelable{

private int episodeNo;
private boolean episodeSeen;


public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeInt(episodeNo);
    dest.writeByte((byte) (episodeSeen ? 1 : 0));
}

private Episode(Parcel in){
    episodeNo = in.readInt();
    episodeSeen = in.readByte() != 0;
}


public static final Parcelable.Creator<Episode> CREATOR = new Parcelable.Creator<Episode>() {
    public Episode createFromParcel(Parcel in) {
        return new Episode(in);
    }
    public Episode[] newArray(int size) {
        return new Episode[size];
    }
};

Answer 1

您应该初始化数组：

public ArrayList<Episode> episodes = new ArrayList<Episode>();
public ArrayList<Season> seasons = new ArrayList<Season>();

否则readTypedList将失败。

将Parcelable对象发送到另一个活动

1 个答案: