Android 使用包含另一个 hashmap 的 hashmap 实现 Parcelable 对象

Question

这是 Android 实现 Parcelable 对象的扩展，它有 hashmap 但我的有点不同。

我有这些课程

public class EventDetails implements Parcelable {
    Private String id;
    Private String eventName;
    Private Long eventUnixTime;
    Private HashMap <String, User> pickedUser = null;
}

和

public class User implements Parcelable {
    private String email;
    private String userName;
    private String userPicture;
    private Boolean hasLoggedInWithPassword;
    private HashMap<String, Object> dateJoined = null;

    public User() {

    }

    public User(String email, String userName, String userPicture, Boolean hasLoggedInWithPassword, HashMap<String, Object> dateJoined) {
        this.email = email;
        this.userName = userName;
        this.userPicture = userPicture;
        this.hasLoggedInWithPassword = hasLoggedInWithPassword;
        this.dateJoined = dateJoined;
    }

    protected User(Parcel in) {
        email = in.readString();
        userName = in.readString();
        userPicture = in.readString();

        int size = in.readInt();
        for (int i = 0; i < size; i++) {
            String key = in.readString();
            Object value = in.readString();
            dateJoined.put(key, value);
        }
    }

    public static final Creator<User> CREATOR = new Creator<User>() {
        @Override
        public User createFromParcel(Parcel in) {
            return new User(in);
        }

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

    public String getEmail() {
        return email;
    }

    public String getUserName() {
        return userName;
    }

    public String getUserPicture() {
        return userPicture;
    }

    public Boolean getHasLoggedInWithPassword() {
        return hasLoggedInWithPassword;
    }

    public HashMap<String, Object> getDateJoined() {
        return dateJoined;
    }

    @Override
    public int describeContents() {
        Log.i("describeUser", "describe content from User.java");

        return 0;
    }

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

        Log.i("write to Parcel", "write to Parcel from User.java");
        dest.writeString(email);
        dest.writeString(userName);
        dest.writeString(userPicture);
        dest.writeInt(hasLoggedInWithPassword ? 1:0);

        dest.writeInt(dateJoined.size());
        for (HashMap.Entry<String, Object> entry : dateJoined.entrySet()) {
            dest.writeString(entry.getKey());
            dest.writeString(String.valueOf(entry.getValue()));
        }
    }
}

我被困在 EventDetails 类中的这些方法中：

protected EventDetails(Parcel in) {
    id = in.readString();
    eventName = in.readString();
    eventUnixTime = in.readLong();

    final int size = in.readInt();
    for (int i = 0; i < size; i++) {
        String key = in.readString();
        User user = in.readHashMap(userMap);
        pickedFriendsHashMap.put(key, user);
    }
}

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

        dest.writeInt(pickedFriendsHashMap.size());

        for (HashMap.Entry<String, User> entry :    pickedFriendsHashMap.entrySet()) {
            dest.writeString(entry.getKey());

        dest.writeInt(listLength);

        for (User user: userList) {
            dest.writeParcelable(user, 0);
        }
    }

    dest.writeString(id);
    dest.writeString(eventName);
    dest.writeLong(eventUnixTime);
}

请告知我如何正确地将这些课程打包并打包发送。

谢谢。

-R

Answer 1

Android studio 已经提供插件

(Android Parcelable code generator)

自动生成

Parcelable

方法。

为了使用上面的插件，我用

Parcelable

自动生成的方法创建了下面的类

public class EventDetails implements Parcelable {

    private String id;
    private String eventName;
    private Long eventUnixTime;
    private HashMap<String, User> pickedUser;


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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.id);
        dest.writeString(this.eventName);
        dest.writeValue(this.eventUnixTime);
        dest.writeSerializable(this.pickedUser);
    }

    public EventDetails() {
    }

    protected EventDetails(Parcel in) {
        this.id = in.readString();
        this.eventName = in.readString();
        this.eventUnixTime = (Long) in.readValue(Long.class.getClassLoader());
        this.pickedUser = (HashMap<String, User>) in.readSerializable();
    }

    public static final Creator<EventDetails> CREATOR = new Creator<EventDetails>() {
        @Override
        public EventDetails createFromParcel(Parcel source) {
            return new EventDetails(source);
        }

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

public class User implements Parcelable {
    private String email;
    private String userName;
    private String userPicture;
    private Boolean hasLoggedInWithPassword;
    private HashMap<String, Object> dateJoined = null;

    public User(String email, String userName, String userPicture, Boolean hasLoggedInWithPassword, HashMap<String, Object> dateJoined) {
        this.email = email;
        this.userName = userName;
        this.userPicture = userPicture;
        this.hasLoggedInWithPassword = hasLoggedInWithPassword;
        this.dateJoined = dateJoined;
    }


    public String getEmail() {
        return email;
    }

    public String getUserName() {
        return userName;
    }

    public String getUserPicture() {
        return userPicture;
    }

    public Boolean getHasLoggedInWithPassword() {
        return hasLoggedInWithPassword;
    }

    public HashMap<String, Object> getDateJoined() {
        return dateJoined;
    }


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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.email);
        dest.writeString(this.userName);
        dest.writeString(this.userPicture);
        dest.writeValue(this.hasLoggedInWithPassword);
        dest.writeSerializable(this.dateJoined);
    }

    protected User(Parcel in) {
        this.email = in.readString();
        this.userName = in.readString();
        this.userPicture = in.readString();
        this.hasLoggedInWithPassword = (Boolean) in.readValue(Boolean.class.getClassLoader());
        this.dateJoined = (HashMap<String, Object>) in.readSerializable();
    }

    public static final Creator<User> CREATOR = new Creator<User>() {
        @Override
        public User createFromParcel(Parcel source) {
            return new User(source);
        }

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