安卓类Parcelable用的ArrayList [英] Android Class Parcelable with ArrayList

问题描述

我有一个Android项目中，我有一个类。在这个类是一个的ArrayList＆LT;选择＆GT; 。我会得到一些XML，解析出来，然后使物体出来吧，我会被传递到另一个活动。我选择Parcelable这一点。

I have an android project where I have a class. In that class is an ArrayList<Choices>. I will be getting some XML, parsing it out, then making objects out of it which I will be passing to another activity. I'm choosing Parcelable for this.

时Parcelable一个好的选择吗？我是否在做正确的一切吗？我不Parcelable真正熟悉。我的ArrayList的是，我这个类中做了另一个类。会否对象的ArrayList的正确传递给包裹它不扩展Parcelable之类的东西？

Is Parcelable a good choice? Am I doing everything correctly? I'm not familiar really with Parcelable. My ArrayList is of another class that I made within this class. Will it properly pass that ArrayList of objects to the Parcel with it not extending Parcelable and stuff?

import java.util.ArrayList;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.os.ParcelableCompat;

public class Question implements Parcelable{


String id;
String text;
String image;
ArrayList<Choices> CHOICES;


public Question(String id, String text, String image) {
    super();
    this.id = id;
    this.text = text;
    this.image = image;
}

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getText() {
    return text;
}

public void setText(String text) {
    this.text = text;
}

public String getImage() {
    return image;
}

public void setImage(String image) {
    this.image = image;
}

@Override
public String toString() {
    return "Question [id=" + id + ", text=" + text + ", image=" + image
            + "]";
}




// Answer Choices class
class Choices {

    boolean isCorrect;
    String choice;

    public Choices(boolean isCorrect, String choice) {
        this.isCorrect = isCorrect;
        this.choice = choice;
    }

    public String getChoice() {
        return choice;
    }

    public boolean getIsCorrect() {
        return isCorrect;
    }

    @Override
    public String toString() {
        return "Choices [isCorrect=" + isCorrect + ", choice=" + choice
                + "]";
    }

}


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

    @Override
    public Question createFromParcel(Parcel in) {
        return new Question(in);
    }

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

};

@Override
public int describeContents() {
    // TODO Auto-generated method stub
    return 0;
}

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

    dest.writeString(id);
    dest.writeString(text);
    dest.writeString(image);
    dest.writeList(CHOICES);

}

private Question(Parcel in) {
    this.id = in.readString();
    this.text = in.readString();
    this.image = in.readString();
    this.CHOICES = in.readArrayList(Choices.class.getClassLoader());
}

}

感谢您的帮助！

Thanks for any help!

推荐答案

如果你需要传递一个的ArrayList 活动之间，那么我会与执行<$ C去$ C> Parcelable 此外，因为没有其他方式，我猜。 不过，我不认为你会需要这么多的getter和setter。这是你的问题类，它实现了 Parcelable ：

If you need to pass an ArrayList between activities, then I'd go with implementing Parcelable also, as there is no other way around I guess. However I don't think you will need that much of getters and setters. Here is your Question class which implements Parcelable:

public class Question implements Parcelable {
    public String id;
    public String text;
    public String image;
    public ArrayList<Choice> choices;


    /**
     * Constructs a Question from values
     */
    public Question (String id, String text, String image, ArrayList<Choice> choices) {
        this.id = id;
        this.text = text;
        this.image = image;
        this.choices = choices;
    }

    /**
     * Constructs a Question from a Parcel
     * @param parcel Source Parcel
     */
    public Question (Parcel parcel) {
        this.id = parcel.readString();
        this.text = parcel.readString();
        this.image = parcel.readString();
        this.choices = parcel.readArrayList(null);
    }

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

    // Required method to write to Parcel
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(id);
        dest.writeString(text);
        dest.writeString(image);
        dest.writeList(choices);
    }

    // Method to recreate a Question from a Parcel
    public static Creator<Question> CREATOR = new Creator<Question>() {

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

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

    };
}

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