Question

我在使用实现Parcelable的类读取字符串的ArrayList时遇到了麻烦。

我想将3个字符串列表发送到片段。我不明白的另一件事是我如何使用这个课程将这些数据实际发送到Fragment（我在其他地方读到你可以使用你自己的parcelable类来做这个，但我不知道＆＃39;我确切地知道如何）。

以下是相关代码，我会在我认为需要帮助的地方发表评论。

package com.tsjd.HotMeals;

import java.util.ArrayList;

import android.os.Parcel;
import android.os.Parcelable;

public class RecipeListViewParcer implements Parcelable{

    private ArrayList<String> titles;
    private ArrayList<String> descriptions;
    private ArrayList<String> images;

     private RecipeListViewParcer(Parcel in) {
            titles = in.readArrayList(String.class.getClassLoader()); //Need help here
            descriptions = in.readArrayList(String.class.getClassLoader()); //Need help here
            images = in.readArrayList(String.class.getClassLoader()); //Need help here
        }

    public int describeContents() {
        return 0;
    }

    public void writeToParcel(Parcel out, int flags) {
        out.writeList(titles); //Need help here
        out.writeList(descriptions); //Need help here
        out.writeList(images); //Need help here
    }

    public static final Parcelable.Creator<RecipeListViewParcer> CREATOR
            = new Parcelable.Creator<RecipeListViewParcer>() {
        public RecipeListViewParcer createFromParcel(Parcel in) {
            return new RecipeListViewParcer(in);
        }

        public RecipeListViewParcer[] newArray(int size) {
            return new RecipeListViewParcer[size];
        }
    };



}

Answer 1

我已经改变了你的类，添加了一个构造函数来初始化字段并重命名 RecipeListViewParcer到RecipeListViewParcel：）

package com.tsjd.HotMeals;

import java.util.ArrayList;

import android.os.Parcel;
import android.os.Parcelable;

public class RecipeListViewParcel implements Parcelable{

    private ArrayList<String> titles;
    private ArrayList<String> descriptions;
    private ArrayList<String> images;

    public RecipeListViewParcel(ArrayList<String> titles, ArrayList<String> descriptions, ArrayList<String> images) {
        this.titles = titles;
        this.descriptions = descriptions;
        this.images = images;
    }

    // Convenient constructor to read from Parcel
    private RecipeListViewParcel(Parcel in) {
        titles = in.readArrayList(String.class.getClassLoader()); //Need help here
        descriptions = in.readArrayList(String.class.getClassLoader()); //Need help here
        images = in.readArrayList(String.class.getClassLoader()); //Need help here
    }

    public int describeContents() {
        return 0;
    }

    // This method does actual job to write into the Parcel and called internally
    // You need to override this method for each child class
    @Override
    public void writeToParcel(Parcel out, int flags) {
        out.writeList(titles); //Need help here
        out.writeList(descriptions); //Need help here
        out.writeList(images); //Need help here
    }

    public static final Parcelable.Creator<RecipeListViewParcel> CREATOR
            = new Parcelable.Creator<RecipeListViewParcel>() {
        public RecipeListViewParcel createFromParcel(Parcel in) {
            return new RecipeListViewParcel(in);
        }

        public RecipeListViewParcel[] newArray(int size) {
            return new RecipeListViewParcel[size];
        }
    };

}

使用ArrayList <string>和扩展Parcelable </string>的类

1 个答案: