Question

我正在尝试使以下类可以使用。通常，我通过使用parcelabler网站来做到这一点。但该网站似乎存在ArrayList＆gt;的问题。部分。有人知道如何正确地做到这一点吗？提前谢谢！

package com.example.stoos.data;

import java.util.ArrayList;

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

public class DataModelDiagrammDaten implements Parcelable {
ArrayList<String> Antworten = new ArrayList<String>();
ArrayList<ArrayList<Integer>> AntwortIDs = new ArrayList<ArrayList<Integer>>();

public ArrayList<String> getAntworten() {
    return Antworten;
}

public ArrayList<ArrayList<Integer>> getAntwortIDs() {
    return AntwortIDs;
}

public void setAntworten(ArrayList<String> antworten) {
    Antworten = antworten;
}

public void setAntwortIDs(ArrayList<ArrayList<Integer>> antwortIDs) {
    AntwortIDs = antwortIDs;
}

public DataModelDiagrammDaten(ArrayList<String> antworten,
        ArrayList<ArrayList<Integer>> antwortIDs) {
    super();
    Antworten = antworten;
    AntwortIDs = antwortIDs;
}



protected DataModelDiagrammDaten(Parcel in) {
    if (in.readByte() == 0x01) {
        Antworten = new ArrayList<String>();
        in.readList(Antworten, String.class.getClassLoader());
    } else {
        Antworten = null;
    }
}

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

@Override
public void writeToParcel(Parcel dest, int flags) {
    if (Antworten == null) {
        dest.writeByte((byte) (0x00));
    } else {
        dest.writeByte((byte) (0x01));
        dest.writeList(Antworten);
    }
}

@SuppressWarnings("unused")
public static final Parcelable.Creator<DataModelDiagrammDaten> CREATOR = new Parcelable.Creator<DataModelDiagrammDaten>() {
    @Override
    public DataModelDiagrammDaten createFromParcel(Parcel in) {
        return new DataModelDiagrammDaten(in);
    }

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

Answer 1

我认为这有点晚了，但希望它对其他人有用。我试着像这样写一个二维数组到Parcel：

public class Avatar implements Parcelable {

ArrayList<Integer> arrayList;
ArrayList<ArrayList<Integer>> arrayLists;

public Avatar() {
    arrayLists = new ArrayList<>();
    for (int i = 0; i < 10; i++) {
        ArrayList<Integer> temp = new ArrayList<>();
        for (int j = 0; j < 10; j++) {
            temp.add(j);
        }
        arrayLists.add(temp);
    }

    arrayList = new ArrayList<>();
    for (int i = 100; i < 104; i++) {
        arrayList.add(i);
    }
}

protected Avatar(Parcel in) {
    arrayList = new ArrayList<>();
    in.readList(arrayList, Integer.class.getClassLoader());
    arrayLists = new ArrayList<>();
    in.readList(arrayLists, ArrayList.class.getClassLoader());
}

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

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

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

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeList(arrayList);
    dest.writeList(arrayLists);
}

@Override
public String toString() {
    StringBuilder stringBuilder = new StringBuilder();
    for (int i = 0; i < arrayList.size(); i++) {
        stringBuilder.append(arrayList.get(i) + " ");
    }
    for (int i = 0; i < arrayLists.size(); i++) {
        for (int j = 0; j < arrayLists.get(i).size(); j++) {
            stringBuilder.append(arrayLists.get(i).get(j) + " ");
        }
    }
    return stringBuilder.toString();
}
}

将课程发送到另一个活动：

   avatar = new Avatar();
   Intent intent = new Intent();
   intent.setClass(ParcelActivity.this, Parcel2Activity.class);
   intent.putExtra("avatar", avatar);
   startActivity(intent);

接收另一项活动：

textView.setText(getIntent().getParcelableExtra("avatar") + "");

它正常工作： test

应该注意的是，Parcel中字段对象的写入和读取必须是相同的顺序。

Answer 2

修改：

尝试将第二个ArrayList放在另一个类中：

public class IdsObject implements Parcelable { ArrayList<Integer> ids; public IdsObject(ArrayList<Integer> ids) { this.ids = ids; } protected IdsObject(Parcel in) { if (in.readByte() == 0x01) { ids = new ArrayList<Integer>(); in.readList(ids, Integer.class.getClassLoader()); } else { ids = null; } } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel dest, int flags) { if (ids == null) { dest.writeByte((byte) (0x00)); } else { dest.writeByte((byte) (0x01)); dest.writeList(ids); } } @SuppressWarnings("unused") public static final Parcelable.Creator<IdsObject> CREATOR = new Parcelable.Creator<IdsObject>() { @Override public IdsObject createFromParcel(Parcel in) { return new IdsObject(in); } @Override public IdsObject[] newArray(int size) { return new IdsObject[size]; } }; }

然后，在你的课堂上使用这个课程：

public class DataModelDiagrammDaten implements Parcelable, Parcelable { ArrayList<String> Antworten = new ArrayList<String>(); ArrayList<IdsObject> AntwortIDs = new ArrayList<IdsObject>(); protected DataModelDiagrammDaten(Parcel in) { if (in.readByte() == 0x01) { Antworten = new ArrayList<String>(); in.readList(Antworten, String.class.getClassLoader()); } else { Antworten = null; } if (in.readByte() == 0x01) { AntwortIDs = new ArrayList<IdsObject>(); in.readList(AntwortIDs, IdsObject.class.getClassLoader()); } else { AntwortIDs = null; } } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel dest, int flags) { if (Antworten == null) { dest.writeByte((byte) (0x00)); } else { dest.writeByte((byte) (0x01)); dest.writeList(Antworten); } if (AntwortIDs == null) { dest.writeByte((byte) (0x00)); } else { dest.writeByte((byte) (0x01)); dest.writeList(AntwortIDs); } } @SuppressWarnings("unused") public static final Parcelable.Creator<DataModelDiagrammDaten> CREATOR = new Parcelable.Creator<DataModelDiagrammDaten>() { @Override public DataModelDiagrammDaten createFromParcel(Parcel in) { return new DataModelDiagrammDaten(in); } @Override public DataModelDiagrammDaten[] newArray(int size) { return new DataModelDiagrammDaten[size]; } }; }

Answer 3

好的，我解决了。如果其他人遇到同样的问题，这是解决方案：您可以先使用可与网站配对的普通ArrayList（而不是ArrayList＆gt;）来创建您的类。然后使用以下代码片段将其写入构造函数，并在该位置使用Parcel参数，如果是ArrayList的话。现在将ArrayList更改回ArrayList＆gt;它应该工作。

if (in.readByte() == 0x01) {
        IDs = new ArrayList<ArrayList<Integer>>();
        Type collectionType =  new TypeToken<ArrayList<Integer>>(){}.getType();  
        in.readList(IDs, collectionType.getClass().getClassLoader());
    } else {
        IDs = null;
    }

Make ArrayList <arraylist <integer>＆gt; parcelable </数组列表<整数>

3 个答案: