23

现在修改代码以反映公认的解决方案。

这现在用作如何将自定义 ArrayList 传递到 DialogFragment 的工作示例。

我正在使用 newInstance 上的 Bundle 将自定义对象的 ArrayList 传递给 DialogFragment。在 newInstance 中正确接收了 arraylist。对 putParcelable 的调用执行良好（没有错误），但是在 ArrayList 对象的 parcelable 代码中放置断点表明在设置或获取数据时未调用 parcel 方法。

我是否正确为 ArrayList 创建一个 LocalityList 类并使其可打包，或者 Locality 类本身应该是可打包的？

对话片段

/**
 * Create a new instance of ValidateUserEnteredLocationLocalitySelectorFragment, providing "localityList"
 * as an argument.
 */
public static ValidateUserEnteredLocationLocalitySelectorFragment newInstance(LocalityList localityList) {

    ValidateUserEnteredLocationLocalitySelectorFragment fragmentInstance = new ValidateUserEnteredLocationLocalitySelectorFragment();

    // Supply location input as an argument.
    Bundle bundle = new Bundle();
    bundle.putParcelable(KEY_LOCALITY_LIST, localityList);
    fragmentInstance.setArguments(bundle);

    return fragmentInstance;
}


/**
 * Retrieve the locality list from the bundle
 */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mLocalityList = getArguments().getParcelable(KEY_LOCALITY_LIST);
}


 @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.validate_user_entered_location, container, false);

    mLocalityListView = (ListView) view.findViewById(R.id.dialogLocalityListView);
    mAdapter = new SearchLocationLocalitiesListAdapter(getActivity(), mLocalityList);
    mLocalityListView.setAdapter(mAdapter);

    return view;
}

LocalityList 类

import java.util.ArrayList;

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

public class LocalityList extends ArrayList<Locality> implements Parcelable {

    private static final long serialVersionUID = 663585476779879096L;

    public LocalityList() {
    }

    @SuppressWarnings("unused")
    public LocalityList(Parcel in) {
        this();
        readFromParcel(in);
    }

    private void readFromParcel(Parcel in) {
        this.clear();

        // First we have to read the list size
        int size = in.readInt();

        for (int i = 0; i < size; i++) {
            Locality r = new Locality(in.readString(), in.readDouble(), in.readDouble());
            this.add(r);
        }
    }

    public int describeContents() {
        return 0;
    }

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

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

    public void writeToParcel(Parcel dest, int flags) {
        int size = this.size();

        // We have to write the list size, we need him recreating the list
        dest.writeInt(size);

        for (int i = 0; i < size; i++) {
            Locality r = this.get(i);

            dest.writeString(r.getDescription());
            dest.writeDouble(r.getLatitude());
            dest.writeDouble(r.getLongitude());
        }
    }
}

地方类

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


public class Locality implements Parcelable {

    private String mDescription;
    private double mLatitude;
    private double mLongitude;


    public Locality(String description, double latitude, double longitude) {
        super();
        this.mDescription = description;
        this.mLatitude = latitude;
        this.mLongitude = longitude;
    }

    public Locality(){
        super();
    }


    public String getDescription() {
        return mDescription;
    }

    public void setDescription(String description) {
        this.mDescription = description;
    }


    public double getLatitude() {
        return mLatitude;
    }

    public void setLatitude(double latitude) {
        this.mLatitude = latitude;
    }


    public double getLongitude() {
        return mLongitude;
    }

    public void setLongitude(double longitude) {
        this.mLongitude = longitude;
    }


    @SuppressWarnings("unused")
    public Locality(Parcel in) {
        this();
        readFromParcel(in);
    }

    private void readFromParcel(Parcel in) {
        this.mDescription = in.readString();
        this.mLatitude = in.readDouble();
        this.mLongitude = in.readDouble();
    }

    public int describeContents() {
        return 0;
    }

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

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


    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(mDescription);
        dest.writeDouble(mLatitude);
        dest.writeDouble(mLongitude);
    }
}
4

3 回答 3

9

我知道这个问题已经很老了，但是由于我最初是来这里寻找答案的，所以我想分享我的经验。

是的，你需要为你的Locality班级实现 Parcelable ，但就是这样。

如果您LocalityList只是 ArrayList 的包装器，那么您不需要它。

只需使用putParcelableArrayList方法。

ArrayList<Locality> localities = new ArrayList<Locality>;
...
Bundle bundle = new Bundle();
bundle.putParcelableArrayList(KEY_LOCALITY_LIST, localities);
fragmentInstance.setArguments(bundle);

return fragmentInstance;

并使用...检索它

localities = savedInstanceState.getParcelableArrayList(KEY_LOCALITY_LIST);

因此，除非您出于其他原因需要自定义 ArrayList，否则您可以避免做任何额外的工作，而只为您的 Locality 类实现 Parcelable。

于 2014-09-14T16:09:19.080 回答
7

是的，让Locality类本身Parcelable，不要忘记初始化 

ArrayList<Locality> mList= new ArrayList<Locality>();
于 2012-06-08T17:10:07.283 回答
-1

我通常使用的技巧是使用 Gson（来自谷歌）将列表解析为 Json。另一方面，我只是将 Json 中的字符串分回一个新列表。

从来没有注意到任何滞后。

于 2012-12-26T22:58:25.740 回答