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Parcelable を使用してあるアクティビティから別のアクティビティにオブジェクトを転送していますが、別のアクティビティでそのオブジェクトを取得すると null が表示されます。助言がありますか？

コードは次のとおりです。

public class TPackage implements Parcelable {

// private static final long serialVersionUID = 1L;
private int cost;
private String name;
private int totalChannels;
private HashMap<String, Channel> channelList;

public int getCost() {
    return cost;
}

public void setCost(int cost) {
    this.cost = cost;
}

public int getTotal_channels() {
    return totalChannels;
}

public void setTotal_channels(int total_channels) {
    this.totalChannels = total_channels;
}

public HashMap<String, Channel> getList() {
    return channelList;
}

public void setList(HashMap<String, Channel> list) {
    this.channelList = list;
}

public void put(String name, Channel c) {
    channelList.put(name, c);
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {

}

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

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

}

4

2 に答える 2

2

これは、parcel andorid を使用してオブジェクトを転送する正しい方法です

public class TPackage implements Parcelable {

// private static final long serialVersionUID = 1L;
private int cost;
private String name;
private int totalChannels;
private HashMap<String, Channel> channelList;

public TPackage(int cost, String name, int totalChannels,
        HashMap<String, Channel> channelList){
    this.cost = cost;
    this.name = name;
    this.totalChannels = totalChannels;
    this.channelList = channelList;
}


public TPackage(Parcel in){
    //same order as that in writeToParcel()
    cost = in.readInt();
    name = in.readString();
    totalChannels = in.readInt();
    Bundle bundle = in.readBundle();
    channelList = (HashMap<String, Channel>) bundle.getSerializable("channelList");
}

public int getCost() {
    return cost;
}

public void setCost(int cost) {
    this.cost = cost;
}

public int getTotal_channels() {
    return totalChannels;
}

public void setTotal_channels(int total_channels) {
    this.totalChannels = total_channels;
}

public HashMap<String, Channel> getList() {
    return channelList;
}

public void setList(HashMap<String, Channel> list) {
    this.channelList = list;
}

public void put(String name, Channel c) {
    channelList.put(name, c);
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {
    dest.writeInt(cost);
    dest.writeString(name);
    dest.writeInt(totalChannels);
    //easiest way to transfer HashMap via parcel
    Bundle bundle = new Bundle();
    bundle.putSerializable("channelList", channelList);
    dest.writeBundle(bundle);
}

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

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

}

[編集済み] これは送信者のアクティビティです

public class MyActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TPackage tPackage = new TPackage(10, "hello", 123, new HashMap<String, Channel>());
        Intent intent = new Intent(this, NActivity.class);
        intent.putExtra("parcel", tPackage);
        startActivity(intent);
    }
}

これがレシーバー アクティビティです。

public class NActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Intent intent = getIntent();
        TPackage tPackage = intent.getParcelableExtra("parcel");
        HashMap<String, Channel> hashMap = tPackage.getList();
        Log.d("MyTag", "cost : " + tPackage.getCost() + " name: " + tPackage.getName()
                + " total channels: " + tPackage.getTotal_channels() + " list count: " + hashMap.size());
    }
}

Logcat 出力

09-13 21:57:20.578: DEBUG/MyTag(1478): cost : 10 name: hello total channels: 123 list count: 0
于 2012-09-13T13:38:43.323 に答える
0

createFromParcel と writeToParcel に実際に何かを入れる必要がある場合があります (オブジェクトのコンテンツなど)。

于 2012-09-13T13:24:59.207 に答える