如何使用parcelable将对象从一项活动转移到另一项活动？

Question

我使用parcelable将一个对象从一个活动转移到另一个活动，但它显示为空 在另一活动中检索该对象。 有什么建议吗？

下面的代码：

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]; 
    } 
}; 

}

Answer 1

您可能需要居然把东西在createFromParcel和writeToParcel（如对象的内容）

Answer 2

这是正确的方式使用包裹转移您的物品andorid

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]; 
    } 
}; 

} 

[编辑] 这是发送者的活动

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); 
    } 
} 

这是接收器的工作

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的输出

09-13 21:57:20.578: DEBUG/MyTag(1478): cost : 10 name: hello total channels: 123 list count: 0