Android GetParcelableExtra对象始终返回null

Question

因此，我试图将一个对象从一个活动发送到另一个活动，但接收器端上的对象始终为null。该对象完全填充在发件人侧，因此我几乎可以肯定它必须对阅读对象做一些事情。

这是包裹的对象：

import android.graphics.Bitmap;
import android.os.Parcel;
import android.os.Parcelable;
public class Picture implements Parcelable {
    public String pictureID, title, year, price, author;
    public Bitmap picture;
    public Picture(){
    }
    public int describeContents() {
        return 0;
    }
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(pictureID);
        dest.writeString(title);
        dest.writeString(year);
        dest.writeString(price);
        dest.writeString(author);
        dest.writeParcelable(picture, flags);
    }
    protected Picture(Parcel in) {
        pictureID = in.readString();
        title = in.readString();
        year = in.readString();
        price = in.readString();
        author = in.readString();
        picture = in.readParcelable(Bitmap.class.getClassLoader());
    }
    public static final Parcelable.Creator<Picture> CREATOR = new Parcelable.Creator<Picture>() {
        public Picture createFromParcel(Parcel source) {
            return new Picture(source);
        }
        public Picture[] newArray(int size) {
            return new Picture[size];
        }
    };
}

发送者活动：

Picture firstPic = new Picture();
firstPic.pictureID = "1";
firstPic.title = "Mona Lisa";
firstPic.author = "Leonardo Da Vinci";
firstPic.price = "99999000";
firstPic.year = "2250";
firstPic.picture = BitmapFactory.decodeResource(getApplication().getResources(),R.drawable.monalisa);
Intent i = new Intent(getApplicationContext(),MainScreen.class);
i.putExtra("first",firstPic);
startActivity(i);
finish();

接收者活动：

Picture currentPicture = new Picture();
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Intent intent = getIntent();
    currentPicture = intent.getParcelableExtra("first");
}

编辑：我已经检查了有关包裹的所有其他主题，我也遵循了本教程，我找不到错误的区别。

编辑2 ：问题已解决。从一开始，一切都很好，但是由于某种原因，我在用数据和putextra填充对象之间放了更多代码，所以基本上我是在发送一个空的对象 _（ツ）_/¯

Answer 1

首先避免通过位图，它们可能太大，并将字符串"first"提取到ReceiverActivity类的常数：

public class ReceiverActivity extends ... {
    public static final String EXTRA_FIRST = "first";
    ...
} 

so：

i.putExtra(ReceiverActivity.EXTRA_FIRST,firstPic);

和

currentPicture = intent.getParcelableExtra(ReceiverActivity.EXTRA_FIRST);

我已经发生了这种奇怪的事情，我以这种方式解决了它。