我有一个叫做Order
的对象,我想在这些活动之间传递。目前我正在使用Parcelable
这样做。如何在使用Parcelable的活动之间传递具有其他对象列表的对象?
public class Order implements Parcelable {
private String email;
private Long timestamp;
private List<OrderItem> items;
public Order() { }
private Order(Parcel in) {
email = in.readString();
timestamp = in.readLong();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(email);
if (timestamp == null) {
dest.writeByte((byte) 0);
} else {
dest.writeByte((byte) 1);
dest.writeLong(timestamp);
}
dest.writeTypedList(items);
}
@Override
public int describeContents() {
return 0;
}
public static final Creator<Order> CREATOR = new Creator<Order>() {
@Override
public Order createFromParcel(Parcel in) {
return new Order(in);
}
@Override
public Order[] newArray(int size) {
return new Order[size];
}
};
// Getters
...
}
的items
字段是实现Parcelable
接口OrderItem
的List
对象。
public class OrderItem implements Parcelable {
private String orderedClothingId;
private int quantity;
public OrderItem() { }
public OrderItem(String orderedClothingId, int quantity) {
this.orderedClothingId = orderedClothingId;
this.quantity = quantity;
}
private OrderItem(Parcel in) {
orderedClothingId = in.readString();
quantity = in.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(orderedClothingId);
dest.writeInt(quantity);
}
@Override
public int describeContents() {
return 0;
}
public static final Creator<OrderItem> CREATOR = new Creator<OrderItem>() {
@Override
public OrderItem createFromParcel(Parcel in) {
return new OrderItem(in);
}
@Override
public OrderItem[] newArray(int size) {
return new OrderItem[size];
}
};
}
我们从一个活动传递称为order
的Order
对象到另一个我执行以下操作:
Intent intent = new Intent(mContext, ActivityTwo.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra(ORDER_DETAIL_INTENT_EXTRA_KEY, order);
mContext.startActivity(intent);
在ActivityTwo
我收集像这样的Order
对象:
Bundle data = getIntent().getExtras();
assert data != null;
mOrder = data.getParcelable(ORDER_DETAIL_INTENT_EXTRA_KEY);
然而,当我在中记录Order
对象中包含的items
字段时它是null
。如何在没有items
列表为空的活动之间传递原始非空Order
对象?
当我将它添加到我的类中时,没有方法'createTypedList'。 –
sorr,不记得创建foryou的方法,你可以使用readList和一个空列表(项目将保存值) –