如何传递包含对象列表的可包装对象？

我在下面创建了一个 Parcelable对象，我的对象包含产品的 List。在构造函数中，如何为 List重新创建 Parcelable？

我已经检查了所有的方法可从包裹和所有可用的是 readArrayList(ClassLoader)。我不确定这是不是最好的方法，我真的很感激你的建议。

public class Outfits implements Parcelable {


private String url;
private String name;
private List<Product> products;


public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<Product> getProducts() {
return products;
}
public void setProducts(List<Product> products) {
this.products = products;
}


public void writeToParcel(Parcel dest, int flags) {
Log.v("", "writeToParcel..." + flags);
dest.writeString(url);
dest.writeString(name);
dest.writeList(products);
}




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


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


@Override
public int describeContents() {
return 0;
}


/*** Here how do I populate my List of Products ***/
private Outfits(Parcel in) {
url = in.readString();
name = in.readString();
products = in.read ???????;
}
}
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最佳答案

If class Product is compatible with parcelable protocol, following should work according to documentation.

products = new ArrayList<Product>();
in.readList(products, Product.class.getClassLoader());
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This should work:

in.readTypedList(products, Product.CREATOR);
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First, your Product object must implements Parcelable.

And then, use dest.writeTypedList(products) in writeToParcel() method.

Finally, use following code to parse the list:

products = new ArrayList<Product>();
in.readTypedList(products, Product.CREATOR);

For more infomation, please reference the Official Document:

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implement Parcelable on the Product class as well and then

in.readList(this.list, Product.class.getClassLoader());

if any of the above solutions didn't work.

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The other way is to use readValue&writeValue. 

protected Product (Parcel in) {
...
in.readValue(this.getClass().getClassLoader());
}


@Override
public void writeToParcel(Parcel parcel, int i) {
...
parcel.writeValue(**list**);
}

Items of the list should implement Parcelable

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In my personal experience, http://www.parcelabler.com/ is an amazing site for this. You just create your class, and copy paste it into the website, and it generates a Parcelable version of your class.

I tested it with a class named "Theme" that contained the following variables:

private String name;
private int image;
private List<Card> cards;

The writeToParcel function becomes:

@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(name);
dest.writeInt(image);
if (cards == null) {
dest.writeByte((byte) (0x00));
} else {
dest.writeByte((byte) (0x01));
dest.writeList(cards);
}
}

generated constructor:

protected Theme(Parcel in) {
name = in.readString();
image = in.readInt();
if (in.readByte() == 0x01) {
cards = new ArrayList<Card>();
in.readList(cards, Card.class.getClassLoader());
} else {
cards = null;
}
}

EDIT: make sure that the Card object is also Parcelable!

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Here you go...

Make sure "Products.java" should be extended with Parcelable

Step 1:

 private List<Products> products;

Step 2:

private Outfits(Parcel in) {
products = in.createTypedArrayList(Products.CREATOR);
}

Step 3:

@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeTypedList(products);
}
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Assuming the Product is implementing Parcelable, you can use this for writing:

dest.writeValue(products);

and this for reading:

products = (List<Product>) in.readValue(Product.class.getClassLoader());
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Product must be implements Parcelable 

  Product class implements  Parcelable {
......
}

Then write you object contains list like

public class Outfits implements Parcelable {


private String url;
private String name;
private List<Product> products;


public Outfits (Parcel pi) {


bookName = p.readString();
bookId = p.readInt();
isColor = p.readInt() == 1;


//use this well be get err
//products=p.readArrayList(Thread.currentThread().getContextClassLoader());


//Pass list use this
products= in.createTypedArrayList(Product.CREATOR);


}


...get and set...


public void writeToParcel(Parcel dest, int flags) {




dest.writeString(url);
dest.writeString(name);


//use this will no working
//dest.writeList(products);


//Parcelable list
out.writeTypedList(products);


}


}

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