Parcel序列化

下面的这段话摘自Parcelable的文档：

Interface for classes whose instances can be written to and restored from a Parcel. Classes implementing the Parcelable interface must also have a static field called CREATOR, which is an object implementing the Parcelable.Creator interface.

从典型来看，实现该接口需要实现2个接口，writeToParcel(Parcel dest, int flags)和describeContents()。除此之外，还必须新建一个含有 Creator的属性。典型的用法如下：

public class User implements Parcelable{

    private String name;
    private String email;
    private int age;


    public User(String name, String email, int age) {
        this.name = name;
        this.email = email;
        this.age = age;
    }


    public String getName() {
        return name;
    }


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


    public String getEmail() {
        return email;
    }


    public void setEmail(String email) {
        this.email = email;
    }


    public int getAge() {
        return age;
    }


    public void setAge(int age) {
        this.age = age;
    }


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


    @Override
    public void writeToParcel(Parcel dest, int flags) {
        Bundle bundle = new Bundle();
        bundle.putString("name", getName());
        bundle.putString("email", getEmail());
        bundle.putInt("age", getAge());
        dest.writeBundle(bundle);
    }


    public static final Creator<User> CREATOR = new Creator<User>() {
        @Override
        public User createFromParcel(Parcel source) {
            Bundle bundle = source.readBundle();
            return new User (bundle.getString("name"), bundle.getString("email"), bundle.getInt("age"));
        }


        @Override
        public User[] newArray(int size) {
            return new User[size];
        }
    };


    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", email='" + email + '\'' +
                ", age=" + age +
                '}';
    }

}

如果碰到readBundle: bad magic number的错误，请检查是否多次使用source.readBundle()来读取同一个内容，第二次调用将会返回异常。