将 parcelable 添加到自定义对象的接口类答案

【问题标题】：adding parcelable to an interface class for custom objects将 parcelable 添加到自定义对象的接口类
【发布时间】：2015-02-08 10:32:51
【问题描述】：

我有一个自定义对象类，但它是通过接口实现的，我怎样才能将 parceable 合并到其中。我已经关注并搜索了parceable，但它仅适用于对象类。例如：How can I make my custom objects Parcelable?

我想将我的对象列表传递给 android 中的另一个活动。

代码：

public interface Projection {

  interface Job {
        @XBRead("./task")
        List<Task> getTasks();

        @XBRead("./id")
        String getid();

        @XBRead("./job_title")
        String getjob_title();

        @XBRead("./job_description")
        String getjob_description();

        @XBRead("./job_room")
        String getjob_room();

        @XBRead("./status")
        String getstatus();
    }

    interface Task {

        @XBRead("./task_id")
        String gettask_id();

        @XBRead("./task_title")
        String gettask_title();

        @XBRead("./task_description")
        String gettask_description();

        @XBRead("./task_status")
        String gettask_status();


    }

    @XBRead("/root/job")
    List<Job> getJobs();
}

【问题讨论】：

标签： android object android-intent android-activity parcelable

【解决方案1】：

您的自定义接口需要extend Parcelable。

实现您的自定义接口的类还需要实现Parcelable 接口，包括CREATOR。

然后您可以将实现您的自定义接口的对象添加到Intent，如下所示：

intent.putExtra("thing", thing);

或添加一个包含这些对象的ArrayList，如下所示：

ArrayList<Thing> things;
intent.putParcelableArrayListExtra("things", things);

在接收端，Activity 可以像这样从Intent 中提取对象：

Thing thing = intent.getParcelableExtra("thing");

或

ArrayList<Thing> things = intent.getParcelableArrayListExtra("things");

【讨论】：

【解决方案2】：

完整的代码看起来像

我的界面

public interface MyInterface extends Parcelable {

}

我的实现1

public class MyImplementation1 implements MyInterface, Parcelable {
    public final int var1;

    public MyImplementation1() {
        this.var1 = 1;
    }

    protected MyImplementation1(Parcel in) {
        var1 = in.readInt();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(var1);
    }

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

    public static final Creator<MyImplementation1> CREATOR = new Creator<MyImplementation1>() {
        @Override
        public MyImplementation1 createFromParcel(Parcel in) {
            return new MyImplementation1(in);
        }

        @Override
        public MyImplementation1[] newArray(int size) {
            return new MyImplementation1[size];
        }
    };
}

MyImplementation2

public class MyImplementation2 implements MyInterface, Parcelable {
    public final int var2;

    public MyImplementation2(int var2) {
        this.var2 = var2;
    }

    protected MyImplementation2(Parcel in) {
        var2 = in.readInt();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(var2);
    }

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

    public static final Creator<MyImplementation2> CREATOR = new Creator<MyImplementation2>() {
        @Override
        public MyImplementation2 createFromParcel(Parcel in) {
            return new MyImplementation2(in);
        }

        @Override
        public MyImplementation2[] newArray(int size) {
            return new MyImplementation2[size];
        }
    };
}

我的班级

public class MyClass implements Parcelable {

    private final MyInterface var1;
    private final List<MyInterface> var2;


    public MyClass(MyInterface var1, List<MyInterface> var2) {
        this.var1 = var1;
        this.var2 = var2;
    }

    protected MyClass(Parcel in) {
        var1 = in.readParcelable(MyInterface.class.getClassLoader());
        var2 = in.readArrayList(MyInterface.class.getClassLoader());
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeParcelable(var1, flags);
        dest.writeTypedList(var2);
    }

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

    public static final Creator<MyClass> CREATOR = new Creator<MyClass>() {
        @Override
        public MyClass createFromParcel(Parcel in) {
            return new MyClass(in);
        }

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

使用它

MainActivity1

public class MainActivity1 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_1);

        List<MyInterface> list = new ArrayList<>(2);
        list.add(new MyImplementation2(21));
        list.add(new MyImplementation2(22));

        MyClass myClass = new MyClass(new MyImplementation1(), list);

        Intent intent = new Intent(this, MainActivity2.class);
        Bundle b = new Bundle();
        b.putParcelable("key", myClass);
        intent.putExtras(b);
        startActivity(intent);
    }
}

MainActivity2

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_2);

        Bundle b = getIntent().getExtras();
        MyClass myClass = b.getParcelable("key");

    }
}

【讨论】：