Question

我有一个自定义对象的arraylist，它扩展了Parecelable类，因此可以通过bundle或localbroadcast manager发送给Activity。

现在，当我尝试发送其他数组的arraylist，ArrayList<ArrayList<my_custom_object>>时，我的问题就出现了。我怎样才能做到这一点？

Answer 1

1.Custom parcelable class（替换为您的自定义parcelable类）：

import android.os.Parcel;
import android.os.Parcelable;

/**
 * Custom parcelable class
 */
public class MyParcelable implements Parcelable {

    public int data;

    public MyParcelable(int data) {
        this.data = data;
    }

    private MyParcelable(Parcel source) {
        // Reading custom data
        data = source.readInt();
    }

    public static final Parcelable.Creator<MyParcelable> CREATOR
            = new Parcelable.Creator<MyParcelable>() {

        @Override
        public MyParcelable createFromParcel(Parcel source) {
            return new MyParcelable(source);
        }

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

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        // Saving custom data
        dest.writeInt(data);
    }
}

2.实现扩展ArrayList的Parcelable类。

import android.os.Parcel;
import android.os.Parcelable;

import java.util.ArrayList;

/**
 * ArrayList of the custom parcelable object
 */
public class MyParcelableList extends ArrayList<MyParcelable> implements Parcelable {

    public MyParcelableList() {
    }
    private MyParcelableList(Parcel source) {
        for (Parcelable p : source.readParcelableArray(MyParcelable.class.getClassLoader()))
            add((MyParcelable) p);
    }

    public static final Parcelable.Creator<MyParcelableList> CREATOR
            = new Parcelable.Creator<MyParcelableList>() {

        @Override
        public MyParcelableList createFromParcel(Parcel source) {
            return new MyParcelableList(source);
        }

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

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeParcelableArray(toArray(new MyParcelable[size()]), flags);
    }
}

3.Passing Intent to TargetActivity。

// Preparing data ...
MyParcelableList list1 = new MyParcelableList();
list1.add(new MyParcelable(1));
MyParcelableList list2 = new MyParcelableList();
list2.add(new MyParcelable(2));
list2.add(new MyParcelable(3));
ArrayList<MyParcelableList> listOfList = new ArrayList<>();
listOfList.add(list1);
listOfList.add(list2);

// Send intent to your target activity
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("KEY_OF_EXTRA", listOfList);
context.startActivity(new Intent(context, TargetActivity.class).putExtras(bundle));

4.在TargetActivity上检索数据。

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

    // processing intent data
    if (getIntent()!=null) {
        Bundle bundle = getIntent().getExtras();
        if (bundle.containsKey("KEY_OF_EXTRA")) {
            ArrayList<MyParcelableList> listOfList = bundle.getParcelableArrayList("KEY_OF_EXTRA");
            if (listOfList != null)
                // Do something here ...
                for (MyParcelableList list : listOfList) {
                    for (MyParcelable p : list) {
                        Log.v("TargetActivity", "p.data=" + p.data);
                    }
                }
        }
    }
}

Answer 2

您可以尝试以下代码

ActivityA发送：

5.024

ActivityB get：

 ArrayList<ArrayList<CustomClass>>data = new ArrayList<ArrayList<CustomClass>>();
            ArrayList<CustomClass>d1 = new ArrayList<CustomClass>();
            CustomClass temp = new CustomClass("this is my object");
            d1.add(temp);
            data.add(d1);
            Intent intent = new Intent(JumpToMainActivity.ACTION);
            intent.putExtra("data",data);
            startActivity(intent);

CusstonClass.java：

Intent intent = getIntent();
    ArrayList<ArrayList<CustomClass>>data = (ArrayList<ArrayList<CustomClass>>) intent.getSerializableExtra("data");
    ArrayList<CustomClass>d1 = data.get(0);
    System.out.println("received:" + d1.get(0).result);

希望能帮到你

将其他数组的ArrayList传递给活动

2 个答案: