传球意图之间Parcelable对象 [英] Passing Parcelable Object between Intents

问题描述

我有一个问题，我路过了事件之间创造了一个对象。我用的网站 http://www.parcelabler.com/ 创建$ C $的parcelable元素C。 Object类下面显示：（Item类是包含字符串和双打另一个简单的对象，并也取得了parcelable）

I am having an issue passing an object I have created in between events. I used the website http://www.parcelabler.com/ to create the parcelable element of the code. The object class is show below: (The Item class is another simple object containing Strings and doubles and has also been made parcelable)

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

import java.util.ArrayList;

public class Diner implements Parcelable {

    private String name;
    private ArrayList<Item> itemList = new ArrayList<Item>();

    public Diner(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void addItem(Item foodItem) {
        itemList.add(foodItem);
        foodItem.incrementBuyerCount();
    }

    public double getPrice() {
        double total = 0;
        for(Item item : itemList) {
            total += item.getPrice() / item.getBuyerCount();
        }
        return total;
    }


    protected Diner(Parcel in) {
        name = in.readString();
        if (in.readByte() == 0x01) {
            itemList = new ArrayList<Item>();
            in.readList(itemList, Item.class.getClassLoader());
        } else {
            itemList = null;
        }
    }

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

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

    @SuppressWarnings("unused")
    public static final Parcelable.Creator<Diner> CREATOR = new Parcelable.Creator<Diner>() {
        @Override
        public Diner createFromParcel(Parcel in) {
            return new Diner(in);
        }

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

在我的主要活动中，我有一个打开添加晚餐的活动，当按钮被pressed并等待结果。

In my main activity, I have a button which opens an 'Add Diner' activity, when a button is pressed and waits for a result.

private final int SET_REQUEST = 1;

addDinerButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(getApplicationContext(), AddDinerActivity.class);
        startActivityForResult(intent, SET_REQUEST);
    }
});

在添加晚餐活动开启后，用户将在一个晚餐名称的EditText一个字符串，它使用了创建一个新的晚餐对象，并返回到主活动时确定按钮是pressed。

The Add Diner activity is opened, the user enters a String in a Diner Name EditText which is used the create a new Diner object and returns to the main activity when an OK button is pressed.

okButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = getIntent();
        Diner newDiner = new Diner(dinerNameEditText.getText().toString());
        intent.putExtra("newDiner", newDiner);
        setResult(RESULT_OK, intent);
        finish();
    }
});

最后晚餐对象接收并添加到阵列中的主要活动：

Finally the Diner object is received and added to an array in the main activity:

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(resultCode == RESULT_OK) {
        if(requestCode == SET_REQUEST) {
            Diner newDiner = getIntent().getParcelableExtra("newDiner");
            dinerList.add(newDiner);
        }
    }
}

不幸的是，当我尝试保存晚餐对象，并把它传递给主要活动，任何人都可以看到，为什么这是我的code崩溃？

Unfortunately my code is crashing when I try to save the Diner object and pass it to the main activity, can anyone see why this is?

推荐答案

使用数据的第三个参数的onActivityResult 方法而不是 getIntent（）用于获取意图，它是由使用 startActivityForResult 开始活动发送的数据：

Use data third parameter of onActivityResult method instead of getIntent() for getting data from Intent which is sent from Activity which is started using startActivityForResult :

Diner newDiner = data.getParcelableExtra("newDiner");

这篇关于传球意图之间Parcelable对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！