java - 如何使用 Intent.putParcelableArrayListExtra() 方法和 Parcelable 接口(interface)，我只想在两个 Activity 之间传输数据

Question

看看我的代码，有没有错。

Activity 一:

Intent intent = new Intent(SendActivity.this, PickContactsActivity.class);
startActivityForResult(intent, 20);

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode == RESULT_OK) {
        ArrayList<PickBean> cons = data.getParcelableArrayListExtra("data");
        for (int i = 0; i < cons.size(); i++) {
            JLog.e(LOG_TAG, "displayName:" + cons.get(i).displayName + "displayNumber" + cons.get(i).displayNumber);
        }
    }
}

Activity 二:

Intent data = new Intent();
ArrayList<PickBean> cons = new ArrayList<PickBean>();
for (int i = 0; i < conData.size(); i++) {
        cons.add(new PickBean(conData.get(i).displayName, conData.get(i).displayNumber));
    }
}
data.putParcelableArrayListExtra("data", cons);
setResult(RESULT_OK, data);
finish();

PickBean 代码:

public class PickBean implements Parcelable {
    public String displayName;
    public String displayNumber;

    public boolean selected = false;

    public PickBean() {
        super();
    }

    public PickBean(String displayName, String displayNumber) {
        super();
        this.displayName = displayName;
        this.displayNumber = displayNumber;
    }

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(displayName);
        dest.writeString(displayNumber);
    }


    public final Parcelable.Creator<PickBean> CREATOR = new Parcelable.Creator<PickBean>() { 
        @Override 
        public PickBean createFromParcel(Parcel source) { 

            return new PickBean(source.readString(), source.readString()); 
        } 

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

它总是会抛出

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=20,
result=-1, data=Intent { (has extras) }} to activity 
{com.chishacai.smscenter/com.chishacai.smscenter.SendActivity}: java.lang.NullPointerException: expected receiver of type 

com.chishacai.smscenter.bean.PickBean，但是得到了null

Caused by: java.lang.NullPointerException: expected receiver of type 
com.chishacai.smscenter.bean.PickBean, but got null

请帮我解决这个问题，谢谢。

Answer 1

传递数据:

Intent intent = new Intent(SendActivity.this, PickContactsActivity.class); 
Bundle bundle;
bundle.putParcelableArrayList("data", cons); // Be sure con is not null here
intent.putExtras(bundle);

获取数据:

 ArrayList<PickBean> arrayParents = intent.getParcelableArrayListExtra("data");

将方法 newArray 替换为:

 public final Parcelable.Creator<PickBean> CREATOR = new Parcelable.Creator<PickBean>() { 
        @Override 
        public PickBean createFromParcel(Parcel source) { 

            return new PickBean(source); 
        } 

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

 public PickBean(Parcel data) {

        this.displayName = data.readString();
        this.displayNumber = data.readString();
 }