Passing and ArrayList through intent

问题:

I have a class called Service, which is used to create Service objects using this constructor

public Service(int id, String service_name, String service_code) {
    this.id = id;
    this.service_name = service_name;
    this.service_code = service_code;
}

then I create a list call service list as with the following signature

List<Service> serviceList = new ArrayList<Service>

I have try to pass this ArrayList through Intent Object like this

Intent i = new Intent(Classname.this, anotherClass.class);
i.putExtras("serviceList",serviceList);
startActivity(i);

But it fails. What is the way I pass through intent with ArrayList object.

回答1:

Your custom class has to implement Parcelable or Serializable in order to serialize/de-serialize within an Intent.

Your class Service has to look like this for example (used a generator http://www.parcelabler.com/)

public class Service implements Parcelable {
private int id;
private String service_name;
private String service_code;
public Service(int id, String service_name, String service_code) {
this.id = id;
this.service_name = service_name;
this.service_code = service_code;
}


protected Service(Parcel in) {
    id = in.readInt();
    service_name = in.readString();
    service_code = in.readString();
}

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

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeInt(id);
    dest.writeString(service_name);
    dest.writeString(service_code);
}

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

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

}

Then you can use getIntent().getParcelableArrayListExtra() with casting

ArrayList<Service> serviceList= intent.<Service>getParcelableArrayList("list"));

For sending you use it like this

intent.putParcelableArrayListExtra("list", yourServiceArrayList);

Note that the yourServiceArrayList should be an ArrayList

if it is List the you can pass through

intent.putParcelableArrayListExtra("list", (ArrayList<? extends Parcelable>) yourServiceArrayList);

回答2:

You can use parcelable interface for 'Service' class, and send object through

intent using 'putParcelableArrayListExtra' method and to retrive data you can use

'getParcelableArrayListExtra'.

For your reference refer this link

回答3:

Implement object class with Serializable . eg.

class abc implements Serializable{
//your code
}

then try this code

ArrayList<abc> fileList = new ArrayList<abc>();
Intent intent = new Intent(MainActivity.this, secondActivity.class);
 intent.putSerializable("arraylisty",filelist);
startActivity(intent);

and on other side receive intent like

your arraylist objact=intent.getSerializableExtra(String name)