尝试使用时遇到的问题可以在活动之间进

Question

我到处搜索，甚至在android网页上，但我没有发现任何东西。我试图传递一个类的Arraylist：“ArrayList”从意图a到意图b，但总是我有问题，传输数据但是当脚本尝试从意图转换为parcelable或者其他什么时，我只得到“ null ”。我正在复制代码;

public class MedicalService  implements Parcelable{
    String MSrName;
    String MSrValue;
    String FnsValue;
    String Clinica;


    /*i deleted the getters and setters*/

    //------------------------PARCELABLE-----------------------
    @Override
    public int describeContents() {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        // TODO Auto-generated method stub
        dest.writeString(MSrName);
        dest.writeString(MSrValue);
        dest.writeString(FnsValue);
        dest.writeString(Clinica);
    }
    public static final Parcelable.Creator<MedicalService> CREATOR = new Parcelable.Creator<MedicalService>() {

        @Override
        public MedicalService createFromParcel(Parcel arg0) {
            // TODO Auto-generated method stub
            return new MedicalService(arg0);
        }

        @Override
        public MedicalService[] newArray(int arg0) {
            // TODO Auto-generated method stub
            return new MedicalService[arg0];
        }

    };
    public MedicalService(Parcel in){
        this();
        MSrName = in.readString();
        MSrValue = in.readString();
        FnsValue = in.readString();
        Clinica = in.readString();
    }
    public MedicalService() {
        // TODO Auto-generated constructor stub
    }
}

这是意图A

            MedicalService ms = new MedicalService(null);
            ArrayList<MedicalService>lMS = new ArrayList<MedicalService>();

            ms = xml_h.getMedicalService(session.getUsrMobileSessionCode(), idClinica , MSrCode);
            ms.setClinica(clinica);
            lMS.add(ms);


            Intent i = new Intent(User.this,Result.class);
            i.putParcelableArrayListExtra("MS_", lMS);
            startActivity(i);

这是意图B（我收到了“加注”）

  ArrayList<MedicalService> lMS = new ArrayList<MedicalService>();
    Intent intent = getIntent();
    Parcelable[] ps = intent.getParcelableArrayExtra("MS_");

我尝试了一切，有很多方法来传递信息，即使使用Serializable，但是这不允许我放置一个arraylist。当我创建这个类的一个实例时，出现一个错误，告诉我我的类需要初始化，但是使用Parcel

   ms = new MedicalService(null);