将 parcelables 数组列表传递给不同的 activity？

Question

我有一个 class 胆固醇监测器，它实现了 parcelable。在我的 activity 中，我尝试通过意图将 parcelables 数组列表传递给另一个 activity。我这样初始化我的监视器列表：

 private ArrayList<? extends Parcelable> monitor_list;

那我传过去：

 monitor_list = patientListFragment.getMonitorList();
Intent intent = new Intent(this, CholesterolMonitorActivity.class);
            intent.putParcelableArrayListExtra("monitorList" ,monitor_list);
            startActivity(intent);

我的获取监控列表方法returns胆固醇监控器数组列表：

 public ArrayList<CholesterolMonitor> getMonitorList(){
    return this.monitorList;
}

在我的接收中activity我有两个数组列表，

private ArrayList<? extends Parcelable> monitor_list;
private ArrayList<CholesterolMonitor>cholesterol_monitor;

monitor_list= this.getIntent().getParcelableArrayListExtra("monitorList");

 this.cholesterol_monitor = (ArrayList<CholesterolMonitor>) monitor_list;

但是，应用程序在这个活动启动时崩溃了？这是错误日志。

Process: com.example.safeheart, PID: 22778
java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.List org.hl7.fhir.dstu3.model.Patient.getName()' on a null object reference
    at com.example.safeheart.patientList.MonitorListRecyclerAdapter.onBindViewHolder(MonitorListRecyclerAdapter.java:41)
    at com.example.safeheart.patientList.MonitorListRecyclerAdapter.onBindViewHolder(MonitorListRecyclerAdapter.java:20)
    at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder

Answer 1

你可以像下面那样做

像下面这样创建 java 对象

public class ClassMyModel implements Serializable {
   private ArrayList<CholesterolMonitor> cholesterolMonitorArrayList;

    public ArrayList<CholesterolMonitor> getCholesterolMonitorArrayList() {
        return cholesterolMonitorArrayList;
    }

    public void setCholesterolMonitorArrayList(ArrayList<CholesterolMonitor> cholesterolMonitorArrayList) {
        this.cholesterolMonitorArrayList = cholesterolMonitorArrayList;
    }
}

并在您的 CholesterolMonitor 中实现 Serializable Class 也

public class CholesterolMonitor implements Serializable {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

在你的Activity一个

private ArrayList<CholesterolMonitor> cholesterolMonitorArrayList = new ArrayList<>();

            CholesterolMonitor test = new CholesterolMonitor();
            test.setName("test Name");
            cholesterolMonitorArrayList.add(test);

            ClassMyModel data = new ClassMyModel();
            data.setCholesterolMonitorArrayList(cholesterolMonitorArrayList);

            Intent intent = new Intent(SignUpActivity.this, ForgotPwdEmailActivity.class);
            intent.putExtra("TEST", data);
            startActivity(intent);

在你的 Activity B

       if (getIntent() != null) {
            classMyModel = (ClassMyModel) getIntent().getSerializableExtra("TEST");
            if(classMyModel != null){
                System.out.println("Name :: "+ classMyModel.getCholesterolMonitorArrayList().get(0).getName());
            }
        }

注意：确保 ClassMyModel 的每个嵌套 class 都实现了 Serializable 接口

将 parcelables 数组列表传递给不同的 activity？

Passing an array list of parcelables to a different activity?

android

arraylist

parcelable

android-intent