将ArrayList从Fragment类传递到Activity

Question

我有主片段，我想传递ArrayList到Activity类，我将在ListView中显示结果。

片段类:

public class StudentActivity extends Fragment implements OnClickListener {
}

I have data

ArrayList<> allStudents = new ArrayList();
allStudents.add(new Student("H", 99, 93) );    
allStudents.add(new Student("C", 98, 92) );
allStudents.add(new Student("B", 98, 91) );    
allStudents.add(new Student("A", 80, 94) );
allStudents.add(new Student("F", 70, 84) );

现在我想发送"allStudents"对象到新的活动类StudentResult();

我使用在片段类:

Intent intent = new Intent(getActivity(), StudentResult.class);
intent.putExtra("ExtraData", allStudents);
startActivity(intent);

和在目标类中显示ListView()中的对象;

public class ResultActivity extends Activity {
    public void myData(ArrayList<allStudents> myArray) {
    marjslistview = (ListView) findViewById(R.id.listView1);
    arrayAdapter = new ArrayAdapter<allStudents>(this, R.layout.student_list, myArray);
    ...
    ScoreLV.setAdapter(arrayAdapter);
    ...
    }
}

提前感谢!

Answer 1

在Fragment中创建自定义接口:

public interface OnFragmentInteractionListener {    
    public void onFragmentSetStudents(ArrayList<Student>);         
}

在Activity中实现这个接口:

public class YourActivity extends Activity implements YourFragment.OnFragmentInteractionListener {
   private ArrayList<Student> allStudents;
}

现在你必须重写声明的方法(在你的Activity):

@Override
public void onFragmentSetStudents(ArrayList<Student> students) {
  allStudents = students;
}

然后你只需要在你的Fragment中启动这个方法:

OnFragmetInteractionListener listener = (OnFragmentInteractionListener) activity;
listener.onFragmentStudents(allStudents)

Answer 2

在你的Activity:

Bundle bundle = getIntent().getExtras(); 
ArrayList allStudents = bundle.get("ExtraData");

，我认为你需要定义你的ArrayAdapter为:

arrayAdapter = new ArrayAdapter<Student>(this, R.layout.student_list, allStudents);

剩下的代码，只需添加上面的代码。