这是我的片段类。我有一个带有虚拟数据的管理器类，以及一个扩展基本适配器的adpater类。我的片段中有错误
(questionsAdapter = new QuestionsAdapter(this, questionsManager.getAllQuestions());)
我似乎不明白这个错误。因为我在questtionsAdapter构造函数
package sandwich.playmaker.com.afterschool.fragments;
import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Spinner;
import sandwich.playmaker.com.afterschool.R;
import sandwich.playmaker.com.afterschool.adapters.QuestionsAdapter;
import sandwich.playmaker.com.afterschool.manager.QuestionsManager;
/**
* A simple {@link Fragment} subclass.
* Activities that contain this fragment must implement the
* {@link QuestionsFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {@link QuestionsFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class QuestionsFragment extends Fragment {
private ListView lvQuestions;
private EditText etSearchQuestion;
private Spinner spImportance;
private QuestionsAdapter questionsAdapter;
private QuestionsManager questionsManager;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment QuestionsFragment.
*/
// TODO: Rename and change types and number of parameters
public static QuestionsFragment newInstance(String param1, String param2) {
QuestionsFragment fragment = new QuestionsFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public QuestionsFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_questions, container, false);
etSearchQuestion = (EditText) v.findViewById(R.id.etSearchQuestion);
spImportance = (Spinner) v.findViewById(R.id.spImportance);
lvQuestions = (ListView) v.findViewById(R.id.lvQuestions);
questionsManager =new QuestionsManager();
questionsAdapter = new QuestionsAdapter(this, questionsManager.getAllQuestions());
lvQuestions.setAdapter(questionsAdapter);
return v;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}
这是我的经理班
public class QuestionsManager {
private ArrayList<QuestionsModel>allQuestions;
public QuestionsManager() {
this.allQuestions = allQuestions;
}
public ArrayList<QuestionsModel>getAllQuestions(){
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Banku", "Food",
"9:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Kenkey", "Food",
"9:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Rice", "Food",
"10:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Kelewele", "Food",
"11:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Orange", "Food",
"12:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Banana", "Food",
"13:00pm"));
allQuestions.add(new QuestionsModel(R.drawable.monarki, "How to eat Gob3", "Food",
"14:40pm"));
return allQuestions;
}
}
这是我的适配器类
public class QuestionsAdapter extends BaseAdapter {
private Context ctx;
//private QuestionsModel questionsModel;
private ArrayList<QuestionsModel>allQuestions;
public QuestionsAdapter(Context ctx, ArrayList<QuestionsModel> allQuestions) {
this.ctx = ctx;
this.allQuestions = allQuestions;
// this.questionsModel = questionsModel;
}
@Override
public int getCount() {
return allQuestions.size();
}
@Override
public Object getItem(int position) {
return allQuestions.get(position);
}
@Override
public long getItemId(int position)
{
return allQuestions.get(position).getIvProfilePic();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
QuestionsModel questionsModel = allQuestions.get(position);
LayoutInflater inflater= (LayoutInflater) ctx.getSystemService(Context
.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.activity_questions, null);
ImageView ivProfilePic = (ImageView) convertView.findViewById(R.id.ivProfilePic);
TextView tvQuestion = (TextView) convertView.findViewById(R.id.tvQuestion);
TextView tvTag = (TextView) convertView.findViewById(R.id.tvQuestion);
TextView tvTime= (TextView) convertView.findViewById(R.id.tvQuestion);
ivProfilePic.setImageResource(questionsModel.getIvProfilePic());
tvQuestion.setText(questionsModel.getTvQuestion());
tvTag.setText(questionsModel.getTvQuestion());
tvTime.setText(questionsModel.getTvTime());
return convertView;
}
}
答案 0 :(得分：3)
您实际上从未将allQuestions设置为任何实例。
public QuestionsManager() {
this.allQuestions = allQuestions;
}
应该是
public QuestionsManager() {
allQuestions = new ArrayList<QuestionsModel>();
}
此外，对未来有一些建议：尝试阅读堆栈跟踪。
由于您似乎在理解如何撰写问题时遇到问题，因此让每个人都知道此行存在错误也会有所帮助：
questionsAdapter = new QuestionsAdapter(this, questionsManager.getAllQuestions());
这说明了以下内容：
Incompatible types. Required: android.app.Context. Found: blah blah blah my fragment
将违规行更改为：
questionsAdapter = new QuestionsAdapter(getActivity(), questionsManager.getAllQuestions());
Fragment不是Context，而是Activity。