Question

我一直在关注一些教程来检索json数据并使用volley将其添加到listview中。我一直陷入这个错误试图解决它一段时间，所以我不得不寻求一些帮助。我尝试了很多例子，这个看起来最直观，但我不能通过这个错误，谢谢

这是我的模特课

public class Trilhos {
private int id;
private String titulo;
private int id_user;
private String dificuldade;


public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getTitulo() {
    return titulo;
}

public void setTitulo(String titulo) {
    this.titulo = titulo;
}

public int getId_user() {
    return id_user;
}

public void setId_user(int id_user) {
    this.id_user = id_user;
}

public String getDificuldade() {
    return dificuldade;
}

public void setDificuldade(String dificuldade) {
    this.dificuldade = dificuldade;
}


}

我的适配器

public class AdapterTrilhos extends BaseAdapter {
private Activity activity;

private LayoutInflater inflater;
private List<Trilhos> triList;



public AdapterTrilhos(List<Trilhos> triList, Activity activity) {
    this.activity = activity;
    this.triList = triList;

}


@Override
public int getCount() {
    return this.triList.size();
}

@Override
public Object getItem(int position) {
    return this.triList.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {


    if (inflater == null)
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    if (convertView == null)

            convertView = inflater.inflate(R.layout.dadoslista, null);

            TextView idtxt = (TextView) 
convertView.findViewById(R.id.txtid);

            TextView tittxt = (TextView) 
convertView.findViewById(R.id.txttit);

            TextView usertxt = convertView.findViewById(R.id.txtuser);

            TextView diftxt = (TextView) 
convertView.findViewById(R.id.txtdif);

            Trilhos t = triList.get(position);

            idtxt.setText(t.getId());
            tittxt.setText(t.getTitulo());
            usertxt.setText(t.getId_user());
            diftxt.setText(t.getDificuldade());


        return convertView;
    }

}

我的main_activity（listarTrilhos）

public class ListarTrilhos extends Activity {


private static final String 
urlget="http://192.168.1.68/loginsignup/getTrilhos.php";
private ListView listView;
private AdapterTrilhos adapter;

private List<Trilhos> TrilhosList = new ArrayList<Trilhos>();



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.listatrilhos);
    listView=findViewById(R.id.listv);

   adapter=new AdapterTrilhos(this,TrilhosList);
   listView.setAdapter(adapter);


criarLista();
}

public void criarLista(){
RequestQueue mRequestQueue = 
Volley.newRequestQueue(getApplicationContext());
JsonArrayRequest request = new JsonArrayRequest(
        urlget,
        new Response.Listener<JSONArray>(){

            @Override
            public void onResponse(JSONArray response) {
                int count = response.length();
                for(int i = 0; i < count; i++){
                    try {

                        JSONObject jo = response.getJSONObject(i);
                        Trilhos tri=new Trilhos();
                        tri.setId(jo.getInt("id"));
                        tri.setTitulo(jo.getString("titulo"));
                        tri.setId_user(jo.getInt("id_user"));
                        tri.setDificuldade(jo.getString("dificuldade"));
                        TrilhosList.add(tri);





                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }


                }

                Toast.makeText(getApplicationContext(), response.toString(), 
Toast.LENGTH_LONG).show();
                adapter.notifyDataSetChanged();
            }
        },
        new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(getApplicationContext(), "onErrorResponse", 
Toast.LENGTH_LONG).show();
            }
        }
);
Object TAG_REQUEST_QUEUE = new Object();
    request.setTag(TAG_REQUEST_QUEUE);
    mRequestQueue.add(request);
    mRequestQueue.start();
}
}

Answer 1

我没有阅读你的所有代码，但注意到你有构造函数

public AdapterTrilhos(List<Trilhos> triList, Activity activity) {
this.activity = activity;
this.triList = triList;}

将adapter=new AdapterTrilhos(this, TrilhosList);更改为 adapter=new AdapterTrilhos(TrilhosList, this);

Json凌空列表视图错误不兼容类型适配器

1 个答案: