用Singleton实例填充ListView

Question

我知道这个问题对于大多数人来说可能是愚蠢的，但是我仍然需要帮助。

我正在尝试使用具有Singleton实例的fragents填充和ArrayList（或者至少是我所理解的我要做的事情）

我有一个填写表格，用户必须在其中填写以下信息：

 @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_formulari, container, false);

    titolET = view.findViewById(R.id.titolAnunciET);
    cuantaGenteET = view.findViewById(R.id.quantitatGentET);
    horaET = view.findViewById(R.id.horaET);
    queBirraRB = view.findViewById(R.id.birraRB);
    queCafeRB = view.findViewById(R.id.cafeRB);
    comidaSW = view.findViewById(R.id.ComerSW);

    postBT = view.findViewById(R.id.introBT);

    postBT.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            postInformation();

        }
    });
    return inflater.inflate(R.layout.fragment_formulari, container, false);


}


@Override
public void onResume() {
    super.onResume();
    setInformation();
}

public void setInformation() {

    tituloString = titolET.getText().toString();
    cuantaGenteSrting = cuantaGenteET.getText().toString();
    cafe = queCafeRB.isChecked();
    birra = queBirraRB.isChecked();
    comida = comidaSW.isChecked();
    horaString = horaET.getText().toString();

    if (cafe) {
        cafeSiNo = "Beben cafe o refrescos";
    } else {
        cafeSiNo = "No beben cafe o refrescos";
    }
    if (birra) {
        birraSiNo = "Beben birra";
    } else {
        birraSiNo = "No beben birra";
    }
    if (comida) {
        comidaSiNo = "Estan comiendo";
    } else {
        comidaSiNo = "No estan comiendo";
    }

    System.out.print(tituloString);


    respostesFormulari = new RespostesFormulari(tituloString);
    respostesFormulari.setTitol(tituloString);
    respostesFormulari.setQuantaGent(cuantaGenteSrting);
    respostesFormulari.setHora(horaString);
    respostesFormulari.setQueBirra(birraSiNo);
    respostesFormulari.setQueCafe(cafeSiNo);
    respostesFormulari.setMenjarBool(comidaSiNo);

    formulariSingleton = FormulariSingleton.getInstance();
    formulariSingleton.add(respostesFormulari);


}

我也有此类RespostesFormulari.java：

public class RespostesFormulari {

 private String titol;
 private String quantaGent;
 private String queBirra;
 private String queCafe;
 private String menjarBool;
 private String hora;

 public RespostesFormulari(String titol){this.titol = titol;}

public RespostesFormulari(String titol, String finalquantaGent, String finalqueBirra, String finalqueCafe, String finalmenjarBool, String finalHora) {
    this.titol = titol;
    this.quantaGent = finalquantaGent;
    this.queBirra = finalqueBirra;
    this.queCafe = finalqueCafe;
    this.menjarBool = finalmenjarBool;
    this.hora = finalHora;



}

public String getTitol(){
    return this.titol;
}

public void setTitol(String titol){
    this.titol = titol;

}
public String getQuantaGent() {
    return this.quantaGent;
}

public void setQuantaGent(String quantaGent) {
    this.quantaGent = quantaGent;
}

public String getQueBirra() {
    return this.queBirra;
}

public void setQueBirra(String queBirra) {
    this.queBirra = queBirra;
}

public String getQueCafe() {
    return this.queCafe;
}

public void setQueCafe(String queCafe) {
    this.queCafe = queCafe;
}

public String getMenjarBool() {
    return this.menjarBool;
}

public void setMenjarBool(String menjarBool) {
    this.menjarBool = menjarBool;
}

public String getHora() {
    return this.hora;
}

public void setHora(String hora) {
    this.hora = hora;
}

}

这是我的Singleton，我在这里管理我的RespostesFormulari.java：

FormulariSingleton类{

private RespostesFormulari respostesFormulari;
private static final FormulariSingleton formulariSingletonInstance = new FormulariSingleton();
public ArrayList<RespostesFormulari> respostesFormularisLlista;

public String titolAnunci;


public static FormulariSingleton getInstance() {
    return formulariSingletonInstance;
}


private FormulariSingleton(){
    respostesFormularisLlista = new ArrayList<RespostesFormulari>();
    respostesFormulari = new RespostesFormulari("","","","","","");
    //respostesFormularisLlista.add(new RespostesFormulari("","",false,false,false,""));
}



public ArrayList<RespostesFormulari> getLlista(){
    return this.respostesFormularisLlista; }

public void setRespostesFormulari(RespostesFormulari rf){
    this.respostesFormulari = rf; }

public void add(RespostesFormulari newRespostes){
    this.respostesFormularisLlista.add(newRespostes);}

public void delete(RespostesFormulari newRespostes){
    this.respostesFormularisLlista.remove(newRespostes);}




public void getTitolAnunci(RespostesFormulari titol) {
    titolAnunci = titol.getTitol();}





public void setClickedAnunci(RespostesFormulari anunci){
    respostesFormulari = anunci;
}
public RespostesFormulari getClickedAnunci(){
    return respostesFormulari;
}

最后，这是我的ListView类：

public class LlistaFragment extends Fragment {

public ListView listview;

ArrayAdapter<RespostesFormulari> adapter;
// ArrayList<> llista

private OnFragmentInteractionListener fListener;


public LlistaFragment() {


}

public static LlistaFragment newInstance(String param1, String param2) {
    LlistaFragment fragment = new LlistaFragment();
    Bundle args = new Bundle();
    fragment.setArguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if(getArguments() != null) {
    }
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
   // return super.onCreateView(inflater, container, savedInstanceState);
    View rootView = inflater.inflate(R.layout.fragment_llistat, container, false);

    listview = rootView.findViewById(R.id.llistView);

   // ArrayList<RespostesFormulari> llista = FormulariSingleton.getInstance().getLlista();

    adapter = new ArrayAdapter<RespostesFormulari>(getActivity(), android.R.layout.simple_list_item_1, FormulariSingleton.getInstance().getLlista());

    listview.setAdapter(adapter);
    listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            FormulariSingleton formulariSingleton = FormulariSingleton.getInstance();
            RespostesFormulari item = (RespostesFormulari) parent.getItemAtPosition(position);
            formulariSingleton.getTitolAnunci(item);
            formulariSingleton.setClickedAnunci(item);




            Intent intent = new Intent(getActivity(), DetallAnunci.class);
            intent.putExtra("Titol", position);

            /*intent.putExtra("Titol", item.getTitol());
            intent.putExtra("Numero gente", item.getQuantaGent());
            intent.putExtra("Beben birra?",item.getQueBirra());
            intent.putExtra("Beben cafe o refresco?", item.getQueCafe());
            intent.putExtra("Estan comiendo?", item.getMenjarBool());
            intent.putExtra("A que hora se van?", item.getHora());*/


            startActivity(intent);
        }
    });
    return rootView;


}

当我进入每个项目时，没有显示任何信息，并且与listView标题相同。

有什么主意吗？

非常感谢

Answer 1

最后，我设法为自己提供了解决方案。也许有人遇到同样的问题。

因此，首先，在我的应用程序表单片段中，我创建了一个按钮来发布信息并在Singleton中设置所有内容。该按钮不起作用，因为我正在用充气机返回视图。我只需要返回视图，所以我替换了这个：

 postBT.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View view) {
        postInformation();

    }
});
return inflater.inflate(R.layout.fragment_formulari, container, false);

与此：`postBT.setOnClickListener（new View.OnClickListener（）{

    @Override
    public void onClick(View view) {
        setInformation();
        postInformation();

    }
});
return view;

` 我还添加了setInformation（）;在按钮onClick上。以前，我是在onResum（）方法中执行此操作的，该方法在填写表单之前已设置了所有信息。

最后，我意识到我在我的listview.java中而不是我自己的适配器中调用了默认适配器（ArrayAdapter），所以我替换了它：

 adapter = new ArrayAdapter<RespostesFormulari>(getActivity(), android.R.layout.simple_list_item_1, FormulariSingleton.getInstance().getLlista());

listview.setAdapter(adapter);

与此：

adapter = new Adapter(getActivity(), FormulariSingleton.getInstance().getLlista());

listview.setAdapter(adapter);

这是我的适配器的代码：

public class Adapter extends BaseAdapter {

private ArrayList<RespostesFormulari> respostesFormularis;
private Context mcontext;

//CONSTRUCTOR

public Adapter(Context mcontext, ArrayList<RespostesFormulari> respostesFormularis){
    this.mcontext=mcontext;
    this.respostesFormularis=respostesFormularis;
}

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

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

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

@Override
public View getView(int position, View convertView, ViewGroup viewGroup) {
    convertView=View.inflate(mcontext, R.layout.cella_llista,null);
    TextView titol = convertView.findViewById(R.id.titolTV);
    titol.setText(FormulariSingleton.getInstance().getLlista().get(position).getTitol());
    return convertView;
}

希望有人可以从中获利！