使用AsyncTask更新ListView项目

Question

I have the follow scenario:

One activity that consults values from internet and fills an object below:

public class LPBean {

private Lin lin;
private Posted posted;
public Lin getLin() {
    return lin;
}
public void setLin(Lin lin) {
    this.lin = lin;
}
public Posted getPosted() {
    return posted;
}
public void setEstimativa(Posted p) {
    this.posted = p;
}
}

My activity fill the lin information in LPBean from internet and pass the object to CustomAdapter

But the posted value from LPBean is populated with information from the internet and the search key is lin.id (form LPBean),so tho do this, I'm using a AsynkTask.

Thus, the listView is showing to user and the posted values (from LpBean) are displayed dynamically with listView opened.

To do this, I make like below:

public class ListaLinsAdapter extends BaseAdapter {
    private Context context;
    private List<LinPostedBean> lins;
    private LayoutInflater inflater;
    private ViewHolder holder;
    private String idLin;

public ListaLinsAdapter(Context context, List<LinPostedBean> listaLins) {
    this.context = context;
    this.lins = listaLins;
    this.inflater = LayoutInflater.from(context);
}

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

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

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

@Override
public View getView(int position, View view, ViewGroup parent) {
    // Recupera o estado da posição atual
    LinPostedBean lpBean = lins.get(position);
    Lin lin = lpBean.getLin();
do somthing.....

and at the end of the getView method from adapter, is verified if has value to posted attribute to show the information

        if((lpBean.getPosted() != null) && (lpBean.getPosted().getPonto() != null))
    {
        if(lpBean.getPosted().getPonto().size() > 0)
            holder.fillPosted(lpBean.getPosted());
        else
            holder.showMsg(context.getResources().getString(R.string.msgEmptyPosted));
    }


    return view;
}

In my activity I have implemented the AsyncTask inner class like below:

private class ConsultaPostedBackGround extends AsyncTask<Object, Void, Object[]> {

    @Override
    protected Object[] doInBackground(Object... objs) {
            try {
                LinPostedBean lpBean = (LinPostedBean)objs[0];
                Context context = (Context)objs[3];
                String linId = lpBean.getLin().getLin();
                int indice = linId.indexOf("-");
                linId = linId.substring(0,indice).trim();
//GET INFORMATION FROM INTERNET
                PostedUtil pUtil = new PostedUtil(pontoId.trim(), linId,
                        context);

//PUT INTERNET RESULT IN Posted ATTRUBUTE IN ADAPTER
                Integer position = (Integer)objs[1];
                ((LinPostedBean)((ListaLinsAdapter)objs[2]).getItem(position)).setEstimativa(pUtil.getPosted());

            } catch (Exception e) {
                objs[3] = null;
            }
        return objs;
    }

    @Override
    protected void onPostExecute(Object[] result) {
//REFRESH LISTVIEW
        if(result[3] != null)
            ((ListaLinsAdapter)result[2]).notifyDataSetChanged();
    }

In the activity I'm call the AsyncTask one time to each lin, like below:

ListView lista = (ListView) findViewById(R.id.listView);
    lista.setAdapter(listaLinsAdapter);
    lista.setOnItemClickListener(this);

    int cont = 0;
    for (LinPostedBean lpBean : listaLPBean) {
        Object[] params = new Object[4];
        params[0] = lpBean;
        params[1] = new Integer(cont);
        params[2] = listaLinsAdapter;
        params[3] = this;
//CALL TO AsyncTask
        new ConsultaPrevisaoBackGround().execute(params);
        cont++;
    }

I think that this strategy are correct, but not working. The values of posted is not showing in listview.

What is wrong??

UPDATED

My class Adapter:

public class ListaLinsAdapter extends BaseAdapter {
private Context context;
private List<LinPostedBean> lins;
private LayoutInflater inflater;
private ViewHolder holder;
private String idLin;

public ListaLinsAdapter(Context context, List<LinPostedBean> listaLins) {
    this.context = context;
    this.lins = listaLins;
    this.inflater = LayoutInflater.from(context);
}

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

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

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

@Override
public View getView(int position, View view, ViewGroup parent) {
    // Recupera o estado da posição atual
    LinPostedBean lpBean = lins.get(position);
    Lin lin = lpBean.getLin();

    if (view == null) {
        view = inflater.inflate(R.layout.listadadoslins, null);
        holder = new ViewHolder(context);
        // Número da lin
        holder.txtIdLin = (TextView) view.findViewById(R.id.txtIdLin);
        // Nome da lin
        holder.txtNomeLin = (TextView) view
                .findViewById(R.id.txtNomeLin);

        // Seta campo de informação sem parada
        holder.txtMsgSemParada = (TextView) view
                .findViewById(R.id.msgSemParada);

        // seta layouts de previsão
        holder.llLin1 = (LinearLayout) view
                .findViewById(R.id.linearPrevisoes1);
        holder.llLin2 = (LinearLayout) view
                .findViewById(R.id.linearPrevisoes2);
        holder.llLin3 = (LinearLayout) view
                .findViewById(R.id.linearPrevisoes3);

        // Seta campos de previsão
        holder.txtPrev1 = (TextView) view.findViewById(R.id.txtPrev1);
        holder.txtPrev2 = (TextView) view.findViewById(R.id.txtPrev2);
        holder.txtPrev3 = (TextView) view.findViewById(R.id.txtPrev3);
        holder.txtPrev4 = (TextView) view.findViewById(R.id.txtPrev4);
        holder.txtPrev5 = (TextView) view.findViewById(R.id.txtPrev5);
        holder.txtPrev6 = (TextView) view.findViewById(R.id.txtPrev5);

        view.setTag(holder);
    } else {
        holder = (ViewHolder) view.getTag();
        holder.reset();
    }

    String lin = lin.getLin().trim();
    StringTokenizer stk = new StringTokenizer(lin, "-");

    // Número da lin
    idLin = stk.nextToken();
    holder.txtIdLin.setText(idLin);

    // Nome da lin
    holder.txtNomeLin.setText(stk.nextToken());

    //new ConsultaPostedBackGround().execute("");
    if((lpBean.getPosted() != null) && (lpBean.getPosted().getPonto() != null))
    {
        if(lpBean.getPosted().getPonto().size() > 0)
            holder.fillPosted(lpBean.getPosted());
        else
            holder.showMsg(context.getResources().getString(R.string.msgSemPosted));
    }


    return view;
}

static class ViewHolder {
    Context context;
    TextView txtIdLin;
    TextView txtNomeLin;
    TextView txtMsgSemParada;

    LinearLayout llLin1;
    LinearLayout llLin2;
    LinearLayout llLin3;

    TextView txtPrev1;
    TextView txtPrev2;
    TextView txtPrev3;
    TextView txtPrev4;
    TextView txtPrev5;
    TextView txtPrev6;

    public ViewHolder(Context cont) {
        this.context = cont;
    }

    public void reset() {
        txtIdLin.setText(null);
        txtNomeLin.setText(null);
        limpaPrevisoes();
    }

    private void limpaPrevisoes() {
        llLin1.setVisibility(View.GONE);
        llLin2.setVisibility(View.GONE);
        llLin3.setVisibility(View.GONE);
        txtMsgSemParada.setVisibility(View.GONE);

        txtPrev1.setText(null);
        txtPrev2.setText(null);
        txtPrev3.setText(null);
        txtPrev4.setText(null);
        txtPrev5.setText(null);
        txtPrev6.setText(null);
    }

    public void showError() {
        showMsg(context.getResources().getString(R.string.msgErroPosted));
    }

    public void showMsg(String msg) {
        limpaPrevisoes();
        txtMsgSemParada.setText(msg);
    }

    public void fillPosted(Posted p) {
        Collections.sort(p.getPonto());

        if (p.getPonto().size() > 6) {
            for (int i = 6; i < p.getPonto().size(); i++)
                p.getPonto().remove(i);
        }

        int cont = 1;
        for (Estimativa estimativa : p.getPonto()) {
            setPosted(cont, estimativa, p);
            cont++;
        }

        if (p.getPonto().size() <= 2) {
            llLin2.setVisibility(View.GONE);
            llLin3.setVisibility(View.GONE);
        }

        if ((p.getPonto().size() > 2) && (p.getPonto().size() <= 4))
            llLin3.setVisibility(View.GONE);

    }

    // Preenche o campo referente à estimativa
    private void setPosted(int id, Estimativa estimativa,
            Posted posted) {

        switch (id) {
        case 1:
            txtPrev1.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev1);
            break;
        case 2:
            txtPrev2.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev2);
            break;
        case 3:
            txtPrev3.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev3);
            break;
        case 4:
            txtPrev4.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev4);
            break;
        case 5:
            txtPrev5.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev5);
            break;
        case 6:
            txtPrev6.setText(getgetPostedFormatedPosted(posted, estimativa));
            setBackGroundColor(estimativa, txtPrev6);
            break;
        default:
            break;
        }

    }

    private String getgetPostedFormatedPosted(Posted posted,
            Estimativa estimativa) {
        String hourStr;
        String minutoStr;
        long hourAtual = Long.parseLong(posted.getHorarioAtual());
        long seconds = (estimativa.getHorarioPacote() - hourAtual) / 1000;
        int week = (int) Math.floor(seconds / 604800);
        seconds -= week * 604800;
        int dias = (int) Math.floor(seconds / 86400);
        seconds -= dias * 86400;
        int hours = (int) Math.floor(seconds / 3600);
        seconds -= hours * 3600;
        int minutes = (int) Math.floor(seconds / 60);
        seconds -= minutes * 60;

        minutes += 1;

        if (hours < 10)
            hourStr = "0" + hours;
        else
            hourStr = String.valueOf(hours);

        if (minutes < 10)
            minutoStr = "0" + minutes;
        else
            minutoStr = String.valueOf(minutes);

        String tempo;
        if (hours > 0)
            tempo = hourStr + "h " + minutoStr + "min";
        else
            tempo = minutoStr + "min";

        SimpleDateFormat spf = new SimpleDateFormat("HH:mm:ss");
        tempo = tempo + " às "
                + spf.format(estimativa.getHorarioEstimado());
        return tempo;
    }

    private void setBackGroundColor(Estimativa estimativa, TextView txtView) {
        // Imagem a ser exibida
        switch (estimativa.getStatus()) {
        case 0:
            txtView.setBackgroundColor(context.getResources().getColor(
                    R.color.postedVerde));
            break;
        case 1:
            txtView.setBackgroundColor(context.getResources().getColor(
                    R.color.postedLaranja));
            break;
        case 2:
            txtView.setBackgroundColor(context.getResources().getColor(
                    R.color.postedVermelha));
            break;
        default:
            break;
        }
    }
}
}

My xml of a item in listView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/txtIdLinha"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:paddingLeft="6dp"
        android:paddingRight="4dp"
        android:paddingTop="4dp"
        android:text="184"
        android:textColor="@color/blue_nightsky"
        android:textSize="20sp"
        android:textStyle="bold" />

    <LinearLayout
        android:id="@+id/llPrevisoes"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <LinearLayout
            android:id="@+id/linearTit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/txtNomeLinha"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingRight="7dp"
                android:text="FFFFFF"
                android:textColor="@drawable/dialog_itemtextlist_selector"
                android:textStyle="bold" >
            </TextView>

            <TextView
                android:id="@+id/msgSemParada"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingRight="7dp"
                android:text="@string/msgSemPrevisao"
                android:textColor="@drawable/dialog_itemtextlist_selector"
                android:textSize="12sp"
                android:textStyle="bold"
                android:visibility="gone" >
            </TextView>
        </LinearLayout>

        <LinearLayout
            android:id="@+id/linearPrevisoes1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="2dp">

            <TextView
                android:id="@+id/txtPrev1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>

            <TextView
                android:id="@+id/txtPrev2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>

        </LinearLayout>

        <LinearLayout
            android:id="@+id/linearPrevisoes2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="2dp" >

            <TextView
                android:id="@+id/txtPrev3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>

            <TextView
                android:id="@+id/txtPrev4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>


        </LinearLayout>

        <LinearLayout
            android:id="@+id/linearPrevisoes3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="2dp">

            <TextView
                android:id="@+id/txtPrev5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>

            <TextView
                android:id="@+id/txtPrev6"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"
                android:paddingLeft="2dp"
                android:paddingRight="2dp"
                android:text=""
                android:textColor="@color/white"
                android:textSize="12dp" >
            </TextView>

        </LinearLayout>
    </LinearLayout>

</LinearLayout>

UPDATED

Solved, the problem was in my adapter.

Answer 1

Try adding the following to your ListaLinsAdapter.

public void add(LinPostedBean lpb){
    lins.add(lpb);
    notifyDataSetChanged();
}

Then call that in doInBackground and you don't need to use onPostExecute in this case.