android - 自定义ListView滚动重复数据

标签 android listview

我正在经历一个相当烦人的问题。我在论坛中访问过许多针对同一问题的问题解决方案,但无法为我工作。我正在使用我创建的适配器加载 ListView。我显示的数据来 self 的数据库。列表中的每个单元格都有一个按钮可以单击,调用一个函数来编辑数据库中记录的字段。当此 listView 中的就绪记录正常时,​​但当我向下查看 listview 时,某些数据开始发生变化。有一次,我评估我的项目是否经过验证(是数据库的一个字段,如果经过验证,它可以是 0 或 1)。如果它被验证,该按钮将加载背景作为图像并取消该 denuevo 单击它。如果该值被验证为 0,我为此按钮创建了一个点击事件。然后,当我向下移动时,listView 图片按钮开始改变,即使在下方和爬升时也发生了变化,但不同之处在于,如果我可以点击它们。我不明白,因为当我在注册表值处于预定值之前进行验证时,它们会更改图像。我会让我的代码。

我的类适配器

@SuppressLint("InflateParams")
public class CustomListViewAdapter extends ArrayAdapter<RowItem> {

Context context;
private ArrayList<RowItem> items;
LayoutInflater mInflater;

public CustomListViewAdapter(Context context, int resourceId,
        List<RowItem> items) {
    super(context, resourceId, items);
    this.context = context;
    this.items = new ArrayList<RowItem>();
    this.items.addAll(items);
    this.mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
}

static class ViewHolder {
    TextView txtNombre;
    TextView txtTicket;
    TextView txtAsiento;
    TextView txtOrden;
    TextView txtNumero;
    TextView txtMensaje;
    TextView txtAdicionales;
    TextView txtOtros;
    TextView txtCategoria;
    Button btn;
}

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

@Override
public RowItem getItem(int position) {
    return items.get(position);
}

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

@Override
public View getView(int position, View convertView, final ViewGroup parent) {
    final ViewHolder holder;
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.lista_validacion_multiple, null);
        holder = new ViewHolder();
        holder.txtNombre = (TextView)convertView.findViewById(R.id.txtNombre);
        holder.txtAsiento = (TextView)convertView.findViewById(R.id.txtAsiento);
        holder.txtTicket = (TextView)convertView.findViewById(R.id.txtTicket);
        holder.txtNumero = (TextView)convertView.findViewById(R.id.txtNumero);
        holder.txtOrden = (TextView)convertView.findViewById(R.id.txtOrden);
        holder.txtAdicionales = (TextView)convertView.findViewById(R.id.txtAdicionales);
        holder.txtOtros = (TextView)convertView.findViewById(R.id.txtOtros);
        holder.txtCategoria = (TextView)convertView.findViewById(R.id.txtCategoria);
        holder.btn = (Button)convertView.findViewById(R.id.button1);
        holder.txtMensaje = (TextView)convertView.findViewById(R.id.txtMensaje);
        convertView.setTag(holder);
    } else{
        //Whenever recycling Holder, the elements begin to change in  the values that I mentioned.
        holder = (ViewHolder) convertView.getTag();
    }
    RowItem rowItem = getItem(position);
    SessionManager manager = new SessionManager();
    String codigoEvento = manager.getValue(parent.getContext(), "codigoEvento");
    holder.txtOrden.setText(Html.fromHtml("Orden de compra: <b>"+codigoEvento+"-"+rowItem.getId_inscripcion()+"</b>"));
    if (!rowItem.getAsiento().equals("") && !rowItem.getAsiento().equals("null") && rowItem.getAsiento() != null) {
        holder.txtAsiento.setText(Html.fromHtml("Asiento: <b>"+rowItem.getAsiento()+"</b>"));
        holder.txtAsiento.setVisibility(View.VISIBLE);
    }
    if (!rowItem.getNumero().equals("") && !rowItem.getNumero().equals("null") && rowItem.getNumero() != null) {
        holder.txtNumero.setText(Html.fromHtml("Número: <b>"+rowItem.getNumero()+"</b>"));
        holder.txtNumero.setVisibility(View.VISIBLE);
    }
    if (!rowItem.getAdicionales().equals("") && !rowItem.getAdicionales().equals("null") && rowItem.getAdicionales() != null) {
        holder.txtAdicionales.setText(Html.fromHtml("Adicionales: <b>"+rowItem.getAdicionales()+"</b>"));
        holder.txtAdicionales.setVisibility(View.VISIBLE);
    }
    if (!rowItem.getOtros().equals("") && !rowItem.getOtros().equals("null") && rowItem.getOtros() != null) {
        holder.txtOtros.setText(Html.fromHtml("Otros: <b>"+rowItem.getOtros()+"</b>"));
        holder.txtOtros.setVisibility(View.VISIBLE);
    }
    if(rowItem.getCategoria() != null){
        if (!rowItem.getCategoria().equals("") && !rowItem.getCategoria().equals("null") && rowItem.getCategoria() != null || !rowItem.getCategoria().isEmpty()) {
            holder.txtCategoria.setText(Html.fromHtml("Categoría: <b>"+rowItem.getCategoria()+"</b>"));
            holder.txtCategoria.setVisibility(View.VISIBLE);
        }
    }
    //Adicionales y otros
    if(rowItem.getValidado()==1){
            holder.btn.setBackgroundResource(R.drawable.icon_big_alert);
            holder.btn.setText("");
            holder.txtMensaje.setText("E-ticket ya validado");
            holder.txtMensaje.setVisibility(View.VISIBLE);
            RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int)LayoutParams.WRAP_CONTENT, (int)LayoutParams.WRAP_CONTENT);
            params.width = 50;
            params.height = 50;
            params.rightMargin = 63;
            params.topMargin = 10;
            params.bottomMargin = 5;
            params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
            holder.btn.setLayoutParams(params);
    }else{
        holder.btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                RelativeLayout layout=(RelativeLayout) v.getParent();
                int position=(Integer)v.getTag();
                RowItem item_click = getItem(position);
                Button b = (Button)v.findViewById(R.id.button1);
                TextView t=(TextView)layout.findViewById(R.id.txtMensaje);
                t.setText("E-ticket validado");
                Activity activity = (Activity)CustomListViewAdapter.this.getContext();
                TextView ts = (TextView)(activity.findViewById(R.id.txtDisponibles));
                t.setText("E-ticket validado");
                t.setVisibility(View.VISIBLE);
                b.setBackgroundResource(R.drawable.icon_big_check);
                b.setText("");
                RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int)LayoutParams.WRAP_CONTENT, (int)LayoutParams.WRAP_CONTENT);
                params.width = 50;
                params.height = 50;
                params.rightMargin = 63;
                params.topMargin = 10;
                params.bottomMargin = 5;
                params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
                b.setLayoutParams(params);
                SessionManager manager = new SessionManager();
                BaseDeDatos nueva = new BaseDeDatos();
                nueva.validarMultiple(activity, item_click);
                int validadas = manager.getValueInt(parent.getContext(), "validadas");
                int totales = manager.getValueInt(parent.getContext(), "totales");
                if(validadas > 0){
                    validadas = validadas - 1;
                    manager.setValueInt(parent.getContext(), "validadas", validadas);
                    manager.setValueInt(parent.getContext(), "totales", totales);
                    ts.setText(validadas+"/"+totales);
                }
            }
        });

    }
    return convertView;
   }
}

布局列表:

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

<TextView
    android:id="@+id/txtNombre"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_marginTop="10dp"
    android:paddingLeft="10dp"
    android:text="TextView" />

<TextView
    android:id="@+id/txtTicket"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtNombre"
    android:paddingLeft="10dp"
    android:text="TextView" />

<TextView
    android:id="@+id/txtOrden"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtTicket"
    android:paddingLeft="10dp"
    android:text="" />

<TextView
    android:id="@+id/txtAsiento"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtOrden"
    android:paddingLeft="10dp"
    android:visibility="gone"
    android:text="" />

 <TextView
    android:id="@+id/txtNumero"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtAsiento"
    android:paddingLeft="10dp"
    android:visibility="gone"
    android:text="" />

 <TextView
    android:id="@+id/txtAdicionales"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtNumero"
    android:paddingLeft="10dp"
    android:visibility="gone"
    android:text="" />

 <TextView
    android:id="@+id/txtOtros"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtAdicionales"
    android:paddingLeft="10dp"
    android:visibility="gone"
    android:text="" />

 <TextView
    android:id="@+id/txtCategoria"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/txtOtros"
    android:paddingLeft="10dp"
    android:visibility="gone"
    android:text="" />

<Button
    android:id="@+id/button1"
    style="?android:attr/buttonStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/txtOrden"
    android:layout_alignParentRight="true"
    android:layout_marginRight="23dp"
    android:background="@drawable/btn_green_small"
    android:maxHeight="48dp"
    android:maxWidth="80dp"
    android:shadowColor="#A8A8A8"
    android:text="Validar"
    android:textColor="#FFFFFF" />

<TextView
    android:id="@+id/txtMensaje"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/button1"
    android:text="SDSDSDS"
    android:layout_marginRight="18dp"
    android:visibility="gone"
    android:textSize="10dp" />

 </RelativeLayout>

最佳答案

这是因为 View 回收。当适配器需要在您的列表中显示一个新元素时有两种可能性:

  1. 创建一个新元素:此元素具有布局的默认值。
  2. 重用不再可见的元素:此元素具有旧值。

因此,您需要在 getView 中将正确的值放入您的列表元素中。如果 rowItem.getValidado()!=1 您将 OnClickListener 设置为您的按钮,但您没有为正确的按钮更改背景,则您没有使用您的按钮执行此操作.

您可以在 RowItem 中添加一个字段来保存状态并恢复 getView 中字段的状态。像这样:

 if(rowItem.getClicked()){
     holder.btn.setBackgroundResource(R.drawable.icon_big_check);
     holder.btn.setOnClickListener(null);
}else if(rowItem.getValidado()==1){
            holder.btn.setBackgroundResource(R.drawable.icon_big_alert);
            holder.btn.setText("");
            holder.txtMensaje.setText("E-ticket ya validado");
            holder.txtMensaje.setVisibility(View.VISIBLE);
            RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int)LayoutParams.WRAP_CONTENT, (int)LayoutParams.WRAP_CONTENT);
            params.width = 50;
            params.height = 50;
            params.rightMargin = 63;
            params.topMargin = 10;
            params.bottomMargin = 5;
            params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
            holder.btn.setLayoutParams(params);

            holder.btn.setOnClickListener(null);
    }else{
        holder.btn.setBackgroundResource(R.drawable.btn_green_small);

        holder.btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               rowItem.setClicked(true);

                RelativeLayout layout=(RelativeLayout) v.getParent();
                int position=(Integer)v.getTag();
                RowItem item_click = getItem(position);
                Button b = (Button)v.findViewById(R.id.button1);
                TextView t=(TextView)layout.findViewById(R.id.txtMensaje);
                t.setText("E-ticket validado");
                Activity activity = (Activity)CustomListViewAdapter.this.getContext();
                TextView ts = (TextView)(activity.findViewById(R.id.txtDisponibles));
                t.setText("E-ticket validado");
                t.setVisibility(View.VISIBLE);
                b.setBackgroundResource(R.drawable.icon_big_check);
                b.setText("");
                RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int)LayoutParams.WRAP_CONTENT, (int)LayoutParams.WRAP_CONTENT);
                params.width = 50;
                params.height = 50;
                params.rightMargin = 63;
                params.topMargin = 10;
                params.bottomMargin = 5;
                params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
                b.setLayoutParams(params);
                SessionManager manager = new SessionManager();
                BaseDeDatos nueva = new BaseDeDatos();
                nueva.validarMultiple(activity, item_click);
                int validadas = manager.getValueInt(parent.getContext(), "validadas");
                int totales = manager.getValueInt(parent.getContext(), "totales");
                if(validadas > 0){
                    validadas = validadas - 1;
                    manager.setValueInt(parent.getContext(), "validadas", validadas);
                    manager.setValueInt(parent.getContext(), "totales", totales);
                    ts.setText(validadas+"/"+totales);
                }
            }
        });
        }

关于android - 自定义ListView滚动重复数据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35609443/

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