Question

我正在填充包含ImageView和TextView的ListView。它没有崩溃，但也没有显示任何东西。我看到了很多教程，但似乎显示的是与我使用的相同的代码。

这是row.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/fondo_fila_click"
    android:orientation="horizontal"
    android:padding="5dip" >

    <LinearLayout android:id="@+id/thumbnail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="3dip"
        android:layout_alignParentLeft="true"
        android:background="@drawable/borde_foto"
        android:layout_marginRight="5dip">

        <ImageView
            android:id="@+id/imagen_marca"
            android:layout_width="50dip"
            android:layout_height="50dip"/>

    </LinearLayout>

    <TextView
        android:id="@+id/nombre"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/thumbnail"
        android:layout_toRightOf="@+id/thumbnail"
        android:textColor="#040404"
        android:typeface="sans"
        android:textSize="15dip"
        android:textStyle="bold"/>


</RelativeLayout>

代码：

   public class SATActivity extends SherlockListActivity {

private IconListViewAdapter adaptador;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);  

        ArrayList m_fabricante = new ArrayList();
        this.adaptador = new IconListViewAdapter(this, R.layout.fila, m_fabricante);
        setListAdapter(this.adaptador);         
        iniciaFabricantes();         
    }

    @SuppressWarnings("unchecked")
    private void iniciaFabricantes() {
        ArrayList m_fabricante = new ArrayList();

        try {
            Fabricante acer = new Fabricante();
            acer.setNombre("Acer");
            acer.setFoto(R.drawable.acer);
            Fabricante apple = new Fabricante();
            apple.setNombre("Apple");
            apple.setFoto(R.drawable.apple);

            m_fabricante.add(acer);
            m_fabricante.add(apple);
        } catch (Exception e) {

        }

        adaptador.notifyDataSetChanged();
    } 

    public class IconListViewAdapter extends ArrayAdapter<Fabricante> {

        private ArrayList<Fabricante> items;

        public IconListViewAdapter(Context context, int textViewResourceId, ArrayList<Fabricante> items) {
            super(context, textViewResourceId, items);
            this.items = items;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = convertView;
            if (v == null) {
                LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                v = vi.inflate(R.layout.row, null);
            }

            Fabricante o = items.get(position);
            if (o != null) {

                //poblamos la lista de elementos

                TextView tt = (TextView) v.findViewById(R.id.nombre);
                ImageView im = (ImageView) v.findViewById(R.id.imagen_marca);

                if (im!= null) {
                    im.setImageResource(o.getFoto());
                }      

                if (tt != null) {             
                    tt.setText(o.getNombre());                             
                }                                                       
            }
            return v;
        }
    }   
}

有谁知道为什么它不显示文字或图像？

由于

Answer 1

尝试将适配器类更改为低于1：

public class IconListViewAdapter extends ArrayAdapter<Fabricante> {

        private ArrayList<Fabricante> items;
        LayoutInflater mInflater;

        public IconListViewAdapter(Context context, int textViewResourceId, ArrayList<Fabricante> items) {
            super(context, textViewResourceId, items);
            this.items = items;
            mInflater = LayoutInflater.from(context);
        }

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

            final ViewHolder holder; 

            if (convertView == null) {
                convertView = mInflater.inflate(R.layout.row, null);
                holder = new ViewHolder();

                holder.mTextView=(TextView)convertView.findViewById(R.id.nombre);
                holder.mImageView=(ImageView)convertView.findViewById(R.id.imagen_marca);
                convertView.setTag(holder);
            }
            else
                holder=(ViewHolder)convertView.getTag();

            Fabricante o = items.get(position);
            if (o != null) {

                //poblamos la lista de elementos

                holder.mImageView.setImageResource(o.getFoto());

                holder.mTextView.setText(o.getNombre());                             

            }
            return convertView;
        }
        static class ViewHolder
        {                
            TextView mTextView;
            ImageView mImageView;
        }    

    }

Answer 2

在 getView 方法中，进行以下更改：

if (im!= null) {
  Drawable d = context.getResources().getDrawable(o.getFoto());
  d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());//must require

  if(d!=null)
     im.setImageDrawable(d);
  else
     Log.w("listview", "drawable is not available");
}

希望它应该有用。

Answer 3

尝试添加ViewHolder以及在if语句中调用findViewById，在其中展开视图。 http://www.vogella.de/articles/AndroidListView/article.html#overview应该有助于您的自定义适配器。

带有ImageView和TextView的ListView没有显示任何内容

3 个答案: