ArrayAdapter文本和图像

Question

在我的活动中,我实现了一个包含一些文件名称的列表.每个列表的项目都指的是我想要显示图像名称和引用图像缩略图的布局.我可以使用ArrayAdapter显示名称,但我不知道如何插入图像缩略图.引用的所有图像都保留在sd_card中,并且我有它们的路径.这是单行布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:orientation="horizontal" >

<ImageView
    android:id="@+id/imageView"
    android:layout_width="36dp"
    android:layout_height="wrap_content"
    android:src="@drawable/btn_nav_background_default" />

<TextView
    android:id="@+id/titoloTv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

和活动的布局

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

<Button
    android:id="@+id/creaButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:text="Crea una nuova realtà aumentata" />

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:text="Ar già create"
    android:textAppearance="?android:attr/textAppearanceLarge" />

<ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >


</ListView>

</LinearLayout>

和活动代码固有的适配器.

    ArrayAdapter<?> arrayAdapter = new ArrayAdapter<String>(this,R.layout.row,R.id.titoloTv,targetName);
    listView.setAdapter(arrayAdapter);

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {  
           @Override  
           public void onItemClick(AdapterView<?> adapter, final View componente, int pos, long id){

...................            
           } 

    }); 

我正在尝试使用它,但无法正常工作.

    String tempTarget;
    List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

   for(int i = 0; i<ARelements.size();i++){
        Element ar = arIterator.next();

        Map<String,Object> map = new HashMap<String,Object>(2);
        tempTarget = ar.getAttributeValue("TARGET");
        thumbnailBitmap = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(tempTarget), THUMBSIZE, THUMBSIZE);
        map.put("thumbnail", thumbnailBitmap);
        map.put("titolo", tempTarget);
        data.add(map);
    }
   arIterator= null;

   SimpleAdapter simpleAdapter = new SimpleAdapter(this,data,R.layout.row,new String[] {"thumbnail","titolo"},new int[] {R.id.imageView, R.id.titoloTv});


    listView.setAdapter(simpleAdapter);

Answer 1

您需要实现自定义数组适配器并在适配器中指定imageview和textview布局/ ID.

就像是:

  public class CustomListViewAdapter extends ArrayAdapter<RowItem> {


    Context context;

    public CustomListViewAdapter(Context context, int resourceId, //resourceId=your layout
            List<RowItem> items) {
        super(context, resourceId, items);
        this.context = context;
    }

    /*private view holder class*/
    private class ViewHolder {
        ImageView imageView;
        TextView txtTitle;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        RowItem rowItem = getItem(position);

        LayoutInflater mInflater = (LayoutInflater) context
                .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.list_item, null);
            holder = new ViewHolder();
            holder.txtTitle = (TextView) convertView.findViewById(R.id.title);
            holder.imageView = (ImageView) convertView.findViewById(R.id.icon);
            convertView.setTag(holder);
        } else
            holder = (ViewHolder) convertView.getTag();

        holder.txtTitle.setText(rowItem.getTitle());
        holder.imageView.setImageResource(rowItem.getImageId());

        return convertView;
    }
}  

然后:

listView = (ListView) findViewById(R.id.list);
        CustomListViewAdapter adapter = new CustomListViewAdapter(this,
                R.layout.list_item, rowItems);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(this);
    }


@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
        long id) {
    Toast toast = Toast.makeText(getApplicationContext(),
        "Item " + (position + 1) + ": " + rowItems.get(position),
        Toast.LENGTH_SHORT);
    toast.show();
}  

对于ListView及其自定义实现,请参阅扩展其他适配器:
例如. http://theopentutorials.com/tutorials/android/listview/android-custom-listview-with-image-and-text-using-arrayadapter/

Answer 2

您不一定需要自定义ArrayAdapter,SimpleAdapter将为缩略图/文本组合提供技巧.您可以在HashMap数组中存储缩略图和所需文本的路径,然后使用SimpleAdapter应用它.例如,如果您有5个缩略图+文本和每个的数组:

List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();
for (int i = 0; i < 5; i++) {
            Map<String, Object> datum = new HashMap<String, Object>(2);
            datum.put("thumbnail", thumbnail[i]);
            datum.put("name", text[i]);
            data.add(datum);
        }
YourListViewId.setAdapter(new SimpleAdapter(this, data, R.layout.yoursinglerowlayout, new String[] {"thumbnail","name"}, new int[] {R.id.imageView, R.id.titoloTv}));