可扩展列表查看组和孩子的不同图像

Question

我有基本的expandablelistview，想知道如何让每个孩子和每个小组都有不同的图像。我需要以某种方式修改可扩展列表适配器吗？任何帮助、想法、cmets 将不胜感激。谢谢:)

主活动：

    public class MainActivity extends Activity{
           .....
public static final Integer[] images = {
            R.drawable.vegetables,
            R.drawable.fruits,
            R.drawable.drinks,
            R.drawable.dessert

        };

            @Override
            protected void onCreate(Bundle savedInstanceState) {


        }

}

我的适配器

public class ExpandableListAdapter extends BaseExpandableListAdapter{


    @Override
    public View getChildView(int groupPosition,final int childPosition, boolean isLastChild, View convertView,
            ViewGroup parent) {

         final String childText = (String) getChild(groupPosition, childPosition);

          if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) this._context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.list_item, null);
            }
          TextView txtListChild = (TextView) convertView
                    .findViewById(R.id.lblListItem);
          txtListChild.setText(childText);

          ImageView imgListChild= (ImageView) convertView
                  .findViewById(R.id.IV_childImage);

// I could store images somehow in two dimensional array and then depending on that draw their reference id.
//          imgListChild.setImageResource();

        return convertView;
    }


    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {


         String headerTitle = (String) getGroup(groupPosition);
            if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) this._context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.list_group, null);
            }

            TextView lblListHeader = (TextView) convertView
                    .findViewById(R.id.lblListHeader);
            lblListHeader.setTypeface(null, Typeface.BOLD);
            lblListHeader.setText(headerTitle);
            ImageView imgListGroup= (ImageView) convertView
                    .findViewById(R.id.IV_group);

            imgListGroup.setImageResource(MainActivity.images[groupPosition]);

            return convertView;
    }

    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return true;
    }










}

Answer 1

在list_group 和list_item xml 文件中添加ImageView，并将图像设置为适配器类中的那些 ImageView。

就像您将文本设置为TextView，同样您可以将图像设置为ImageView

TextView txtListChild = (TextView) convertView
                    .findViewById(R.id.lblListItem);
          txtListChild.setText(childText);
ImageView imgListChild = (ImageView) convertView
                    .findViewById(R.id.image);

            imgListChild.setImageResource(R.drawable.imagename);

你的xml文件应该是

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

<CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/lblListHeader"
    android:layout_width="wrap_content"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:layout_marginLeft="8dp"
    android:drawableRight="@drawable/ic_launcher"
    android:gravity="center_horizontal"
    android:paddingLeft="32dp"
    android:paddingTop="8dp"
    android:text="Test"
    android:textSize="20sp"
    android:textAlignment="textEnd"
    android:textStyle="bold" >


</CheckedTextView> 

    <ImageView 
    android:id="@+id/IV_group"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"   
    android:contentDescription="group image"    

        />
</LinearLayout>

编辑：

图片路径\资源ID的存储方式有很多种，最简单的方式是存储在ArrayList和HashMap中。

声明一个新的 ArrayList 和 HashMap 来存储组和子项的资源 ID。

public List<Integer> groupImages;
public HashMap<Integer, List<Integer>> childImages;

将其填充到您的 prepareListData() 函数中。

groupImages= new ArrayList<Integer>();
         groupImages.add(R.drawable.vegetables);
         groupImages.add(R.drawable.fruits);
         groupImages.add(R.drawable.drinks);
         groupImages.add(R.drawable.deserts);

         childImages = new HashMap<Integer, List<Integer>>();
         List<Integer> vegetablesi = new ArrayList<Integer>();
         vegetablesi.add(R.drawable.Tomatoes);
         vegetablesi.add(R.drawable.Potatoes);
         vegetablesi.add(R.drawable.Cucumbers);
         vegetablesi.add(R.drawable.Pumpkins);
         vegetablesi.add(R.drawable.Peppers);
         vegetablesi.add(R.drawable.Onions);
         vegetablesi.add(R.drawable.Garlic);

         List<Integer> fruitsi = new ArrayList<Integer>();
         fruitsi.add(R.drawable.Strawberries);
         fruitsi.add(R.drawable.Blackcurrants);
         fruitsi.add(R.drawable.Redcurrant);
         fruitsi.add(R.drawable.Gooseberry);
         fruitsi.add(R.drawable.Kiwifruit);
         fruitsi.add(R.drawable.Grape);


         List<Integer> drinksi = new ArrayList<Integer>();
         drinksi.add(R.drawable.Vodka);
         drinksi.add(R.drawable.Milk);
         drinksi.add(R.drawable.Water);
         drinksi.add(R.drawable.CocaCola);
         drinksi.add(R.drawable.Sprite);


         List<Integer> desertsi = new ArrayList<Integer>();
         desertsi.add(R.drawable.Vodka);
         desertsi.add(R.drawable.Milk);
         desertsi.add(R.drawable.Water);
         desertsi.add(R.drawable.CocaCola);
         desertsi.add(R.drawable.Sprite);


         childImages.put(groupImages.get(0), vegetablesi);
         childImages.put(groupImages.get(1), fruitsi);
         childImages.put(groupImages.get(2), drinksi);
         childImages.put(groupImages.get(3), desertsi);

在getGroupView 和getChildView 函数中，您可以通过这种方式访问​​这些图像：

@Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
         String headerTitle = (String) getGroup(groupPosition);
            if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) this._context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.list_group, null);
            }

            TextView lblListHeader = (TextView) convertView
                    .findViewById(R.id.lblListHeader);
            lblListHeader.setTypeface(null, Typeface.BOLD);
            lblListHeader.setText(headerTitle);

            ImageView imageView = (ImageView) convertView.findViewById(R.id.IV_group);
            int imageId = this.groupImages.get(groupPosition);
            imageView.setImageResource(imageId);

            return convertView;
    }





@Override
    public View getChildView(int groupPosition,final int childPosition, boolean isLastChild, View convertView,
            ViewGroup parent) {

         final String childText = (String) getChild(groupPosition, childPosition);

          if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) this._context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.list_item, null);
            }
          TextView txtListChild = (TextView) convertView
                    .findViewById(R.id.lblListItem);
          txtListChild.setText(childText);

          ImageView imageView = (ImageView) convertView.findViewById(R.id.IV_child);
          int imageId = this.childImages.get(this.groupImages.get(groupPosition)).get(childPosition);
          imageView.setImageResource(imageId);

        return convertView;
    }

Answer 2

在 getChildView 方法中，您可以通过方法的签名识别实际的子列表项 - 变量 childPosition 和 groupPosition。

然后您可以使用开关结构来加载相关图像。