ExpandableListView实现商品列表折叠

简介

在日常的开发中，有可能会遇到需要一些可以展开的列表，比如QQ的好友列表，电商的购物车折叠显示。Android也给我们提供ExpandableListView类，完美实现这样类似的需求, 极大的方便了我们开发。结合之前的项目我们做一个简单的讲解。
首先懒看一下最终的实现效果：

使用到的第三方框架：
AndroidAutoLayout 屏幕适配框架

代码

首先是布局需要用一个ExpandableListView，配合adapter就能实现上面额效果，直接上代码。
activity_main.xml

<com.zhy.autolayout.AutoLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical">

  <android.support.design.widget.AppBarLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:layout_width="match_parent"
      android:layout_height="wrap_content">

      <com.zhy.autolayout.AutoLinearLayout
          android:id="@+id/ll_title_root"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:background="#ec0f38"
          android:orientation="vertical">

          <com.zhy.autolayout.AutoFrameLayout
              android:layout_width="match_parent"
              android:layout_height="88px">

              <TextView
                  android:id="@+id/tv_title"
                  android:layout_width="wrap_content"
                  android:layout_height="fill_parent"
                  android:layout_gravity="center"
                  android:gravity="center"
                  android:text="优惠套餐"
                  android:textColor="#ffffff"
                  android:textSize="32px" />

              <com.zhy.autolayout.AutoLinearLayout
                  android:id="@+id/ll_back"
                  android:layout_width="100px"
                  android:layout_height="match_parent"
                  android:clickable="true"
                  android:gravity="center">

                  <ImageView
                      android:id="@+id/iv_back"
                      android:layout_width="44px"
                      android:layout_height="44px"
                      android:layout_gravity="center_vertical"
                      android:src="@mipmap/icon_back" />
              </com.zhy.autolayout.AutoLinearLayout>
          </com.zhy.autolayout.AutoFrameLayout>
      </com.zhy.autolayout.AutoLinearLayout>
  </android.support.design.widget.AppBarLayout>

  <ExpandableListView
      android:id="@+id/elv_collocation"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:background="#eeeff3"
      android:divider="#eeeff3"
      android:dividerHeight="0dp"
      android:groupIndicator="@null"
      android:listSelector="@null" />
</com.zhy.autolayout.AutoLinearLayout>

MainActivity.java
默认展开第一个，collocation.expandGroup(0);当然更好的写法是将数据写到Controller中。

public class MainActivity extends AppCompatActivity {
private ExpandableListView elv_collocation;
private List<CollocationPackageBean> collocationList;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      elv_collocation = (ExpandableListView) findViewById(R.id.elv_collocation);
      initData();
  }

private void initData() {
      collocationList = new ArrayList<>();
      CollocationPackageBean collocation_1 = new CollocationPackageBean();
      CollocationPackageBean collocation_2 = new CollocationPackageBean();

      collocation_1.setTotalPrice(new BigDecimal(897));
      collocation_1.setDiscountFee(new BigDecimal(20));
      collocation_1.setName("818国货套餐3");
      List<CollocationPackageBean.CollocationSkuBean> goodsList_1 = new ArrayList<>();
      goodsList_1.add(new CollocationPackageBean.CollocationSkuBean("Meizu/魅族 魅蓝 note3 全网通 手机 银白 16GB", "http://img11.hqbcdn.com/product/07/0a/070ac7abd57c6d9251d89547f3d62501.jpg"));
      goodsList_1.add(new CollocationPackageBean.CollocationSkuBean("VR PLUS 智能眼镜vr虚拟现实头盔 3D沉浸式 暴风魔镜 vr plus 智能头盔 白色", "http://img15.hqbcdn.com/product/c6/10/c610075082199955a8d5dcf2aa765b17.jpg"));
      collocation_1.setCollocationSkuDoList(goodsList_1);

      collocation_2.setTotalPrice(new BigDecimal(1034));
      collocation_2.setDiscountFee(new BigDecimal(26));
      collocation_2.setName("超值套餐");
      List<CollocationPackageBean.CollocationSkuBean> goodsList_2 = new ArrayList<>();
      goodsList_2.add(new CollocationPackageBean.CollocationSkuBean("Meizu/魅族 魅蓝 note3 全网通 手机 银白 16GB", "http://img11.hqbcdn.com/product/07/0a/070ac7abd57c6d9251d89547f3d62501.jpg"));
      goodsList_2.add(new CollocationPackageBean.CollocationSkuBean("Uka/优加 Meizu/魅族 魅蓝 note3全覆盖全屏钢化玻璃膜 白色", "http://img8.hqbcdn.com/product/9c/15/9c15571aa92905ea1edafb0a288f1ebb.jpg"));
      goodsList_2.add(new CollocationPackageBean.CollocationSkuBean("SanDisk/闪迪 至尊高速MicroSDHC-TF移动存储卡 Class10-48MB/S 升级版 16G", "http://img14.hqbcdn.com/product/29/cd/29cda69f5036b38454b6592f96fde774.jpg"));
      goodsList_2.add(new CollocationPackageBean.CollocationSkuBean("Huawei/华为 AM116 金属耳机 三键线控耳机 尊爵版", "http://img9.hqbcdn.com/product/0a/90/0a905d9988c91fb0625d9ee44377c8e0.jpg"));
      goodsList_2.add(new CollocationPackageBean.CollocationSkuBean("Lesimo/梵简 初见系列10000毫安充电宝 手机平板通用 移动电源 黑色", "http://img11.hqbcdn.com/product/67/3a/673ac0343758ce64e97c2d9986cbbef3.jpg"));
      collocation_2.setCollocationSkuDoList(goodsList_2);

      collocationList.add(collocation_1);
      collocationList.add(collocation_2);
      elv_collocation.setAdapter(new CollocationListAdapter(this, elv_collocation, collocationList));
      elv_collocation.expandGroup(0);
  }
}

CollocationListAdapter.java
CollocationListAdapter负责数据的填充，主要注意两个方法：getGroupView和getChildView

public class CollocationListAdapter extends BaseExpandableListAdapter {
private LayoutInflater inflater;
private Context context;
private ExpandableListView elv_collocation;
private List<CollocationPackageBean> data;

public CollocationListAdapter(Context context, ExpandableListView elv_collocation, List<CollocationPackageBean> data) {
this.context = context;
this.elv_collocation = elv_collocation;
this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.data = data;
    }

@Override
public int getGroupCount() {
return data.size();
    }

@Override
public int getChildrenCount(int groupPosition) {
return data.get(groupPosition).getCollocationSkuDoList().size();
    }

@Override
public Object getGroup(int groupPosition) {
return data.get(groupPosition);
    }

@Override
public Object getChild(int groupPosition, int childPosition) {
return data.get(groupPosition).getCollocationSkuDoList().get(childPosition);
    }

@Override
public long getGroupId(int groupPosition) {
return groupPosition;
    }

@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
    }

@Override
public boolean hasStableIds() {
return true;
    }

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;//如果子条目需要响应click事件,必需返回true
    }

@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        ParentViewHolder parentViewHolder;
if (null == convertView) {
            convertView = inflater.inflate(R.layout.collocation_list_item_parent, parent, false);
            parentViewHolder = new ParentViewHolder(convertView);
            convertView.setTag(parentViewHolder);
            AutoUtils.auto(convertView);
        } else {
            parentViewHolder = (ParentViewHolder) convertView.getTag();
        }
        CollocationPackageBean collocationPackageBean = data.get(groupPosition);
        parentViewHolder.tv_collocation_name.setText(TextUtils.isEmpty(collocationPackageBean.getName()) ? "优惠套餐" : collocationPackageBean.getName());
        parentViewHolder.tv_save_text.setText("立省￥" + collocationPackageBean.getDiscountFee());
        parentViewHolder.iv_status.setImageResource(isExpanded ? R.mipmap.icon_top : R.mipmap.icon_bottom);
        parentViewHolder.v_space.setVisibility(isExpanded ? View.GONE : View.VISIBLE);
        parentViewHolder.hsv_goods_list.setVisibility(isExpanded ? View.GONE : View.VISIBLE);
        parentViewHolder.hsv_goods_list.setFocusable(false);//设置后解决套餐无法正常展开的bug
if (!isExpanded) {
//设置套餐折叠时显示套餐商品的图片
            initGoodsImage(collocationPackageBean, parentViewHolder, groupPosition);
        }
return convertView;
    }

@Override
public View getChildView(final int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        ChildViewHolder childViewHolder;
if (null == convertView) {
            convertView = inflater.inflate(R.layout.collocation_list_item_child, parent, false);
            childViewHolder = new ChildViewHolder(convertView);
            convertView.setTag(childViewHolder);
            AutoUtils.auto(convertView);
        } else {
            childViewHolder = (ChildViewHolder) convertView.getTag();
        }
final CollocationPackageBean.CollocationSkuBean collocationSkuBean = data.get(groupPosition).getCollocationSkuDoList().get(childPosition);
        childViewHolder.sdv_goods_img.setImageURI(Uri.parse(collocationSkuBean.getImageMd5()));
        childViewHolder.tv_goods_title.setText(collocationSkuBean.getSkuTitle());
        childViewHolder.ll_root_view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//进入商品详情页操作
            }
        });
if (childPosition == data.get(groupPosition).getCollocationSkuDoList().size() - 1) {
//当前套餐的最后一个商品
            childViewHolder.ll_bottom.setVisibility(View.VISIBLE);
            childViewHolder.tv_collocation_price.setText(data.get(groupPosition).getTotalPrice().toString());
            childViewHolder.tv_add_cart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//把套餐商品加入购物车操作
                }
            });
        } else {
            childViewHolder.ll_bottom.setVisibility(View.GONE);
        }
return convertView;
    }

    class ParentViewHolder {
private View v_space;
private ImageView iv_status;
private HorizontalScrollView hsv_goods_list;
private TextView tv_collocation_name, tv_save_text;

private ParentViewHolder (View view) {
            v_space = view.findViewById(R.id.v_space);
            iv_status = (ImageView) view.findViewById(R.id.iv_status);
            hsv_goods_list = (HorizontalScrollView) view.findViewById(R.id.hsv_goods_list);
            tv_collocation_name = (TextView) view.findViewById(R.id.tv_collocation_name);
            tv_save_text = (TextView) view.findViewById(R.id.tv_save_text);
        }
    }

private class ChildViewHolder {
private SimpleDraweeView sdv_goods_img;
private LinearLayout ll_bottom, ll_root_view;
private TextView tv_add_cart, tv_goods_title, tv_collocation_price;

private ChildViewHolder (View view) {
            sdv_goods_img = (SimpleDraweeView) view.findViewById(R.id.sdv_goods_img);
            ll_bottom = (LinearLayout) view.findViewById(R.id.ll_bottom);
            ll_root_view = (LinearLayout) view.findViewById(R.id.ll_root_view);
            tv_add_cart = (TextView) view.findViewById(R.id.tv_add_cart);
            tv_goods_title = (TextView) view.findViewById(R.id.tv_goods_title);
            tv_collocation_price = (TextView) view.findViewById(R.id.tv_collocation_price);
        }
    }

/**
 * 初始化并设置套餐折叠时的所有商品图片
 * @param collocationPackageBean
 * @param parentViewHolder
 * @param groupPosition
 */
private void initGoodsImage(CollocationPackageBean collocationPackageBean,
                                ParentViewHolder parentViewHolder, final int groupPosition) {
        View collocationView;
        SimpleDraweeView sdv_cart_image;
        RelativeLayout rl_middle;
        LinearLayout rootview = new LinearLayout(context);
for (int i = 0, len = collocationPackageBean.getCollocationSkuDoList().size(); i < len; i++) {
            collocationView = inflater.inflate(R.layout.item_gift_img, null);
            sdv_cart_image = (SimpleDraweeView) collocationView.findViewById(R.id.sdv_cart_image);
            rl_middle = (RelativeLayout) collocationView.findViewById(R.id.rl_middle);
            sdv_cart_image.setImageURI(Uri.parse(collocationPackageBean.getCollocationSkuDoList().get(i).getImageMd5()));
            rl_middle.setVisibility(View.INVISIBLE);
            collocationView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//手动实现展开操作
                    elv_collocation.expandGroup(groupPosition);
                }
            });
            AutoUtils.auto(collocationView);
            rootview.addView(collocationView);
        }
        parentViewHolder.hsv_goods_list.removeAllViews();
        parentViewHolder.hsv_goods_list.addView(rootview);
    }
}

collocation_list_item_child.xml
子布局

<com.zhy.autolayout.AutoLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:fresco="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="#ffffff"
  android:clickable="true"
  android:orientation="vertical">

  <com.zhy.autolayout.AutoLinearLayout
      android:id="@+id/ll_root_view"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:background="@drawable/selector_me_bg_item"
      android:paddingBottom="28px"
      android:paddingLeft="24px"
      android:paddingRight="24px"
      android:paddingTop="30px">

      <com.facebook.drawee.view.SimpleDraweeView
          android:id="@+id/sdv_goods_img"
          android:layout_width="120px"
          android:layout_height="120px"
          android:background="@drawable/shape_cart_goods_border"
          android:padding="1dp"
          fresco:placeholderImage="@mipmap/icon_loading_bg" />

      <TextView
          android:id="@+id/tv_goods_title"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_marginLeft="20px"
          android:layout_weight="1"
          android:ellipsize="end"
          android:maxLines="2"
          android:textColor="#222222"
          android:textSize="30px" />

      <View
          android:layout_width="118px"
          android:layout_height="1px" />

      <ImageView
          android:layout_width="18px"
          android:layout_height="28px"
          android:src="@mipmap/icon_right" />
  </com.zhy.autolayout.AutoLinearLayout>

  <View
      android:layout_width="match_parent"
      android:layout_height="1px"
      android:layout_marginLeft="24px"
      android:background="#dddddd" />

  <com.zhy.autolayout.AutoLinearLayout
      android:id="@+id/ll_bottom"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical">

      <com.zhy.autolayout.AutoLinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:gravity="center_vertical"
          android:paddingLeft="24px"
          android:paddingRight="24px"
          android:paddingTop="20px">

          <TextView
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="套餐价格:"
              android:textColor="#888888"
              android:textSize="30px" />

          <TextView
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_marginLeft="20px"
              android:text="￥"
              android:textColor="#ec0f38"
              android:textSize="22px" />

          <TextView
              android:id="@+id/tv_collocation_price"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:textColor="#ec0f38"
              android:textSize="30px" />

          <View
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_weight="1" />

          <TextView
              android:id="@+id/tv_add_cart"
              android:layout_width="180px"
              android:layout_height="50px"
              android:background="@drawable/selector_add_cart_red_btn"
              android:gravity="center"
              android:text="加入购物车"
              android:textColor="@drawable/selector_add_cart_red_tv"
              android:textSize="28px" />
      </com.zhy.autolayout.AutoLinearLayout>

      <View
          android:layout_width="match_parent"
          android:layout_height="20px"
          android:layout_marginTop="20px"
          android:background="#eeeff3" />
  </com.zhy.autolayout.AutoLinearLayout>
</com.zhy.autolayout.AutoLinearLayout>

collocation_list_item_parent.xml
父布局

<com.zhy.autolayout.AutoLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="#ffffff"
  android:orientation="vertical"
  android:paddingTop="20px">

  <com.zhy.autolayout.AutoLinearLayout
      android:layout_width="match_parent"
      android:layout_height="50px"
      android:layout_marginBottom="30px"
      android:gravity="center_vertical"
      android:paddingLeft="24px"
      android:paddingRight="24px">

      <TextView
          android:id="@+id/tv_collocation_name"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textColor="#222222"
          android:textSize="30px" />

      <TextView
          android:id="@+id/tv_save_text"
          android:layout_width="wrap_content"
          android:layout_height="40px"
          android:layout_marginLeft="20px"
          android:background="@drawable/shape_save_money"
          android:gravity="center"
          android:paddingLeft="18px"
          android:paddingRight="18px"
          android:textColor="#ffffff"
          android:textSize="24px" />

      <View
          android:layout_width="0dp"
          android:layout_height="1px"
          android:layout_weight="1" />

      <ImageView
          android:id="@+id/iv_status"
          android:layout_width="28px"
          android:layout_height="18px"
          android:layout_gravity="right|center_vertical"
          android:src="@mipmap/icon_top" />
  </com.zhy.autolayout.AutoLinearLayout>

  <HorizontalScrollView
      android:id="@+id/hsv_goods_list"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:paddingLeft="24px"
      android:scrollbars="none" />

  <View
      android:id="@+id/v_space"
      android:layout_width="match_parent"
      android:layout_height="20px"
      android:layout_marginTop="20px"
      android:background="#eeeff3"
      android:visibility="gone" />
</com.zhy.autolayout.AutoLinearLayout>

这样就基本实现了。源码地址