ExpandableListView

ExpandableListView

1.界面

• Item_Group_layout 就一个TextView

<?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">
<TextView
    android:id="@+id/expandable_listView_item_group_tv"
    android:text="123"
    android:textSize="20dp"
    android:gravity="center"
    android:layout_margin="3dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>
</LinearLayout>

• Item 布局， 一个ImageView 和一个TextView

  <?xml version="1.0" encoding="utf-8"?>
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:orientation="horizontal"
                android:layout_width="match_parent"
                android:layout_height="match_parent">
  <ImageView
      android:id="@+id/expandable_listView_item_group_iv"
      android:background="@drawable/img2"
      android:layout_margin="10dp"
      android:layout_width="40dp"
      android:layout_height="40dp"/>
      <TextView
          android:id="@+id/expandable_listView_item_tv"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_marginTop="20dp"
          android:text="Group 1  Item 1"
          android:textSize="24dp"/>
  </LinearLayout>

2. 初始化数据，设置Adapter

    private ArrayList<String> groupData;//存储Group 信息
    ArrayList<ArrayList<Item>> allItems; //以Group 为单位，存储Items
    ArrayList<Item> items; //每个组

		//初始化组信息
        groupData=new ArrayList<>();
        groupData.add("Group1");
        groupData.add("Group2");
        groupData.add("Group3");

        allItems=new ArrayList<>();

        //Group1
        items =new ArrayList<>();
        items.add(new Item("I am the group 1 Item1",R.drawable.img1));
        items.add(new Item("I am the group 1 Item2",R.drawable.img1));
        items.add(new Item("I am the group 1 Item3",R.drawable.img1));
        allItems.add(items); //将每组数据添加到总集合当中

        //Group2
        items=new ArrayList<>();
        items.add(new Item("I am the group 2 Item1",R.drawable.img2));
        items.add(new Item("I am the group 2 Item2",R.drawable.img2));
        items.add(new Item("I am the group 2 Item3",R.drawable.img2));
        allItems.add(items);

        //Group3
        items=new ArrayList<>();
        items.add(new Item("I am the group 3 Item1",R.drawable.img3));
        items.add(new Item("I am the group 3 Item2",R.drawable.img3));
        items.add(new Item("I am the group 3 Item3",R.drawable.img3));
        allItems.add(items);

        listView=(ExpandableListView)findViewById(R.id.expandableList_lv);
        //为ListView设置adapter
        MyBaseExpandableAdapter adapter=new MyBaseExpandableAdapter(this,groupData,allItems);
        listView.setAdapter(adapter);

        //为列表设置点击事件
        listView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {

                Toast.makeText(ExpandableListViewActivity.this, "你点击了：" +
                        allItems.get(groupPosition).get(childPosition).getText(),Toast.LENGTH_SHORT).show();
                return true;
            }
        });

3、MyBaseExpandableAdapter：

BaseExpandableListAdapter 与 BaseAdapter不同是 getGroupView和 getChildView

需要重写 isChildSelectable，要不然不会触发 子Item的点击事件。

class MyBaseExpandableAdapter extends BaseExpandableListAdapter{

    private ArrayList<String> groupData;
    private ArrayList<ArrayList<Item>> itemData;
    private Context mContext;

    public MyBaseExpandableAdapter(Context context, ArrayList<String> groupData,ArrayList<ArrayList<Item>> itemData) {
        this.mContext=context;
        this.groupData=groupData;
        this.itemData=itemData;
    }

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

    @Override
    public int getChildrenCount(int i) {
        return itemData.get(i).size();
    }

    @Override
    public Object getGroup(int i) {
        return groupData.get(i);
    }

    @Override
    public Object getChild(int i, int i1) {
        return itemData.get(i).get(i1);
    }

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

    @Override
    public long getChildId(int i, int i1) {
        return i1;
    }

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

  //获取显示分组的视图
    @Override
    public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
        ViewHolderGroup viewHolderGroup;
        if(view==null){
            view=View.inflate(mContext,R.layout.expandableview_group_layout,null);
            viewHolderGroup=new ViewHolderGroup();
            viewHolderGroup.tv_group_name=(TextView)view.findViewById(R.id.expandable_listView_item_group_tv);
            view.setTag(viewHolderGroup);
        }else{
            viewHolderGroup=(ViewHolderGroup)view.getTag();
        }

        viewHolderGroup.tv_group_name.setText(groupData.get(i));
        return view;
    }

  //获取Item视图
    @Override
    public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {
        ViewHolderItem viewHolderItem;
        if(view==null){
            view=View.inflate(mContext,R.layout.expandablelistview_item_layout,null);
            viewHolderItem=new ViewHolderItem();
            viewHolderItem.tv_name=(TextView)view.findViewById(R.id.expandable_listView_item_tv);
            viewHolderItem.img_icon=(ImageView)view.findViewById(R.id.expandable_listView_item_group_iv);
            view.setTag(viewHolderItem);
        }else {
            viewHolderItem=(ViewHolderItem)view.getTag();
        }

        viewHolderItem.tv_name.setText(itemData.get(i).get(i1).getText());
        viewHolderItem.img_icon.setImageResource(itemData.get(i).get(i1).getImageId());
        return view;
    }

    //  设置子列表是否可以选中
    @Override
    public boolean isChildSelectable(int i, int i1) {
        return true;
    }

    private  class ViewHolderGroup{
        private TextView tv_group_name;
    }

    private  class ViewHolderItem{
        private ImageView img_icon;
        private TextView tv_name;
    }

Java Been：

class Item{
    private String text;
    private int imageId;

    public Item(String text, int imageId) {
        this.text = text;
        this.imageId = imageId;
    }

    public int getImageId() {
        return imageId;
    }

    public void setImageId(int imageId) {
        this.imageId = imageId;
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }
}