将数据加载到 ExpandableListView

Load data into an ExpandableListView

我正在寻找一种将数据加载到 Expandale 列表视图的方法,我希望输出类似于所附图片中的一个 here 为了动态地完成这项工作,从 csv 中读取是否更好?还是创建数据库?此外,在子项目按下时,我希望出现 ScrollView。

到目前为止的代码如下: activity的布局:

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

    <ExpandableListView
        android:id= "@+id/android:list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

        <TextView
            android:id="@+id/android:empty"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            />
</LinearLayout>

The itemlayout:

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

    <TextView android:id="@+id/grp_child"
        android:paddingLeft="50dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

和子项目:

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

    <TextView android:id="@+id/row_name"
        android:paddingLeft="50dp"
        android:focusable="false"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

在 activity 中,到目前为止,我已经使用我遇到的一些教程对一些值进行了硬编码:

 public void onCreate(Bundle savedInstanceState) {
        try{
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_photographers);

            SimpleExpandableListAdapter expListAdapter =
                    new SimpleExpandableListAdapter(
                            this,
                            createGroupList(),             
                            R.layout.group_row,             
                            new String[] { "Group Item" },  
                            new int[] { R.id.row_name },    
                            createChildList(),              
                            R.layout.child_row,             
                            new String[] {"Sub Item"},      
                            new int[] { R.id.grp_child}     
                    );
            setListAdapter( expListAdapter );
        }catch(Exception e){
            System.out.println("Errrr +++ " + e.getMessage());
        }
    }

    /* Creating the Hashmap for the row */

    @SuppressWarnings("unchecked")
    private List createGroupList() {
        ArrayList result = new ArrayList();
        for( int i = 0 ; i < 15 ; ++i ) { // 15 groups........
            HashMap m = new HashMap();
            m.put( "Group Item","Group Item " + i ); // the key and it's value.
            result.add( m );
        }
        return (List)result;
    }

    @SuppressWarnings("unchecked")
    private List createChildList() {
        ArrayList result = new ArrayList();
        for( int i = 0 ; i < 15 ; ++i ) { // this -15 is the number of groups(Here it's fifteen)
          /* each group need each HashMap-Here for each group we have 3 subgroups */
            ArrayList secList = new ArrayList();
            for( int n = 0 ; n < 3 ; n++ ) {
                HashMap child = new HashMap();
                child.put( "Sub Item", "Sub Item " + n );
                secList.add( child );
            }
            result.add( secList );
        }
        return result;
    }


    public void  onContentChanged  () {
        System.out.println("onContentChanged");
        super.onContentChanged();
    }

    /* This function is called on each child click */
    public boolean onChildClick( ExpandableListView parent, View v, int groupPosition,int childPosition,long id) {
        System.out.println("Inside onChildClick at groupPosition = " + groupPosition +" Child clicked at position " + childPosition);
        return true;
    }


    /* This function is called on expansion of the group */
    public void  onGroupExpand  (int groupPosition) {
        try{
            System.out.println("Group expanding Listener => groupPosition = " + groupPosition);
        }catch(Exception e){
            System.out.println(" groupPosition Errrr +++ " + e.getMessage());
        }
    }

我想知道将我想要显示的数据存储在单独的 csv 文件中是否是个好主意(一个存储项目的数据,一个存储子项目的数据。一个存储 ScrollView 中的额外信息),使用 id-s 进行识别并使用 OpenCSVReader 直接从 CSV 中读取?

如果有任何建议,我将不胜感激, 谢谢

为您的可扩展列表视图创建适配器。像那样

public class ExpandableAdapter extends BaseExpandableListAdapter {
    private final Context context;
    private final List<Menu> parentObjects;

    public ExpandableAdapter(Context context, ArrayList<Menu> parentObjects) {
        this.context = context;
        this.parentObjects = parentObjects;

    }

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

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

    @Override
    public Menu getGroup(int i) {
        return parentObjects.get(i);
    }

    @Override
    public Menu.ChildMenu getChild(int i, int i2) {
        return parentObjects.get(i).childMenu.get(i2);
    }

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

    @Override
    public long getChildId(int i, int i2) {
        return 0;
    }

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

    @Override
    public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
        Menu currentParent = parentObjects.get(i);
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context
                    .LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.navdrawer_parent_item, viewGroup,false);
        }

        ImageView imageViewIndicator = (ImageView) view.findViewById(R.id.imageViewNav);
        if (getChildrenCount(i) == 0)
            imageViewIndicator.setVisibility(View.GONE);
        else
            imageViewIndicator.setVisibility(View.VISIBLE);

        TextView textViewNavMenuName = (TextView) view.findViewById(R.id.textViewNavParentMenuName);
        ImageView imageViewIcon = (ImageView) view.findViewById(R.id.imageViewIcon);
        String base64 = currentParent.getImage();
        if (base64 != null && !base64.equals("")) {
            byte[] imageAsBytes = Base64.decode(currentParent.getImage().getBytes(), Base64
                    .DEFAULT);
            imageViewIcon.setImageBitmap(BitmapFactory.decodeByteArray(imageAsBytes, 0,
                    imageAsBytes.length));

        } else
            imageViewIcon.setImageResource(R.drawable.ic_action_android);

        textViewNavMenuName.setText(currentParent.getMenuName());
        return view;
    }



    @Override
    public View getChildView(int groupPosition, int childPosition, boolean b, View view,
                             ViewGroup viewGroup) {
        Menu currentChild = getGroup(groupPosition);
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context
                    .LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.navdrawer_child_item, viewGroup,false);
        }
        View divider = view.findViewById(R.id.divider);
        if (b)
            divider.setVisibility(View.VISIBLE);
        else
            divider.setVisibility(View.GONE);

        TextView textViewNavMenuName = (TextView) view.findViewById(R.id.textViewNavChildMenuName);
        textViewNavMenuName.setText(currentChild.childMenu.get(childPosition).getMenuName());

        return view;
    }

    @Override
    public boolean isChildSelectable(int i, int i2) {
        return true;
    }
}

和可扩展列表视图的模型,如

public class Menu {
    private int AssociatedApp;
    private String MenuName;
    private String NavigateURL;
    private String ActivityName;
    private String Image;
    private int MenuID;
    public ArrayList<ChildMenu> childMenu;

    public ArrayList<ChildMenu> getChildMenu() {
        return childMenu;
    }

    public void setChildMenu(ArrayList<ChildMenu> childMenu) {
        this.childMenu = childMenu;
    }

    public int getAssociatedApp() {
        return AssociatedApp;
    }

    public void setAssociatedApp(int associatedApp) {
        AssociatedApp = associatedApp;
    }

    public String getMenuName() {
        return MenuName;
    }

    public void setMenuName(String menuName) {
        MenuName = menuName;
    }

    public String getNavigateURL() {
        return NavigateURL;
    }

    public void setNavigateURL(String navigateURL) {
        NavigateURL = navigateURL;
    }

    public String getActivityName() {
        return ActivityName;
    }

    public void setActivityName(String activityName) {
        ActivityName = activityName;
    }

    public String getImage() {
        return Image;
    }

    public void setImage(String image) {
        Image = image;
    }


    public Menu() {
    }

    public int getMenuID() {
        return MenuID;
    }

    public class ChildMenu {
        private int AssociatedApp;
        private String MenuName;
        private String NavigateURL;
        private String ActivityName;
        private String Image;
        private int MenuID;
        public ChildMenu(String menuName, String activityName) {
            this.MenuName = menuName;
            this.ActivityName=activityName;
        }
        public ChildMenu() {

        }
        public int getAssociatedApp() {
            return AssociatedApp;
        }

        public void setAssociatedApp(int associatedApp) {
            AssociatedApp = associatedApp;
        }

        public String getMenuName() {
            return MenuName;
        }

        public void setMenuName(String menuName) {
            MenuName = menuName;
        }

        public String getNavigateURL() {
            return NavigateURL;
        }

        public void setNavigateURL(String navigateURL) {
            NavigateURL = navigateURL;
        }

        public String getActivityName() {
            return ActivityName;
        }

        public void setActivityName(String activityName) {
            ActivityName = activityName;
        }

        public String getImage() {
            return Image;
        }

        public void setImage(String image) {
            Image = image;
        }

        public int getMenuID() {
            return MenuID;
        }
    }

}

好的,现在您可以使用数据创建菜单并绑定可扩展列表视图

 elv = (ExpandableListView)findViewById(R.id.elv);
        elv.setOnGroupExpandListener(onGroupExpandListenser);
        MyExpandableAdapter adapter = new MyExpandableAdapter(this, getData());//where getData() will return list of data.
        elv.setAdapter(adapter);

parent xml

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

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:paddingBottom="12dp"
        android:paddingLeft="12dp"
        android:paddingTop="12dp">

        <ImageView
            android:contentDescription="@string/app_name"

            android:id="@+id/imageViewIcon"
            android:layout_width="35dp"
            android:layout_height="35dp"
            android:layout_alignParentLeft="true"
            android:layout_margin="4dp"
           />

        <TextView
            android:id="@+id/textViewNavParentMenuName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:layout_centerVertical="true"
            android:layout_toLeftOf="@+id/imageViewNav"
            android:layout_toRightOf="@+id/imageViewIcon"
            android:padding="10dp"
            android:textSize="15sp"/>

        <ImageView
            android:contentDescription="@string/app_name"
            android:id="@+id/imageViewNav"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_margin="4dp"
            android:src="@drawable/ic_action_more_nav"
            />
    </RelativeLayout>

    <include
        layout="@layout/divider"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

child xml

<?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="wrap_content"
              android:gravity="center_vertical"

              android:orientation="vertical">

    <TextView
        android:id="@+id/textViewNavChildMenuName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="45dp"
        android:gravity="center_vertical"
        android:text="TextView"
        android:padding="16dp"/>

    <include
        layout="@layout/divider"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

像这样为可扩展列表视图添加侦听器。 groupExpandlistener 用于在打开一个时折叠其他组

private int lastExpandedPosition = -1;

用于设置侦听器

 elv.setOnChildClickListener(new DrawerItemClickListener());
        elv.setOnGroupClickListener(new DrawerItemClickListener());
        elv.setOnGroupExpandListener(new DrawerItemClickListener());

    private class DrawerItemClickListener implements ExpandableListView.OnChildClickListener,
        ExpandableListView.OnGroupClickListener, ExpandableListView.OnGroupExpandListener {
    @Override
    public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int
            childPosition, long id) {
        selectItem(childPosition, navigationConfig.getBaseExpandableListAdapter
                ().getChild
                (groupPosition, childPosition));
        return true;
    }

    @Override
    public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {

        selectItem(groupPosition, navigationConfig.getBaseExpandableListAdapter
                ().getGroup
                (groupPosition));
        return false;
    }

    @Override
    public void onGroupExpand(int groupPosition) {
        if (lastExpandedPosition != -1
                && groupPosition != lastExpandedPosition) {
            expandableListView.collapseGroup(lastExpandedPosition);
        }
        lastExpandedPosition = groupPosition;
    }
}

示例数据用于绑定 getData()。注意在 getData()

中给定的模型 class 中创建构造函数
//Sample data for expandable list view.
    public List<Menu> getData()
    {
        List<Menu> parentObjects = new ArrayList<Menu>();
        for (int i = 0; i<20; i++)
        {
            parentObjects.add(new Menu("Mother " +i, "Father " +i, "Header " + i, "Footer " +i, getChildren(i)));

        }
        return parentObjects;
    }

    private List<Menu.ChildMenu> getChildren(int childCount)
    {
        List<Menu.ChildMenu> childObjects = new ArrayList<Menu.ChildMenu>();
        for (int i =0; i<childCount; i++)
        {
            childObjects.add(new Menu.ChildMenu("Child " + (i+1), 10 +i ));
        }
        return childObjects;
    }