Nsryjdtyk

I hope GridView inside ExpandableLisView like this.

This is my code :

MainActivity.java:

private List<List<String>> itemList; //child's data



ExpandableListViewAdapter adapter = new ExpandableListViewAdapter(MainActivity.this, groupList, itemList);

ExpandableListViewAdapter.java:

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



    gridView = (GridView) convertView;

    MyGridViewAdapter gridViewAdapter = new MyGridViewAdapter(context, itemList.get(groupPosition));

    gridView.setAdapter(gridViewAdapter);

MyGridViewAdapter.java

List<String> itemGridList;



public View getView(int position, View convertView, ViewGroup parent) {



    if (null == convertView) {

            convertView = View.inflate(context, R.layout.gridview_item, null);

        }

    TextView item_name = (TextView) convertView.findViewById(R.id.item_name);

    ImageView item_icon = (ImageView) convertView.findViewById(R.id.item_icon);



    item_name.setText(itemGridList.get(position));

    item_icon.setImageResource(item_icon.get(position)); //get error?

}

I don't know why item_icon.setImageResource will get error ?

what I am missing?

Update :

MyGridViewAdapter.java

int imageId; //add

item_icon.setImageResource(imageId[position]);

but I get NullPointerException

I try to show imageviews in MainActivity , this is my data :

private List<List<String>> itemList;



List<String> groupList = initData();

ExpandableListViewAdapter adapter = new ExpandableListViewAdapter(MainActivity.this, groupList, itemList);

elv.setAdapter(adapter);



   private List<String> initData() {

     List<String> groupList = new ArrayList<>();

     List<String> itemGridList1 = new ArrayList<>();

     String item1 = getResources().getStringArray(R.array.sport);

     itemGridList1.add(item1[0]);

     itemGridList1.add(item1[1]);



     List<String> itemGridList2 = new ArrayList<>();

     String item2 = getResources().getStringArray(R.array.healthy);

     itemGridList2.add(item2[0]);

     itemGridList2.add(item2[1]);



     itemList = new ArrayList<>();

     itemList.add(itemGridList1);

     itemList.add(itemGridList2);

     return groupList;

    }

Update :

ExpandableListActivity.java

private int logos = new int { R.drawable.fitness, R.drawable.walking, R.drawable.temp };

private String generalsTypes = new String { "Sport", "Healthy", "Measure" };

private String generals = new String {

        {"Swimming", "Hiking", "Climbing", "Biking"},

        {"Walking" , "Running"},

        {"Measure"}

};

private int generallogos = new int{

        { R.drawable.ic_swimming, R.drawable.ic_hiking, R.drawable.ic_climbing, R.drawable.ic_bike },

        { R.drawable.ic_walk, R.drawable.ic_running },

        { R.drawable.ic_matters }

};



protected void onCreate(Bundle savedInstanceState) {

   super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);



    ExpandableListView elv = findViewById(R.id.expenview);

    elv.setAdapter(adapter);

    elv.setGroupIndicator(null);

}



ExpandableListAdapter adapter = new BaseExpandableListAdapter() {

   @Override

    public int getGroupCount() {

        return generalsTypes.length;

    }



    @Override

    public int getChildrenCount(int groupPosition) {

        return generals[groupPosition].length;

    }



    @Override

    public Object getGroup(int groupPosition) {

        return generalsTypes[groupPosition];

    }



    @Override

    public Object getChild(int groupPosition, int childPosition) {

        return generals[groupPosition][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 View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

        LinearLayout ll = new LinearLayout(

                ExpandableListActivity.this);

        ImageView logo = new ImageView(ExpandableListActivity.this);

        logo.setImageResource(logos[groupPosition]);

        logo.setPadding(50, 0, 0, 0);

        ll.addView(logo);

        TextView textView = getTextView();

        textView.setTextColor(Color.BLACK);

        textView.setText(getGroup(groupPosition).toString());

        ll.addView(textView);

        return ll;

    }



     @Override

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

        LinearLayout ll = new LinearLayout(

                ExpandableListActivity.this);

        ImageView generallogo = new ImageView(

                ExpandableListActivity.this);

        generallogo

                .setImageResource(generallogos[groupPosition][childPosition]);

        ll.addView(generallogo);

        TextView textView = getTextView();

        textView.setText(getChild(groupPosition, childPosition)

                .toString());

        ll.addView(textView);

        return ll;

    }



   @Override

    public boolean isChildSelectable(int groupPosition, int childPosition) {

        return true;

    }

};

I hope like this :
GridView with ImageView

item_icon is an ImageView Object and it is given integer value which is located in R.java file.

I thing you are doing mistake to get integer resource for Image to be shown in ImageView Try with below code.

item_icon.setImageResource(--put here some actual resources--); 

   private List<String> Group;

   private List<List<String>> Child;

   private List<String> Child_1;

   private List<String> Child_2;

   private List<String> Child_3;

   private List<List<Integer>> ChildPicture;



   @Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);



    Group = new ArrayList<String>();

    Group.add("SPORT");

    Group.add("Healthy");

    Group.add("Measure");



    Child_1 = new ArrayList<String>();

    Child_1.add("Swimming");

    Child_1.add("Biking");

    Child_1.add("Hiking");



    Child_2 = new ArrayList<String>();

    Child_2.add("Walking");

    Child_2.add("Running");



    Child_3 =new ArrayList<String>();

    Child_3.add("Measure");



    Child = new ArrayList<List<String>>();

    Child.add(Child_1);

    Child.add(Child_2);

    Child.add(Child_3);



    List<Integer> ChildPic_1 = new ArrayList<Integer>();

    ChildPic_1.add(R.drawable.ic_swimming);

    ChildPic_1.add(R.drawable.ic_bike);

    ChildPic_1.add(R.drawable.ic_hiking);



    List<Integer> ChildPic_2 = new ArrayList<Integer>();

    ChildPic_2.add(R.drawable.ic_walk);

    ChildPic_2.add(R.drawable.ic_running);



    List<Integer> ChildPic_3 = new ArrayList<Integer>();

    ChildPic_3.add(R.drawable.ic_matters);



    ChildPicture = new ArrayList<List<Integer>>();

    ChildPicture.add(ChildPic_1);

    ChildPicture.add(ChildPic_2);

    ChildPicture.add(ChildPic_3);



    ExpandableListView elv = findViewById(R.id.expenview);

    elv.setAdapter(new MyExpandableAdapter(Main2Activity.this));

    elv.setGroupIndicator(null);

}

the reasult is :ExpandableListView child with imageView and TextView

but I still find out that child is gridView or gridLayout ....

item_icon is not a list Right? So how can you get the position from item_icon?

you have

List<String> itemGridList;

as the list that you are passing to the item_name

Similarly you should have a list for the images to be shown