android中的三级可扩展列表

Question

我发现了很多关于三层可扩展的问题。我试过我无法扩展它，它没有显示。

我需要在我的应用程序中保留三级可扩展列表视图。这些值取自 db。我可以实现正常的可扩展原生组件。我已经尝试了三层可扩展它不起作用。

MyExpandableListAdapter mAdapter;

    private void createExpandableListViewDialog() {

        LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        viewList = MainActivity.this.getLayoutInflater().inflate(
                R.layout.custom_dialog, null);

        setContentView(viewList);
        Display newDisplay = getWindowManager().getDefaultDisplay();
        int width = newDisplay.getWidth();
        elvForDialog = (ExpandableListView) viewList
                .findViewById(R.id.elvForDialog);

        mAdapter = new MyExpandableListAdapter(MainActivity.this, listchapt,
                null);

        elvForDialog.setIndicatorBounds(width - 20, width);// 130
        elvForDialog.setAdapter(mAdapter);

        elvForDialog.setOnGroupClickListener(new OnGroupClickListener() {

            public boolean onGroupClick(ExpandableListView arg0, View arg1,
                    int arg2, long arg3) throws RuntimeException {
                try{

                    //String pos = elvForDialog.getItemAtPosition(arg2).toString();
                    String pos = (String)mAdapter.getGroup(arg2);
                    System.out.println("position=" + pos);
                    //List<String> children = new ArrayList<String>();
                    children = new ArrayList<String>();
                    if (mAdapter.getChildrenCount(arg2) == 0) {
                        dbHelper.openDataBase();
                        children = dbHelper.GetSubchapt(pos);
                        dbHelper.close();
                        mAdapter.addChildren(arg2, children);
                    }


                    System.out.println("explist" + listSubchapt);

                    try {

                        Log.v("LH", "ssetOnGroupClickListener");
                        Log.v("LH", "" + viewListLastSelected.toString());
                        Log.v("LH",
                                "" + ((TextView) viewListLastSelected).getText());

                    } catch (Exception e) {
                        Log.v("LH", "ERROR@onCreate: " + e.toString());
                    }
                }
                catch(Exception e) {
                    System.out.println("e=" +e);

                }

                return false;
            }
        });

        elvForDialog.setOnChildClickListener(new OnChildClickListener() {

            public boolean onChildClick(ExpandableListView arg0, View arg1,
                    int arg2, int arg3, long arg4) throws RuntimeException {

                //currentChapt = listchapt.get(arg2).toString();
                //currentSubchapt = listNames.get(arg2).get(arg3).toString();
                String currentChapt = (String)mAdapter.getGroup(arg2);
                String currentSubchapt = (String)mAdapter.getChild(arg2, arg3);
                System.out.println("Yes it shows child " + currentChapt
                        + currentSubchapt);
                // createExpandableListViewDialog(1);

                Intent in = new Intent(MainActivity.this, WebContent.class);
                in.putExtra("chapterid", currentChapt);
                in.putExtra("subchaptid", currentSubchapt);
                startActivity(in);

                elvForDialog.clearChildFocus(viewListLastSelected);

                try {

                    viewListLastSelected.setBackgroundDrawable(null);
                    ((TextView) viewListLastSelected).setTextColor(Color.GRAY);
                } catch (Exception e) {
                }
                ((TextView) arg1).setTextColor(Color.WHITE);
                viewListLastSelected = arg1;

                return false;
            }
        });

        elvForDialog.setOnGroupExpandListener(new OnGroupExpandListener() {

            public void onGroupExpand(int groupPosition) {
                int len = mAdapter.getGroupCount();

                for (int i = 0; i < len; i++) {
                    if (i != groupPosition) {
                        elvForDialog.collapseGroup(i);
                    }
                }
            }

        });

MyExpandableListAdapter 类

public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    Activity activity;
    List<String> listGroup = new ArrayList<String>();
    // List<List<String>> listChild = new ArrayList<List<String>>();
    SparseArray<List<String>> listChild = new SparseArray<List<String>>();
    private int _posGroup = 0;
    private int _posChild = 0;

    public MyExpandableListAdapter(Activity a, List<String> group,
            List<List<String>> children) {
        super();
        this.activity = a;
        this.listGroup = group;
        // this.listChild = children;
    }

    public void addChildren(int groupPosition, List<String> children) {
        this.listChild.put(groupPosition, children);
    }

    public Object getChild(int groupPosition, int childPosition) {
        return listChild.get(groupPosition).get(childPosition);
    }

    public long getChildId(int groupPosition, int childPosition) {
        // Log.v("LH", "ChildID: " + childPosition);
        _posGroup = groupPosition;
        _posChild = childPosition;
        return childPosition;
    }

    public int getChildrenCount(int groupPosition) {
        if (listChild.get(groupPosition) == null) {
            Log.e("mAdapter.getChildrenCount",
                    "Tried to access children which have not yet been added");
            return 0;
        } else
            return listChild.get(groupPosition).size();

    }

    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        //String string = listChild.get(groupPosition).get(childPosition);
        //View view = getGenericChildView(string);

        /*TextView text = (TextView) view;
        if (this._posGroup == groupPosition && this._posChild == childPosition) {
            text.setTextColor(Color.rgb(85, 85, 85));
            text.setTypeface(null, Typeface.BOLD);
        }*/
        //view.setBackgroundResource(R.drawable.menu_submenubg);

         CustExpListview SecondLevelexplv = new CustExpListview(activity);

         SecondLevelexplv.setAdapter(new SecondLevelAdapter());

         SecondLevelexplv.setGroupIndicator(null);

         return SecondLevelexplv;


        //return view;

    }

    // group method stub

    public Object getGroup(int groupPosition) {
        return listGroup.get(groupPosition);
    }

    public int getGroupCount() {
        return listGroup.size();
    }

    public long getGroupId(int groupPosition) {
        // Log.v("LH", "GroupID: " + groupPosition);
        return groupPosition;
    }

    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        String string = listGroup.get(groupPosition);
        View result = getGenericGroupView(string);
        result.setBackgroundResource(R.drawable.menu_hoverbg);
        return result;
    }

    public TextView getGenericChildView(String s) {
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, 0);
        lp.height = 73; // 73,50
        TextView text = new TextView(activity);
        text.setLayoutParams(lp);
        text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        text.setPadding(50, 0, 0, 0);
        text.setTextColor(Color.rgb(85, 85, 85));
        text.setTypeface(null, Typeface.BOLD);
        text.setTextSize(15);
        text.setText(s);
        return text;
    }

    public TextView getGenericGroupView(String s) {
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, 0);
        lp.height = 60;
        TextView text = new TextView(activity);
        text.setLayoutParams(lp);
        text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        text.setPadding(20, 0, 0, 0);
        text.setTextSize(20);
        text.setTextColor(Color.WHITE);
        text.setText(s);
        return text;
    }

    public boolean hasStableIds() {
        return false;
    }

    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    public class CustExpListview extends ExpandableListView {

        int intGroupPosition, intChildPosition, intGroupid;

        public CustExpListview(Context context) {

            super(context);

        }

        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

            widthMeasureSpec = MeasureSpec.makeMeasureSpec(960,

            MeasureSpec.AT_MOST);

            heightMeasureSpec = MeasureSpec.makeMeasureSpec(600,

            MeasureSpec.AT_MOST);

            super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        }

    }

    public class SecondLevelAdapter extends BaseExpandableListAdapter {

        private int _posGroup = 0;
        private int _posChild = 0;


        public Object getChild(int groupPosition, int childPosition) {
            return listChild.get(groupPosition).get(childPosition);
        }

        public long getChildId(int groupPosition, int childPosition) {
            // Log.v("LH", "ChildID: " + childPosition);
            _posGroup = groupPosition;
            _posChild = childPosition;
            return childPosition;
        }

        public int getChildrenCount(int groupPosition) {
            if (listChild.get(groupPosition) == null) {
                Log.e("mAdapter.getChildrenCount",
                        "Tried to access children which have not yet been added");
                return 0;
            } else
                return listChild.get(groupPosition).size();

        }

        public View getChildView(int groupPosition, int childPosition,
                boolean isLastChild, View convertView, ViewGroup parent) {
            String string = listChild.get(groupPosition).get(childPosition);
            View view = getGenericChildView(string);

            TextView text = (TextView) view;
            if (this._posGroup == groupPosition
                    && this._posChild == childPosition) {
                text.setTextColor(Color.rgb(85, 85, 85));
                text.setTypeface(null, Typeface.BOLD);
            }
            view.setBackgroundResource(R.drawable.menu_submenubg);

            // return SecondLevelexplv;

            return view;
        }

        // group method stub

        public Object getGroup(int groupPosition) {
            return listChild.get(groupPosition);
        }

        public int getGroupCount() {
            return listChild.size();
        }

        public long getGroupId(int groupPosition) {
            // Log.v("LH", "GroupID: " + groupPosition);
            return groupPosition;
        }

        public View getGroupView(int groupPosition, boolean isExpanded,
                View convertView, ViewGroup parent) {
            String string = listGroup.get(groupPosition);
            View result = getGenericGroupView(string);
            result.setBackgroundResource(R.drawable.menu_hoverbg);
            return result;
        }

        public TextView getGenericChildView(String s) {
            AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.FILL_PARENT, 0);
            lp.height = 73; // 73,50
            TextView text = new TextView(activity);
            text.setLayoutParams(lp);
            text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
            text.setPadding(50, 0, 0, 0);
            text.setTextColor(Color.rgb(85, 85, 85));
            text.setTypeface(null, Typeface.BOLD);
            text.setTextSize(15);
            text.setText(s);
            return text;
        }

        public TextView getGenericGroupView(String s) {
            AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.FILL_PARENT, 0);
            lp.height = 60;
            TextView text = new TextView(activity);
            text.setLayoutParams(lp);
            text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
            text.setPadding(20, 0, 0, 0);
            text.setTextSize(20);
            text.setTextColor(Color.WHITE);
            text.setText(s);
            return text;
        }

        public boolean hasStableIds() {
            return false;
        }

        public boolean isChildSelectable(int groupPosition, int childPosition) {
            return true;
        }

    }

}

这会扩展父级项目，但是，它会生成父级的重复项目。我该如何正确地做到这一点？这是正确的方法，但我的适配器坏了，因此生成了重复的项目？

我只是找不到我在这里缺少的东西......在此先感谢。

Answer 1

你需要做的是在显示之前使用CustomExpandableListView来测量它的children和group。

尝试使用以下代码。

public class CustomExpandableListView extends ExpandableListView {
    boolean expanded = true;

    public CustomExpandableListView(Context context, AttributeSet attrs,
            int defStyle) {
        super(context, attrs, defStyle);
    }

    public CustomExpandableListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomExpandableListView(Context context) {
        super(context);
    }

    public boolean isExpanded() {
        return expanded;
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // HACK! TAKE THAT ANDROID!
        if (isExpanded()) {
            // Calculate entire height by providing a very large height hint.
            // View.MEASURED_SIZE_MASK represents the largest height possible.
            int expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK,
                    MeasureSpec.AT_MOST);
            super.onMeasure(widthMeasureSpec, expandSpec);

            ViewGroup.LayoutParams params = getLayoutParams();
            params.height = getMeasuredHeight();
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    public void setIsExpanded(boolean expanded) {
        this.expanded = expanded;
    }
}