android - 当我们在 android 的可扩展 ListView 中打开特定组时，GroupText 发生了变化

Question

我有一个问题，当我们点击特定组打开时，我的组文本会自动更改。我找不到这个问题的根源。请向我建议有关相同的任何解决方案。

打开后:

代码(扩展适配器):

public class ExpResearchListAdapter extends BaseExpandableListAdapter {
    // Sample data set. children[i] contains the children (String[]) for
    // groups[i].
    Context context;
    private String[] groups = { "Research by Brand", "Research by Category",
        "Research by Price" , "Research by Fuel Economy", "Recently Viewed"};
    GridView label;
    TextView groupText;
    String group;
    ImageView groupImg;
    //ArrayList<String> groups = new ArrayList<String>();
    ArrayList<Integer> groupImage = new ArrayList<Integer>();
    ArrayList<Integer> childElement = new ArrayList<Integer>();
    private Integer[][] children = { 
            { R.drawable.icon_1, R.drawable.icon_2, R.drawable.icon_3, R.drawable.icon_4, R.drawable.icon_5, R.drawable.icon_6, R.drawable.icon_7, R.drawable.icon_8, R.drawable.icon_9,
                R.drawable.icon_10, R.drawable.icon_11, R.drawable.icon_12, R.drawable.icon_13, R.drawable.icon_14, R.drawable.icon_15, R.drawable.icon_16, R.drawable.icon_17, R.drawable.icon_18,
                R.drawable.icon_19, R.drawable.icon_20, R.drawable.icon_21, R.drawable.icon_22, R.drawable.icon_23, R.drawable.icon_24, R.drawable.icon_25, R.drawable.icon_26, R.drawable.icon_27,
                R.drawable.icon_28, R.drawable.icon_29, R.drawable.icon_30, R.drawable.icon_31, R.drawable.icon_32, R.drawable.icon_33, R.drawable.icon_34, R.drawable.icon_35, R.drawable.icon_36,
                R.drawable.icon_37, R.drawable.icon_38, R.drawable.icon_39, R.drawable.icon_40, R.drawable.icon_41, R.drawable.icon_42, R.drawable.icon_43, R.drawable.icon_44, R.drawable.icon_45,
                R.drawable.icon_46} 
            };
    LinearLayout linear;

    public ExpResearchListAdapter(Context context, ArrayList<String> groups, ArrayList<Integer> groupImage, ArrayList<Integer> childElement, LinearLayout linear)
    {
        this.context=context;
        //this.groups = groups;
        this.groupImage = groupImage;
        this.childElement = childElement;
        this.linear = linear;
    }

    public Object getChild(int groupPosition, int childPosition) {
        return children[groupPosition][childPosition];
    }

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

    public int getChildrenCount(int groupPosition) {
        int i = 0;
        try {
        i = children[groupPosition].length;

        } catch (Exception e) {
        }

        return 1;
    }



    public View getChildView(int groupPosition, int childPosition,
        boolean isLastChild, View convertView, ViewGroup parent) {
        if(convertView==null)
        {
            LayoutInflater inflater = LayoutInflater.from(context);
            convertView = (View) inflater.inflate(R.layout.brand_research_grid, null);
            label = (GridView) convertView.findViewById(R.id.gv_ResearchList_Child);
            label.setAdapter(new GridAdapter(context, childElement));
            label.setCacheColorHint(Color.WHITE);

            // initialize the following variables (i've done it based on your layout
            // note: rowHeightDp is based on my grid_cell.xml, that is the height i've
            //    assigned to the items in the grid.
            //final int spacingDp = 20;
            final int colWidthDp = 50;
            final int rowHeightDp = (childElement.size()/3)*10;
            //final int rowHeightDp = 107;

            // convert the dp values to pixels
            //final float COL_WIDTH = context.getResources().getDisplayMetrics().density * colWidthDp;
            final float COL_WIDTH = 10;
            //final float ROW_HEIGHT = context.getResources().getDisplayMetrics().density * rowHeightDp;
            final float ROW_HEIGHT = 107f;
            final float SPACING = context.getResources().getDisplayMetrics().density * 0;
            System.out.println("===================================RowHeight"+ROW_HEIGHT);
            System.out.println("===================================RowHeightDP"+rowHeightDp);


            // calculate the column and row counts based on your display
            final int colCount = (int)Math.floor((linear.getWidth() - (2 * SPACING)) / (COL_WIDTH + SPACING));
            final int rowCount = (int)Math.ceil((childElement.size() + 0d) / 3);
            //final int rowCount = 16;

            // calculate the height for the current grid
            final int GRID_HEIGHT = Math.round(rowCount * (ROW_HEIGHT + SPACING));
            System.out.println("===================================GHieght"+GRID_HEIGHT);
            System.out.println("===================================colCount"+colCount);
            System.out.println("===================================rowCount"+rowCount);
            // set the height of the current grid
            label.getLayoutParams().height = GRID_HEIGHT;
        }





        return convertView;
    }

    public Object getGroup(int groupPosition) {
        //return groups.get(groupPosition);
        return groups[groupPosition];
    }

    public int getGroupCount() {
        return groups.length;
    }

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

    public View getGroupView(int groupPosition, boolean isExpanded,
        View convertView, ViewGroup parent) {

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(
                    R.layout.research_list_exp_group, null);
            groupText = (TextView) convertView
                    .findViewById(R.id.tv_ResearchList_ExpParentElement);
            groupImg = (ImageView) convertView
                    .findViewById(R.id.img_ResearchList_GroupParentImage);
            group = (String) getGroup(groupPosition);
            // convertView.setClickable(false);
            groupText.setText(groups[groupPosition]);
            groupImg.setImageResource(groupImage.get(groupPosition));
        }


        return convertView;
    }

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

    public boolean hasStableIds() {
        return true;
    }

    }

提前致谢。

Answer 1

问题出在getGroupView() 函数，您错误地使用了convertView。如果 convertView 为 null，则您正在正确地展开布局并填充 View 。但是，如果它不为空，则您不会更改 View !该 View 是一个循环 View - 它是以前的组项目 View 之一，但您不知道是哪一个!你也必须填写它。当您点击组项目时，内容会被重新绘制，所有 View 可能会被回收。

您在 getChildView() 函数中遇到了同样的问题。

检查 this教程，尤其是示例 9.5。它展示了如何正确使用回收 View (以及如何使用 holder 模式)。

请注意，您的代码中还有另一个问题 - 您正试图在 ListView (ExpandableListView) 中使用 GridView。不要那样做!不要使用两个能够在另一个内部滚动的小部件。除非每个 ScrollView 使用不同的轴进行滚动，否则不要这样做。