Android expandablelistview组/父背景图片在折叠或展开时发生变化

Question

我尝试在折叠或展开时交换 expandablelistview 组背景图像。但是背景图像没有正确交换。例如，当我展开第一组时，第二组或第三组的背景会交换。

我正在使用 RelativeLayout(组布局)和 SimpleExpandableListAdapter(适配器)。这是我所做的:

// Create 2 drawable background. One for collapse and one for expand
private Drawable collapseBG, expandBG;
private ExpandableListView myView;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    collapseBG = getResources().getDrawable(R.drawable.box_bg_header_collapse);
    expandBG = getResources().getDrawable(R.drawable.box_bg_header_expand);
    myView = (ExpandableListView) findViewById(R.id.myView);
}

myView.setOnGroupCollapseListener(new ExpandableListView.OnGroupCollapseListener() {
    public void onGroupCollapse(int groupPosition_c) {
        myView.getChildAt(groupPosition_c).setBackgroundDrawable(collapseBG);
    }
});

myView.setOnGroupExpandListener (new ExpandableListView.OnGroupExpandListener() {
    public void onGroupExpand(int groupPosition_e) {
        myView.getChildAt(groupPosition_e).setBackgroundDrawable(expandBG);
    }
});

有人知道怎么做吗？

Answer 1

我认为您应该制作自己的适配器，它扩展了 SimpleExpandableListAdapter。在那个类中你应该覆盖

public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
 View result = super.getGroupView(groupPosition, isExpanded, convertView, parent);

 if (isExpanded) {
     result.setBackgroundDrawable(expandBG);
 } else {
     result.setBackgroundDrawable(collapseBG);
 }

 return result;
}

在 onCreate 函数中你应该像下面这样写:

myView.setlistAdapter (new YourExtendedSimpleExpandableListAdapter( ...... ));

希望对你有帮助