android换肤功能 如何动态获取控件中背景图片的资源id?

 //先获取本地资源引用名称，type name是R.drawable.background中的"drawable"，entry name是"background"
 String resTypeName = getContext().getResources().getResourceTypeName(id);
 String resEntryName = getContext().getResources().getResourceEntryName(id);
 //然后创建皮肤包所在应用的Context
 Context apk = getContext().createPackageContext(packageName,
   Context.CONTEXT_IGNORE_SECURITY)
 //然后就是获取皮肤包中的资源id了
 int drawavleId = apk.getResources().getIdentifier(resEntryName, resTypeName,
   apk.getPackageName()); 

 private List<Integer> skinViewList = new ArrayList<Integer> (); private void scanViewGroup(ViewGroup group, List<Integer> skinViewList, Resources res) {
  //first we need check if this ViewGroup have a background
  if(group.getId() != View.NO_ID
    && res.getResourceEntryName(group.getId()).contains(SKIN_PATTERN)
    && !skinViewList.contains(group)) {
   skinViewList.add(group.getId());
  }

  //second check its child view
  View child;

  for(int i = 0; i < group.getChildCount(); i++) {
   child = group.getChildAt(i);

   if(child instanceof ViewGroup) {
    scanViewGroup((ViewGroup)child, skinViewList, res);
   } else if(child.getId() == View.NO_ID) {
    return;
   } else {
    int viewId = child.getId();
    String entryName = res.getResourceEntryName(viewId);

    Log("scanViewGroup(), entryName of this childView : " + entryName);

    if(entryName.contains(SKIN_PATTERN) && !skinViewList.contains(child))
     skinViewList.add(child.getId());
   }
  }
 }

  //先判断前面扫描的skinViewList是否为空，不为空意味着有控件需要换肤
  if(skinViewList != null && skinViewList.size() > 0) {
   int viewId = -1, backgroundId = -1;
   for(int i = 0; i < attrs.getAttributeCount(); i++) {
    if(attrs.getAttributeName(i).equals("id")) {
     viewId = attrs.getAttributeResourceValue(i, -1);
    }

    if(attrs.getAttributeName(i).equals("background")) {
     backgroundId = attrs.getAttributeResourceValue(i, -1);
    }
   }

   //check if background drawable need save
   if(viewId != -1 && backgroundId != -1 &&
     drawableIdList != null && !drawableIdList.containsKey(viewId)) {
    drawableIdList.put(viewId, backgroundId);

    Log("add to drawableIdList, viewId = " + viewId
      + ", backgroundId = " + backgroundId);
   }
  }