privatevoidchangeOrderOnce(){// 拿到数据List<Idiom> idiomList = idiomModel.getIdiomList()// 第一次进入时打乱成语顺序if(PreferenceUtil.getString("order","").equals("")){// 获取自然顺序的数字数组List<String> a =newArrayList<>();for(int i =0; i < idiomList.size(); i++){a.add(""+ i);}// 打乱Collections.shuffle(a);//打乱后以“-”分隔开每个数据并保存到数据库String b ="";for(int i =0; i < a.size(); i++){b = b + a.get(i)+"-";}PreferenceUtil.put("order", b);}// 拿到打乱后的数字数组String[] c = PreferenceUtil.getString("order","").split("-");// 新建一个List,以打乱后的数字数组为顺序将原数据添加进去List<Idiom> newIdiomList =newArrayList<>();for(int i =0; i < idiomList.size(); i++){newIdiomList.add(idiomList.get(Integer.parseInt(c[i])));}idiomModel.setIdiomList(newIdiomList);}