2018.11.3

btn_for_index.setOnClickListener {
            var desc = ""
            for(i in goodsMutList.indices){
                val item = goodsMutList[i]
                desc = "${desc}name: ${item}\n"
            }
            tv_list_result.text = "lamu:\n$desc"
        }

        var sortAsc = true
        btn_sort_by.setOnClickListener {
            if(sortAsc){
                goodsMutList.sortedBy { it.length }
            }else{
                goodsMutList.sortedByDescending {
                    it.length
                }
            }
            var desc = ""
            for(item in goodsMutList){
                desc = "${desc}name: ${item}\n"
            }
            tv_list_result.text = "按照${if(sortAsc)"升序" else "降序"}重新排列： \n$desc"
            sortAsc = !sortAsc
        }