2018.11.2

btn_set_for.setOnClickListener {
            var desc = ""
            for (item in goodsMutSet){
                desc = "${desc}名称： ${item}\n"
            }
            tv_set_result.text = "lalala\n$desc"
        }

        btn_set_iterator.setOnClickListener {
            var desc = ""
            val iterator = goodsMutSet.iterator()
            while(iterator.hasNext()){
                val item = iterator.next()
                desc = "${desc}name: ${item} \n"
            }
            tv_set_result.text = "la: \n$desc"
        }

        btn_set_foreach.setOnClickListener {
            var desc = ""
            goodsMutSet.forEach{
                desc = "${desc}name: ${it}\n"
            }
            tv_set_result.text = "labu:\n$desc"
        }