Android spinner 初始屏蔽默认值

fun Spinner.onItemSelectedListener(body: (position: Int) -> Unit) {
    var isFirst = true
    onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
        override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
            body(position)
            if (isFirst){
                view.setVisible(false)
                isFirst = false
            }else{
                view.setVisible(true)
            }
        }

        override fun onNothingSelected(parent: AdapterView<*>?) {
        }
    }
}