遍历dom节点

 function selectOnchang(obj) {
            var selectedValue = obj.selectedIndex
            if (selectedValue == 0) {
                obj.parentNode.nextSibling.style.display = 'none'
                obj.parentNode.nextSibling.nextSibling.style.display = 'inline'
            }else if (selectedValue == 1) {
                obj.parentNode.nextSibling.style.display = 'inline'
                obj.parentNode.nextSibling.nextSibling.style.display = 'none'
            }
        }

 $("select[name='source_type']").each(function (index, item) {
                            $(this).val(data.cameras[index].source_type)
                            if (data.cameras[index].source_type == 0) {
                                $(this).parent('.form-group').next().hide()
                                $(this).parent('.form-group').next().next().show()
                            } else {
                                $(this).parent('.form-group').next().show()
                                $(this).parent('.form-group').next().next().hide()
                            }
                        })