参考：https://www.jb51.net/article/172955.htm
1

<div class="type-select">
	<select name="selected" id="" class="form-control m-b" v-model="selected" @change="getRoleSelected">
		<option :value="role.id" v-for="role in roleList">{{role.roleName}}</option>
	</select>
</div>

2

roleList: {},
selected: ''

3

getRoles: function() {
		var _this = this;
		var url = this.projectName + '/role/getRoles';
		$.ajax({
			url: url,
			type: 'get',
			dataType: 'json',
			success: function(result) {
				if (result.status == 200) {
					console.log(result.data);
					_this.roleList = result.data;
					//如果没有这句代码，select中初始化会是空白的，默认选中就无法实现
					_this.selected = _this.roleList[0].id;

			}

		}
	});
},
getRoleSelected: function() {
		//获取选中的违规类型：value值
		console.log(this.selected);
},

完整js代码:

	new Vue({
				el: '#wrapper',
				data: {
					projectName: '',
					loginuser: {
						id: '',
						roleName: '',
						loginName: '',
						realName: '',
						roles: [],
						status: ''
					},
					roleList: {},
					selected: ''
				},
				created: function() {
					//获取项目名
					this.getProjectName();
					//获取登录用户信息
					this.getLoginUser();
					//获取可用角色
					this.getRoles();
				},
				mounted: function() {

				},
				methods: {
					getProjectName: function() {
						var curWwwPath = window.document.location.href;
						var pathName = window.document.location.pathname;
						var pos = curWwwPath.indexOf(pathName);
						var localhostPaht = curWwwPath.substring(0, pos);
						var projectName = pathName.substring(0, pathName.substr(1).indexOf('/') + 1);
						this.projectName = projectName;
					},
					getLoginUser: function() {
						var url = this.projectName + '/user/getloginUser';
						var _this = this;
						$.ajax({
							url: url,
							type: 'get',
							dataType: 'json',
							success: function(result) {
								console.log(result);
								if (result.status == 200) {
									console.log(result.data);
									_this.loginuser = result.data;
									_this.loginuser.roleName = result.data.roles[1].roleName;
								}
							}
						});
					},
					outloginBtn: function() {
						var here = confirm('确定要退出吗？');
						if (here) {
							var url = this.projectName + '/user/outLogin';
							$.ajax({
								url: url,
								type: 'get',
								dataType: 'json',
								success: function(result) {
									console.log(result);
								}
							});
						}
					},
					getRoles: function() {
						var _this = this;
						var url = this.projectName + '/role/getRoles';
						$.ajax({
							url: url,
							type: 'get',
							dataType: 'json',
							success: function(result) {
								if (result.status == 200) {
									console.log(result.data);
									_this.roleList = result.data;
									//如果没有这句代码，select中初始化会是空白的，默认选中就无法实现
									_this.selected = _this.roleList[0].id;

								}

							}
						});
					},
					getRoleSelected: function() {
						//获取选中的违规类型
						console.log(this.selected);
					},

				}

			});

详解：