前端使用AngularJS的$resource,后端ASP.NET Web API，实现增删改查
AngularJS中的$resource服务相比$http服务更适合与RESTful服务进行交互。本篇后端使用ASP.NET Web API, 前端使用$resource，实现增删改查。
本系列包括：
1、前端使用AngularJS的$resource,后端ASP.NET Web API，实现增删改查
2、前端使用AngularJS的$resource,后端ASP.NET Web API，实现分页、过滤
领域和上下文
首先领域先行。
public class StudentVm { [Key] public int Id { get; set; } public string Name { get; set; } public string Age { get; set; } }
上下文。
public class StudentContext : DbContext { public StudentContext() : base("conn") { Database.SetInitializer(new StudentInitializer()); } public DbSet<StudentVm> Students { get; set; } }
上下文的构造函数中，StudentIntializer类对数据进行了初始化。
public class StudentInitializer : CreateDatabaseIfNotExists<StudentContext> { protected override void Seed(StudentContext context) { IList<StudentVm> students = new List<StudentVm>(); students.Add(new StudentVm() { Name = "aa", Age = "20" }); students.Add(new StudentVm() { Name = "bb", Age = "18" }); students.Add(new StudentVm() { Name = "cc", Age = "22" }); students.Add(new StudentVm() { Name = "dd", Age = "23" }); students.Add(new StudentVm() { Name = "ee", Age = "20" }); students.Add(new StudentVm() { Name = "ff", Age = "21" }); students.Add(new StudentVm() { Name = "gg", Age = "28" }); foreach(StudentVm student in students) { context.Students.Add(student); } base.Seed(context); } }
对于EF Code First来说，Web.config中需要配置连接字符串。
<connectionStrings>
<add name="conn"
connectionString="Data Source=.;User=yourname;Password=yourpassword;Initial Catalog=StudentsDemo;Integrated Security=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
Repository
在这里使用上下文类，实现增删改查。
public class StudentsReop { private StudentContext _db = new StudentContext(); public IEnumerable<StudentVm> Query() { return _db.Students; } public StudentVm Get(int id) { return _db.Students.SingleOrDefault(s => s.Id == id); } //更新 public void Put(int id, StudentVm student) { var stu = _db.Students.SingleOrDefault(s => s.Id == id); _db.Students.Attach(stu); _db.Entry(stu).State = System.Data.Entity.EntityState.Modified; _db.Entry(stu).CurrentValues.SetValues(student); _db.SaveChanges(); } //添加 public void Post(StudentVm student) { _db.Students.Add(student); _db.SaveChanges(); } public void Delete(int id) { var student = _db.Students.SingleOrDefault(s => s.Id.Equals(id)); _db.Students.Remove(student); bool saveFailed; do { saveFailed = false; try { _db.SaveChanges(); } catch (DbUpdateConcurrencyException ex) { saveFailed = true; //重新加载数据库中的实体，使之处于unchanged的状态 ex.Entries.Single().Reload(); } } while (saveFailed); } }
API控制器
public class StudentsController : ApiController { private StudentsReop _reop = new StudentsReop(); //GET api/Students public HttpResponseMessage Get() { var students = _reop.Query().ToList(); return Request.CreateResponse(HttpStatusCode.OK, students); } //GET api/Students/5 public HttpResponseMessage Get(int id) { var student = _reop.Get(id); return Request.CreateResponse(HttpStatusCode.OK, student); } //POST api/Students public void Post([FromBody]StudentVm student) { _reop.Post(student); } //PUT api/Students/5 public void Put(int id, [FromBody]StudentVm student) { _reop.Put(id, student); } //DELETE api/Students public void Delete(int id) { _reop.Delete(id); } }
允许跨域访问
默认情况下，ASP.NET Web API是不支持跨域访问的。为了支持，需要安装Microsoft.AspNet.WebApi.Cors。安装之后，需要在全局配置生效。在WepApiConfig.cs中配置如下：
public static class WebApiConfig { public static void Register(HttpConfiguration config) { // Web API 配置和服务 // Web API 路由 config.MapHttpAttributeRoutes(); config.EnableCors(new EnableCorsAttribute("*", "*", "*")); config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); } }
在本地，浏览器中：http://localhost:49621/api/Students
前端准备
后端完成，前端在WebStorm下安装先安装需要的几个插件：
npm install angular
npm install angular-route
npm install angular-resource
npm install angular-cookies
npm install alertify
再来了解下前端的文件结构：
app.js 主module，路由都在这里配置
index.html 主视图，引用所有的css,js文件，提供让其它部分视图呈现的一块区域<div ng-view></div>
.....service/ 自定义服务，$resouce的核心就封装在这里
..........studentService.js
.....controller/
..........studentsCtrl.js 列表
..........studentUpdateCtrl.js 更新
..........studentCreateCtrl.js 添加
.....views/
..........Students.html 列表
..........StudentInfo.html 更新
..........StudentCreate.html 添加
index.html
<!DOCTYPE html> <html lang="en" ng-app="studentManagement"> <head> <meta charset="UTF-8"> <title>{{title}}</title> <link rel="stylesheet" href="node_modules/alertify/themes/alertify.core.css"/> </head> <body> <div> <p> <a href="#/">Students</a> <a href="#/Create">Create Student</a> </p> </div> <div ng-view></div> <script src="node_modules/angular/angular.min.js"></script> <script src="node_modules/angular-route/angular-route.min.js"></script> <script src="node_modules/angular-resource/angular-resource.min.js"></script> <script src="node_modules/angular-cookies/angular-cookies.min.js"></script> <script src="node_modules/alertify/lib/alertify.min.js"></script> <script src="app.js"></script> <script src="service/studentService.js"></script> <script src="controller/studentUpdateCtrl.js"></script> <script src="controller/studentsCtrl.js"></script> <script src="controller/studentCreateCtrl.js"></script> </body> </html>
以上，主视图中，需要注意引用js文件的顺序，一般angualr相关方在最上面，然后app对应js文件，最后是各种服务和控制器相关js文件。
app.js
在这里，当然首先要定义一个module，定义module的时候要把所有用到的module依赖写在module方法的第二个实参里。还有一个主项工作就是定义设置路由，而且，如果想让以后视同从controller中拿数据更快，我们还可以利用路由的resolve机制，把数据从某处读取出来，先放到路由中，然后在controller中把resolve机制下的数据读出来。
"use strict"; var studentsManagement = angular.module("studentManagement",["ngResource","ngCookies","ngRoute"]) .run(function($rootScope){ $rootScope.title = "Home"; }) .config(["$routeProvider","$locationProvider", function($routeProvider, $locationProvider){ //关于url的基本配置 //$locationProvider.html5Mode({ // enabled: true, // requireBase: false //}); //配置路由 $routeProvider.when("/", { templateUrl: "views/Students.html", controller: "studentsCtrl", resolve: { students: function($q,studentDataService){ //$q异步执行方法 var deferred = $q.defer(); studentDataService.query(function(data){ deferred.resolve(data); }); return deferred.promise; } } }).when("/Student/:id",{ templateUrl: "views/StudentInfo.html", controller: "studentUpdateCtrl", resolve: { student: function($q, studentDataService, $route){ var defered = $q.defer(); //从路由中获取id的值 var id = $route.current.params.id; studentDataService.get({id: id}, function(data){ defered.resolve(data); }); return defered.promise; } } }).when("/Create",{ templateUrl: "views/CreateStudent.html", controller: "studentCreateCtrl" }); }]);
● 使用$routeProvider配置路由的过程就是让一对对view和controller结婚的过程
● 显示列表的时候通过路由的resolve机制把数据先放在了路由中
● 显示某个Sudent的时候也通过路由的resolve机制把数据先放在了路由中
●/Student/:id这个路由格式中的id代表变量，可借助$route服务从路由中取出来var id = $route.current.params.id;
studentService.js
在这里，封装了对API的所有请求。
而$resource服务是位于angular-resource中，大致按如下调用：
$resource(url,{paramDefaults},{actions},{options});
其中，第一个参数是必须的，其它都optional。
angular.module('studentManagement').factory("studentDataService",["$resource", function($resource){
var baseUrl = "http://localhost:49621/api/Students";
return $resource("http://localhost:49621/api/Students",{},{
query: {method: "GET", isArray: true },
create: {method: "POST"},
get: {method: "GET", url: baseUrl + "?id=:id"},
remove: {method: "DELETE", url: baseUrl + "?id=:id"},
update: {method: "PUT", url: baseUrl + "?id=:id"}
})
}]);
以上，在"?id=:id"中，冒号后面的id是一个变量，在controller中通过对象传递到这里来，比如 studentDataService.remove({id: id}).$promise.then(...)
列表，studentsCtr.j和views/Students.html这对恋人
studentsCtr.js：
angular.module('studentManagement').controller("studentsCtrl",['$scope','$route','$rootScope','studentDataService', function($scope,$route, $rootScope, studentDataService){
$rootScope.title = "Students";
$scope.students = $route.current.locals.students;//students在路由resolve中定义
$scope.removeStudent = function(id, student){
studentDataService.remove({id: id}).$promise.then(function(){
//获取student在当前集合中的索引
var index = $scope.students.indexOf(student);
$scope.students.splice(index, 1);
alertify.log(student.Name + ' is removed');
});
};
}]);
以上，students的数据并没有向那个源头发出请求获取，而是直接使用$route服务，把路由resolve机制中的变量值取了出来。删除数据实际是做2件事，一件是删除服务端的数据，一件是删除model中的数据。
Students.html:
<table> <thead> <tr> <th>Name</th><th>Age</th><th>Actions</th> </tr> </thead> <tbody> <tr ng-repeat="student in students"> <td>{{student.Name}}</td> <td>{{student.Age}}</td> <td> <a href="#/Student/{{student.Id}}">更新</a> <a href="javascript:void(0)" ng-click="$parent.removeStudent(student.Id, student)">移除</a> </td> </tr> </tbody> </table>
添加，studentCreateCtrl.js和views/CreateStudent.html这对恋人
studentCreateCtrl.js：
angular.module('studentManagement').controller("studentCreateCtrl", ["$scope", "studentDataService", '$rootScope', "$location", function ($scope, studentDataService, $rootScope, $location) {
$rootScope.title = "Create student";
$scope.saveStudent = function (student) {
studentDataService.create(student).$promise.then(function (res) {
$location.path('/');
});
};
}]);
CreateStudent.html：
<form> <input id="userName" ng-model="student.Name" /> <br/> <input id="userAge" ng-model="student.Age" /> <br/> <button ng-click="saveStudent(student)">Save</button> <button type="reset">Cancel</button> </form>
更新，studentUpdateCtrl.js和views/StudentInfo.html这对恋人
studentUpdateCtrl.js：
angular.module('studentManagement').controller("studentUpdateCtrl",["$scope","$route","$rootScope","studentDataService","$location", function($scope,$route, $rootScope, studentDataService, $location){
//student是在resolve中定义的
$scope.student = $route.current.locals.student;
$rootScope.title = "Student Info -" + $scope.student.Name;
$scope.updateInfo = function(student){
studentDataService.update({id: student.Id}, student).$promise.then(function(){
$location.url("/");
alertify.log("Updated Student Scucess");
});
};
}]);
StudentInfo.html：
<form> <input type="text" id="userName" ng-model="student.Name"/> <br/> <input type="text" id="userAge" ng-model="student.Age"/> <br/> <button ng-click="updateInfo(student)">Update</button> <button type="reset">Reset</button> </form>
待续~~
