[.NET WebAPI系列03] WebAPI Controller 中标准CRUD方法

【因】

　　　WebAPI的Controller中，通常都是下面四种方法：

　　对应于数据操做是咱们一般所说的CRUD.

　　C对应post,R对应Get，U对应Put，D对应Delete。

　　直接模仿VS 2012 WebAPI项目模板中的CRUD方法，R传回的是要查的值，CUD都是空，这样虽然也知足逻辑，

　　可是一旦出错，没有有效的错误处理机制，如上一节Controller中的方法,虽然也能够使用,但不适合做为商用项目中的标准方法.

　　因此在此总结出较标准的CRUD方法模板，以供参考。

 

【果】

　　改编自第一节中的CRUD方法

　　1.Read

　　1)GET  api/courses/id

　　不一样于之前返回的是要查找的对象,如今返回的是HttpResponseMessage对象，其中能够包含要返回的对象值，一旦出错，会有恰当的

　　错误代码及信息返回。

 1 // GET api/courses/id
 2         public HttpResponseMessage Get(int id)
 3         { 
 4             HttpResponseMessage msg=null;
 5             var ret=(from c in courses
 6                      where c.id==id
 7                      select c).FirstOrDefault();
 8             //todo: if null- should return 404
 9             if (ret == null)
10             {
11                 msg = Request.CreateErrorResponse(HttpStatusCode.NotFound, "Course not found");
12             }
13             else
14             {
15                 msg = Request.CreateResponse<course>(HttpStatusCode.OK, ret);
16             }
17             return msg;
18         }

　　

     2.Create

 　　Post   api/courses/

 1 // Post api/courses
 2         public HttpResponseMessage Post([FromBody]course c)
 3         {
 4             c.id = courses.Count;
 5             courses.Add(c);
 6             //TODO:: should return a 201 with a location head
 7             var msg = Request.CreateResponse(HttpStatusCode.Created);
 8             msg.Headers.Location = new Uri(Request.RequestUri + c.id.ToString());
 9             return msg;
10         }

    

　　3.Update

 1  // Put api/courses/id
 2         public HttpResponseMessage Put(int id, [FromBody]course c)
 3         {
 4             HttpResponseMessage msg = null;
 5             var ret = (from v in courses
 6                        where v.id == c.id
 7                        select v).FirstOrDefault();
 8             if (ret == null)
 9             {
10                 msg = Request.CreateErrorResponse(HttpStatusCode.NotFound, "Course not found");
11             }
12             else
13             {
14                 ret.title = c.title;
15                 msg = Request.CreateResponse<course>(HttpStatusCode.Accepted, ret);
16                 msg.Headers.Location = new Uri(Request.RequestUri + c.id.ToString());
17             }
18             return msg;
19         }

    

　　 4.Delete

 1  // Delete api/courses/id
 2         public HttpResponseMessage Delete(int id)
 3         {
 4             HttpResponseMessage msg = null;
 5             var ret = (from c in courses
 6                        where c.id == id
 7                        select c).FirstOrDefault();
 8             
 9             if (ret == null)
10             {
11                 msg = Request.CreateErrorResponse(HttpStatusCode.NotFound, "Course not found");
12             }
13             else
14             {
15                 courses.Remove(ret);
16                 msg = Request.CreateResponse<course>(HttpStatusCode.Gone, ret);
17             }
18             return msg;
19         }