C# 編寫Web API

1）創建Web API項目

打開VS2012->FILE->New->Project->Web->ASP.NET MVC 4 Web Application, 修改名字為WebAPIApplication, 單擊OK, 在Project Template中選擇Web API,單擊OK.

2）添加Controller Template選擇Empty API controller名字為StudentValueController.cs代碼如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace MvcApplication22.Controllers
{
    public class StudentValueController : ApiController
    {
        /// <summary>  
        /// 根據搜索條件獲取學生信息  
        /// GET /api/StudentValue/GetStudents?stuName=chad&stuAddress=jiaxing  
        /// </summary>  
        /// <param name="name">姓名</param>  
        /// <param name="address">地址</param>  
        /// <returns>滿足條件的學生信息</returns>  
        [HttpGet]
        public IEnumerable<StudentInfo> GetStudents(string stuName, string stuAddress)
        {
            using (DataClassesDataContext dcdc = new DataClassesDataContext())
            {
                List<StudentInfo> items = dcdc.StudentInfos.ToList();
                if (stuName != null)
                {
                    items = items
                        .Where(u => u.stuName.Contains(stuName)).ToList();
                }
                if (stuAddress != null)
                {
                    items = items
                        .Where(u => u.stuAddress.Contains(stuAddress)).ToList();
                }
                return items;
            }
        }
        /// <summary>  
        /// 根據學生編號獲取學生信息  
        /// GET /api/StudentValue/GetStudentById/{id}  
        /// </summary>  
        /// <param name="id">編號</param>  
        /// <returns>學生信息</returns>  
        [HttpGet]
        public StudentInfo GetStudentById(int id)
        {
            using (DataClassesDataContext dcdc = new DataClassesDataContext())
            {
                return dcdc.StudentInfos
                    .FirstOrDefault(u => u.stuId.Equals(id));
            }
        }
        /// <summary>  
        /// 添加學生信息  
        /// POST /api/StudentValue/AddStudent  
        /// {stuName:'jack', stuAddress:'jiangsu'}  
        /// </summary>  
        /// <param name="item">學生信息</param>  
        /// <returns>添加成功返回學生信息, 否則返回null</returns>  
        [HttpPost]
        public StudentInfo AddStudent(StudentInfo item)
        {
            try
            {
                using (DataClassesDataContext dcdc = new DataClassesDataContext())
                {
                    dcdc.StudentInfos.InsertOnSubmit(item);
                    dcdc.SubmitChanges();
                    return item;
                }
            }
            catch (Exception ex)
            {
                return null;
            }
        }
        /// <summary>  
        /// 修改學生信息  
        /// PUT /api/StudentValue/UpdateStudent/{id}  
        /// {stuName:'jack', stuAddress:'jiangsu'}  
        /// </summary>  
        /// <param name="id">編號</param>  
        /// <param name="item">新的學生信息</param>  
        /// <returns>更新成功返回學生信息, 否則返回null</returns>  
        [HttpPut]
        public StudentInfo UpdateStudent(int id, StudentInfo item)
        {
            try
            {
                using (DataClassesDataContext dcdc = new DataClassesDataContext())
                {
                    StudentInfo newItem = dcdc.StudentInfos
                        .FirstOrDefault(u => u.stuId == id);
                    newItem.stuName = item.stuName;
                    newItem.stuAddress = item.stuAddress;
                    dcdc.SubmitChanges();
                    return newItem;
                }
            }
            catch (Exception ex)
            {
                return null;
            }
        }
        /// <summary>  
        /// 刪除學生信息  
        /// DELETE /api/StudentValue/DeleteStudent/{id}  
        /// </summary>  
        /// <param name="id">編號</param>  
        /// <returns>刪除成功返回true, 否則返回false</returns>  
        [HttpDelete]
        public bool DeleteStudent(int id)
        {
            try
            {
                using (DataClassesDataContext dcdc = new DataClassesDataContext())
                {
                    StudentInfo item = dcdc.StudentInfos
                        .FirstOrDefault(u => u.stuId.Equals(id));
                    dcdc.StudentInfos.DeleteOnSubmit(item);
                    dcdc.SubmitChanges();
                    return true;
                }
            }
            catch (Exception ex)
            {
                return false;
            }
        }
    }
}  

3）修改WebApiConfig.cs內容如下，主要是修改API訪問路徑

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace MvcApplication2
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{action}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }
}

4）用Firefox RESTClient測試編寫的API

提示：在Body中添加json數據時請在Headers中添加Content-Type: application/json

修改WebAPI返回數據的樣式如將返回樣式改成JSON:
在Global.asax.cs添加方法
/// <summary>
/// 設置WebAPI返回的樣式(XML或者JSON)
/// </summary>
/// <param name="config"></param>
void ConfigureApi(HttpConfiguration config)
{
// Remove the JSON formatter
//config.Formatters.Remove(config.Formatters.JsonFormatter);
// or
// Remove the XML formatter
config.Formatters.Remove(config.Formatters.XmlFormatter);
}
並在方法Application_Start中調用
ConfigureApi(GlobalConfiguration.Configuration);

 

MVC4發布到IIS，出現HTTP 錯誤 404.0 - Not Found的解決方法。
1）Web Site所對應的Application Pool的.NET Framework Version改成v4.0。
2）由於使用的是VS2012,只要在MVC根目錄的web.config中添加
<system.webServer>
<modules runAllManagedModulesForAllRequests="true" />
</system.webServer>
就行了