构建API

前言

过程，如图：

第一步创建一个帮助类，类里面提供了加密、组装Url等方法，代码如下：

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.IO;
 using System.Net;
 using System.Security.Cryptography;
 using System.Text; 

 namespace APIClient.Content
 {
     public class WebHelper
     {

         #region 获得客户端时间+ public static int GetTimeZ(DateTime time)
         public static int GetTimeZ(DateTime time)
         {
             var startTime = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(, , ));
             return (int)(time - startTime).TotalSeconds;
         }
         #endregion

         #region 加密key+private string CreateSign(Dictionary<string, string> paramList, string appKey)
         public static string CreateSign(Dictionary<string, string> paramList, string appKey)
         {
             var str = paramList.OrderBy(c => c.Key).Aggregate(string.Empty, (current, item) => current + item.Value);
             return MD5(str + appKey).ToLower();//调用MD5
         }
         #endregion

         #region 执行HTTP GET请求+ public static string DoGet(string url, IDictionary<string, string> parameters)
         public static string DoGet(string url, IDictionary<string, string> parameters)
         {
             if (parameters != null && parameters.Count > )
             {
                 if (url.Contains("?"))
                 {
                     url = url + "&" + BuildPostDate(parameters); //调用BuildPostDate
                 }
                 else
                 {
                     url = url + "?" + BuildPostDate(parameters);
                 }
             }

             HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
             req.Method = "GET";
             req.KeepAlive = true;
             req.UserAgent = "ADCSDK";
             req.ContentType = "application/x-www-form-urlencoded;charset=utf-8";
             HttpWebResponse rsp = (HttpWebResponse)req.GetResponse();
             Encoding encoding = Encoding.GetEncoding(rsp.CharacterSet);
             return GetResponseAsString(rsp, encoding); //调用GetResponseAsString
         }

         #endregion

         #region MD5加密+ public static string MD5(string input)
         /// <summary>
         /// MD5加密 （添加命名空间；using System.Security.Cryptography;）
         /// </summary>
         /// <param name="input">输入字符串</param>
         /// <returns>加密后的字符串</returns>
         public static string MD5(string input)
         {
             if (string.IsNullOrEmpty(input))
             {
                 return string.Empty;
             }

             var md5 = new MD5CryptoServiceProvider();
             var inputBytes = Encoding.UTF8.GetBytes(input);
             var outPutbytes = md5.ComputeHash(inputBytes);
             return BitConverter.ToString(outPutbytes).Replace("-", "");
         }
         #endregion

         #region 组装普通文本请求参数+ private static string BuildPostDate(IDictionary<string, string> parameters)
         private static string BuildPostDate(IDictionary<string, string> parameters)
         {
             StringBuilder postDate = new StringBuilder();
             bool hasParam = false;
             IEnumerator<KeyValuePair<string, string>> dem = parameters.GetEnumerator();
             while (dem.MoveNext())
             {
                 string name = dem.Current.Key;
                 string value = dem.Current.Value;
                 if (!string.IsNullOrEmpty(name) && !string.IsNullOrEmpty(value))
                 {
                     if (hasParam)
                     {
                         postDate.Append("&");
                     }
                     postDate.Append(name);
                     postDate.Append("=");
                     postDate.Append(Uri.EscapeDataString(value));
                     hasParam = true;
                 }
             }
             return postDate.ToString();
         }
         #endregion

         #region 把响应流转换为文本+ private static string GetResponseAsString(HttpWebResponse rsp, Encoding encoding)
         private static string GetResponseAsString(HttpWebResponse rsp, Encoding encoding)
         {
             StringBuilder result = new StringBuilder();
             Stream stream = null;
             StreamReader reader = null;

             try
             {
                 stream = rsp.GetResponseStream();
                 reader = new StreamReader(stream, encoding);
                 var buffer = new char[];
                 int readBytes;
                 while ((readBytes = reader.Read(buffer, , buffer.Length)) > )
                 {
                     result.Append(buffer, , readBytes);
                 }
             }
             finally
             {
                 if (reader != null) reader.Close();
                 if (stream != null) stream.Close();
                 if (rsp != null) rsp.Close();
             }
             return result.ToString();
         }
         #endregion

     }
 }

第二步服务器端创建一个API（参数协商定义），代码如下：

  public ActionResult Reg(int productId, string version, string source, string userName, string timeZ, string sign)
         {
             if (string.IsNullOrEmpty(version))
                 return Content("productId");
             if (string.IsNullOrEmpty(version))
                 return Content("version");
             if (string.IsNullOrEmpty(version))
                 return Content("source");
             if (string.IsNullOrEmpty(version))
                 return Content("userName");
             if (string.IsNullOrEmpty(version))
                 return Content("timeZ");
             if (string.IsNullOrEmpty(version))
                 return Content("sign1");

             var dict = new Dictionary<string, string>
                            {
                                {"productId", productId.ToString()},
                                {"version", version},
                                {"source", source},
                                {"userName", userName},
                                {"timeZ", timeZ},
                            };

             var checkSign =WebHelper.CreateSign(dict, "zz680000f7-6834");//sign 是数据库中一个key，这里是为了方便，应当是根据productId值从数据库中取出相应的key与程序传过来的key比较

             if (sign.ToLower() != checkSign.ToLower())
             {
                 return Content("sign2");
             }
             //调用接口之后还应当在数据库中插入一条日志数据
             return Content("");
         } 

第三步应用程序创建一个方法，请求API，代码如下：

  public ActionResult List()
         {
             RegTest();
             return View();
         }
         //参数
         private const string APIUrl = "http://localhost:4023/APISever/";
         private const int ProductId = ;
         private const string AppKey = "zz680000f7-68341";//680000f7-6834-4b5f-8534-70cea7fd641b

         //注册接口
         public void RegTest()
         {
             var url = string.Format("{0}reg", APIUrl);
             var dict = new Dictionary<string, string>
                            {
                                 {"productId", ProductId.ToString()},
                                {"version", "1.0.0.1"},
                                {"source", "lg"},
                                {"userName", "zlzl"},
                                {"timeZ",WebHelper.GetTimeZ(DateTime.Now).ToString()},//调用GetTimeZ
                            };

             dict["sign"] =WebHelper.CreateSign(dict, AppKey);//调用CreateSign

             var result = WebHelper.DoGet(url, dict);//调用DoGet
             Response.Write(string.Format("注册接口测试结果：{0}",result));
         }