【WebAPI】新手入门WebAPI

一、前言

      工作也有一年多了，从进入公司就一直进行BIM（建筑信息模型）C/S产品的研发，平时写的最多的就是Dev WPF。一个偶然的时机，产品需要做支付宝扫码与微信扫码，所以需要了解产品服务器中的授权服务是如何编写的，以此开始接触Web。本篇将以小白的视角学习Webapi，老司机可以直接略过。

二、Webapi编写

        Step1:  编写WebApiConfig.cs，这个不用多说，就是设置路由嘛。

 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 }
         );
    }
 }

Step2:  在Global.asax文件中初始化路由映射。

public class MvcApplication : System.Web.HttpApplication
{
     protected void Application_Start()
     {
        AreaRegistration.RegisterAllAreas();
        WebApiConfig.Register(GlobalConfiguration.Configuration);
     }
}

Step3:  创建controller，编写Api具体服务。

public class TestController: ApiController
{
       [HttpGet]
       public string ConnectionTest()
       {
            return "connected_success";
       }

       [HttpPost]
       public HttpResponseMessage GetInfo(string value1， string value2)
       {           
            var info = new Info()
            {
               Property1 = value1,
               Property2 = value2,
               Property3 = "3"
            };
            HttpResponseMessage response = new HttpResponseMessage
            {
                StatusCode = HttpStatusCode.OK,
                Content = new StringContent(JsonConvert.SerializeObject(info), Encoding.GetEncoding("UTF-8"),"application/json")
            };
            return response;
      }
}

这样，一个简单的实例就编写好了。根据之前的路由映射规则："api/{controller}/{action}/{id}"，我们的访问地址就是：http://xxx.xxx.com:xxx/api/Test/GetName

三、Webapi的请求

       api写完了，总要去请求这个api服务的吧，那么我们得首先明白HttpGet与HttpPost两种请求方式的区别。从字面上来说，Get是获取，Post是投递、推送的意思。结合其它资料我觉得以下解释还是比较容易理解的：

下面就是两种请求方式的写法，包括前台与后台的写法。前台以ajax，后台就是C#。

         Method1： Get请求写法

         前台Get请求写法：

//无参数
$.ajax({
    url: "/api/controllerName/ActionName
    type: "GET",
    success: function (data)
    {
       //
    }
})

//带参数
$.ajax({
    url: "/api/controllerName/ActionName
    type: "GET",
    data:{"property1":value1,"property2":value2},
    success: function (data)
    {
       //
    }
})

或者

$.ajax({
    url: "/api/controllerName/ActionName/?property1="+value1+"&property2="+value2,
    type: "GET",
    success: function (data)
    {
       //
    }
})

后台Get请求写法：

public static void TestGet(string serverAddress)
{
    try
    {
         HttpClient httpsClient = new HttpClient
         {
                 BaseAddress = new Uri(serverAddress),
                 Timeout = TimeSpan.FromMinutes()
         };

         if (DsClientOperation.ConnectionTest(httpsClient)) //这里是连接测试判断，可根据业务自行调整
         {
           stringGetUrl = httpsClient.BaseAddress + "api/ControllerName/ActionName"; //若带参，参数写在url里，例：xxx.com?order=参数1
           Uri address = new Uri(PostUrl);
           Task<HttpResponseMessage> response = httpsClient.GetAsync(address);
           response.ContinueWith(
           (getTask) =>
           {
               if (getTask.IsFaulted)
               {
                   throw getTask.Exception;
               }
                   HttpResponseMessage getResponse = getTask.Result;
               getResponse.EnsureSuccessStatusCode();
               var result = getResponse.Content.ReadAsStringAsync().Result;
               return result;
            });
         }
   }
   catch
   {

   }
}

 public static bool ConnectionTest(string serverAddress)
 {
      if (string.IsNullOrEmpty(serverAddress)) return false;
      HttpClient httpClient = new HttpClient
      {
           BaseAddress = new Uri(serverAddress),
           Timeout = TimeSpan.FromSeconds()
      };

      Uri address = new Uri(httpClient.BaseAddress + "api/Test/ConnectionTest");
      Task<HttpResponseMessage> task = httpClient.GetAsync(address);
      try
      {
           task.Wait();
      }
      catch
      {
          return false;
      }

      HttpResponseMessage response = task.Result;
      if (!response.IsSuccessStatusCode)
          return false;

      string connectionResult;
      try
      {
          var result = response.Content.ReadAsStringAsync().Result;
          connectionResult = JsonConvert.DeserializeObject<string>(result);
      }
      catch
      {
          return false;
      }
      return connectionResult.Equals("connected_success");
  }

Method2： Post请求写法

前台Post请求写法：

//无参数
 $.ajax({
        url: "api/ControllerName/ActionName",
        type: "Post",
        success: function (data) {

        }
    });

//有1个参数  
 $.ajax({ 
        url: "api/ControllerName/ActionName",         
        type: "Post", dataType: "json", 
        contentType: "application/json",
        data:{"":value1}, 
        success: function (data) { } }); 

//有2个参数
 $.ajax({
        url: "api/ControllerName/ActionName",
        type: "Post",
        dataType: "json",
        contentType: "application/json",
        data:JSON.stringify({"property1":value1,"property2":value2}), success: function (data) { } }); 

//再多的话要封装成对象进行传输了
最重要的是Action里的参数有[FromBody]标签，并且FromBody只能写一次

[HttpPost]
public HttpResponseMessage Action([FromBody]dynamic yourparameter)

[HttpPost]
public HttpResponseMessage Action([FromBody]JObject yourparameter)

后台Post请求写法：

public static void TestPost(string productName, string serverAddress)
{
      var productName = "Your Product";
      var requestCode = "Your Number";
      var clientDictionary = new Dictionary<string, string>
      {
             {"ProductName", productName},
             {"RequestCode", requestCode},
       };

      var packageInfo = JsonConvert.SerializeObject(clientDictionary);
      if (!string.IsNullOrEmpty(packageInfo))
      {
           try
           {
                 HttpClient httpsClient = new HttpClient
                 {
                        BaseAddress = new Uri(serverAddress),
                        Timeout = TimeSpan.FromMinutes()
                 };

                 if (DsClientOperation.ConnectionTest(httpsClient)) //这里是连接测试判断，可根据业务自行调整
                 {
                        StringContent strData = new StringContent(
                                                           packageInfo,
                                                           Encoding.UTF8,
                                                           "application/json");
                        string PostUrl = httpsClient.BaseAddress + "api/ControllerName/ActionName";
                        Uri address = new Uri(PostUrl);
                        Task<HttpResponseMessage> response = httpsClient.PostAsync(address, strData);
                        response.ContinueWith(
                            (postTask) =>
                            {
                                if (postTask.IsFaulted)
                                {
                                    throw postTask.Exception;
                                }
                                HttpResponseMessage postResponse = postTask.Result;
                                postResponse.EnsureSuccessStatusCode();
                                var result = postResponse.Content.ReadAsStringAsync().Result;                                
                                return result;
                            });
                    }
                }
             catch
             {

             }
        }
  }

四、结尾

       大致就写到这里，如果有写错的地方可以在评论区留言，下一篇玩玩其它的，继续以小白视角研究研究MVC。