ASP.NET 5，Microsoft.AspNet.WebApi.Client 包，在 ASP.NET 5 beta3 中找不到错误

Question

我有 ASP.NET MVC 6 应用程序，它调用一些外部 Web 服务。 我使用本指南：http://www.asp.net/web-api/overview/advanced/calling-a-web-api-from-a-net-client 代码如下：

using System;
using System.Net.Http;
using System.Net.Http.Headers;

namespace TestService.Web.Code
{
    internal class ServiceProxy
    {
        internal string Get(string predicate)
        {
            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri("http://localhost:8001/");
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                HttpResponseMessage response = client.GetAsync(string.Format("TestService/LookupService" +
                                                                         "/GetCountries?term={0}", predicate)).Result;

                if (response.IsSuccessStatusCode)
                {
                     var answer = response.Content.ReadAsStringAsync().Result;
                     return answer;
                }

                return string.Empty;
            }
        }
    }
}

但这里有一个意想不到的问题：构建项目后我有 3 个错误：

• 错误 CS0246 找不到类型或命名空间名称“HttpClient”

• 错误 CS0246 找不到类型或命名空间名称“MediaTypeWithQualityHeaderValue”

• 错误 CS0246 找不到类型或命名空间名称“HttpResponseMessage”

看起来 Microsoft.AspNet.WebApi.Client 包版本与我的 KRE 版本不兼容。

我说的对吗？我该如何解决这个问题？

这里是 project.json 内容：

{

    "webroot": "wwwroot",
    "version": "1.0.0-*",
    "dependencies": {
    "Microsoft.AspNet.Server.IIS": "1.0.0-beta3",
    "Microsoft.AspNet.Mvc": "6.0.0-beta3",
    "Microsoft.AspNet.StaticFiles": "1.0.0-beta3",
    "Microsoft.AspNet.Server.WebListener": "1.0.0-beta3",
    "Microsoft.AspNet.Security.Cookies": "1.0.0-beta3",
    "System.Net.Http": "4.0.0-beta-22605",
    "Microsoft.AspNet.WebApi.Client": "5.2.3",
    "Microsoft.AspNet.Mvc.WebApiCompatShim": "6.0.0-beta3"
},
"frameworks": {
    "aspnet50": {
        "frameworkAssemblies": {
            "System.Net.Http": "4.0.0.0",
            "System.Net": "4.0.0.0"
        }
    },
    "aspnetcore50": {
        "dependencies": {
            "System.Net.Http": "4.0.0-beta-22605"
        }
    }
},
"exclude": [
    "wwwroot",
    "node_modules",
    "bower_components"
],
"bundleExclude": [
    "node_modules",
    "bower_components",
    "**.kproj",
    "**.user",
    "**.vspscc"
]
}

Answer 1

你基本上是对的。在您的示例中，Microsoft.AspNet.WebApi.Client` 包同时用于 clrcore 和 clr 运行时。此包只能用于 clr 运行时。

随着最新的变化（重命名和所有这些），这是一个工作部分：

using System;
using System.Net.Http;
using System.Net.Http.Headers;

public class Program
{
    public void Main(string[] args)
    {
    }

    internal class ServiceProxy
    {
        internal string Get(string predicate)
        {
            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri("http://localhost:8001/");
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                HttpResponseMessage response = client.GetAsync(string.Format("TestService/LookupService" +
                                                                         "/GetCountries?term={0}", predicate)).Result;

                if (response.IsSuccessStatusCode)
                {
                     var answer = response.Content.ReadAsStringAsync().Result;
                     return answer;
                }

                return string.Empty;
            }
        }
    }
}

project.json:

{
    "dependencies": {
    },
    "frameworks": {
        "dnx451": { 
            "dependencies": {
                                "Microsoft.AspNet.WebApi.Client": "5.2.3"
            }
        }
    }
}