.net core HttpClient

最近在写项目，这里打算整理出项目中比较常用的功能。

通常我们发送http请求是在前端使用表单或者ajax，那么.net core后台发送http请求该如何呢？

这里我使用HttpClient

因为通常提交的方法是post或者get，我使用简单工厂模式来设计此功能。

using System;
using System.Collections.Generic;
using System.Text;

namespace Tools.HttpClientHelper
{
    public abstract class AbsHttpHelper
    {
        //请求的主机
        public string baseAddr = string.Empty;
        //是否启用验证
        public bool isAuth = false;
        //验证字符串
        public string auth = string.Empty;//"Bearer "+token
        //请求路径
        public string path = string.Empty;

        public abstract string GetResult();
    }
}

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;

namespace Tools.HttpClientHelper
{
    public class GetHelper: AbsHttpHelper
    {

        /// <summary>
        /// 
        /// </summary>
        /// <param name="baseAddr">访问的主机</param>
        /// <param name="auth">验证字符串</param>
        /// <param name="path">请求的路径</param>
        public GetHelper(string baseAddr, string auth, string path)
        {
            this.baseAddr = baseAddr;
            this.auth = auth;
            this.path = path;
        }

        public override string GetResult()
        {
            string resultContent = string.Empty;
            using (HttpClient client = new HttpClient())
            {
                client.BaseAddress = new Uri(baseAddr);
                var t = client.GetAsync(path);
                t.Wait();
                var result = t.Result;
                resultContent = result.Content.ReadAsStringAsync().Result;
            }
            return resultContent;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;

namespace Tools.HttpClientHelper
{
    public class PostHelper:AbsHttpHelper
    {
        //发送的数据
        private FormUrlEncodedContent content = null;

        /// <summary>
        /// 构造方法
        /// </summary>
        /// <param name="baseAddr">请求的主机</param>
        /// <param name="auth">验证字符串</param>
        /// <param name="path">请求路径</param>
        /// <param name="isAuth">是否启用验证</param>
        /// <param name="content">发送的数据</param>
        public PostHelper(string baseAddr, string auth, string path, bool isAuth, FormUrlEncodedContent content)
        {
            this.baseAddr = baseAddr;
            this.auth = auth;
            this.content = content;
            this.path = path;
            this.isAuth = isAuth;
        }

        public override string GetResult()
        {
            string resultContent = string.Empty;
            using (HttpClient client = new HttpClient())
            {
                client.BaseAddress = new Uri(baseAddr);
                if (isAuth)
                {
                    client.DefaultRequestHeaders.Add("Authorization", auth);
                }
                var t = client.PostAsync(path, content);
                t.Wait();
                var result = t.Result;
                resultContent = result.Content.ReadAsStringAsync().Result;
            }
            return resultContent;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;

namespace Tools.HttpClientHelper
{
    /// <summary>
    /// 创建http请求对象的工厂类
    /// </summary>
    public class HttpFactory
    {
        /// <summary>
        /// 创建http请求对象
        /// </summary>
        /// <param name="method">get/post</param>
        /// <param name="baseAddr">请求的主机</param>
        /// <param name="auth">验证字符串</param>
        /// <param name="path">请求路径</param>
        /// <param name="isAuth">是否启用验证，get请求时为false</param>
        /// <param name="content">发送的数据,get请求时为null</param>
        /// <returns></returns>
        public AbsHttpHelper CreateHttpHelper(string method, string baseAddr, string auth, string path, bool isAuth, FormUrlEncodedContent content)
        {
            AbsHttpHelper helper = null;
            method = method.ToLower();
            switch (method)
            {
                case "get":
                    helper = new GetHelper(baseAddr, auth, path);
                    break;
                case "post":
                    helper = new PostHelper(baseAddr, auth, path, isAuth, content);
                    break;
            }
            return helper;
        }
    }
}

调用：

HttpFactory httpFactory = new HttpFactory();
            AbsHttpHelper helper = httpFactory.CreateHttpHelper("get", baseAddr, "", path, false, null);
            string rs = helper.GetResult();

注意，这里的post方法只支持表单的键值对提交，content 如下

            var content = new FormUrlEncodedContent(new[] {
                    new KeyValuePair<string, string>("apiCode", "GetUser"),
                    new KeyValuePair<string, string>("pCount", "10"),
                    new KeyValuePair<string, string>("pNum", "1")
                    });

如果要传json，则需使用StringContent，如下：

protected async Task SendMsgAsync(string touser, string msg)
        {
            string sendMsgPath = AppConfig.CreateConfig().sendMsgPath + AccessTokenJob.token; //发送的路径
            var msgObj = new { content = msg };

            var content = new
            {
                touser = touser,
                msgtype = "text",
                AppConfig.CreateConfig().agentid,
                text = msgObj,
                safe = 0
            };
            var jsonStr = Newtonsoft.Json.JsonConvert.SerializeObject(content);
            StringContent contentStr = new StringContent(jsonStr);
            using (HttpClient client = new HttpClient())
            {
                var respMsg = await client.PostAsync(sendMsgPath, contentStr);
                string msgBody = await respMsg.Content.ReadAsStringAsync();
            }
        }