ASP.NET Core使用HttpClient的同步和异步请求

using System;

using System.Collections.Generic;

using System.Collections.Specialized;

using System.IO;

using System.Linq;

using System.Net;

using System.Net.Http;

using System.Text;

using System.Threading.Tasks;

using System.Web;

namespace Common

{

    public class HttpHelper

    {/// <summary>

        /// 发起POST同步请求

        ///

        /// </summary>

        /// <param name="url"></param>

        /// <param name="postData"></param>

        /// <param name="contentType">application/xml、application/json、application/text、application/x-www-form-urlencoded</param>

        /// <param name="headers">填充消息头</param>

        /// <returns></returns>

        public static string HttpPost(string url, string postData = null, string contentType = null, int timeOut = , Dictionary<string, string> headers = null)

        {

            postData = postData ?? "";

            using (HttpClient client = new HttpClient())

            {

                if (headers != null)

                {

                    foreach (var header in headers)

                        client.DefaultRequestHeaders.Add(header.Key, header.Value);

                }

                using (HttpContent httpContent = new StringContent(postData, Encoding.UTF8))

                {

                    if (contentType != null)

                        httpContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(contentType);

                    HttpResponseMessage response = client.PostAsync(url, httpContent).Result;

                    return response.Content.ReadAsStringAsync().Result;

                }

            }

        }

        /// <summary>

        /// 发起POST异步请求

        /// </summary>

        /// <param name="url"></param>

        /// <param name="postData"></param>

        /// <param name="contentType">application/xml、application/json、application/text、application/x-www-form-urlencoded</param>

        /// <param name="headers">填充消息头</param>

        /// <returns></returns>

        public static async Task<string> HttpPostAsync(string url, string postData = null, string contentType = null, int timeOut = , Dictionary<string, string> headers = null)

        {

            postData = postData ?? "";

            using (HttpClient client = new HttpClient())

            {

                client.Timeout = new TimeSpan(, , timeOut);

                if (headers != null)

                {

                    foreach (var header in headers)

                        client.DefaultRequestHeaders.Add(header.Key, header.Value);

                }

                using (HttpContent httpContent = new StringContent(postData, Encoding.UTF8))

                {

                    if (contentType != null)

                        httpContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(contentType);

                    HttpResponseMessage response = await client.PostAsync(url, httpContent);

                    return await response.Content.ReadAsStringAsync();

                }

            }

        }

        /// <summary>

        /// 发起GET同步请求

        /// </summary>

        /// <param name="url"></param>

        /// <param name="headers"></param>

        /// <param name="contentType"></param>

        /// <returns></returns>

        public static string HttpGet(string url, Dictionary<string, string> headers = null)

        {

            using (HttpClient client = new HttpClient())

            {if (headers != null)

                {

                    foreach (var header in headers)

                        client.DefaultRequestHeaders.Add(header.Key, header.Value);

                }

                HttpResponseMessage response = client.GetAsync(url).Result;

                return response.Content.ReadAsStringAsync().Result;

            }

        }

        /// <summary>

        /// 发起GET异步请求

        /// </summary>

        /// <param name="url"></param>

        /// <param name="headers"></param>

        /// <param name="contentType"></param>

        /// <returns></returns>

        public static async Task<string> HttpGetAsync(string url, Dictionary<string, string> headers = null)

        {

            using (HttpClient client = new HttpClient())

            {if (headers != null)

                {

                    foreach (var header in headers)

                        client.DefaultRequestHeaders.Add(header.Key, header.Value);

                }

                HttpResponseMessage response = await client.GetAsync(url);

                return await response.Content.ReadAsStringAsync();

            }

        }

    }

}

调用异步请求方法：

var result = await HttpHelper.HttpPostAsync("http://www.baidu.com/api/getuserinfo", "userid=23456798");