微信开放平台---网站授权微信登录功能（附带源码）

1 微信开放平台：https://open.weixin.qq.com/

2 微信官方教程：https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=open1419316505&token=&lang=zh_CN

3.pc页面显示

4. 通过官方提供的文档，我们可以看出一共分4个步骤

第一步：请求CODE

第二步：通过code获取access_token

第三步：通过access_token调用接口

第4步：获取用户个人信息（UnionID机制）

 5.源码下载地址：http://pan.baidu.com/s/1pLyG66J

因代码加密：现贴出代码如下（下载后替换）：

Controllers--》DefaultController.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Text;
using System.Web;
using System.Web.Mvc;

using WebWeChat.Models;

namespace WebWeChat.Controllers
{
    public class DefaultController : Controller
    {
        #region 微信登录

        /// <summary>
        /// 微信登录
        /// </summary>
        public ActionResult WeChat()
        {
            //获得配置信息
            string oauthAppId = ConfigurationManager.AppSettings["oauth_app_id"];
            string redirectUri = ConfigurationManager.AppSettings["Redirect_uri"];
            if (oauthAppId == null)
            {
                return this.Content("出错了，您尚未配置微信相关的API信息！");
            }
            string state = Guid.NewGuid().ToString().Replace("-", "");
            this.Session["oauth_state"] = state;
            string sendUrl =
                "https://open.weixin.qq.com/connect/qrconnect?appid=" + oauthAppId +
                "&redirect_uri=" + HttpUtility.UrlEncode(redirectUri.ToLower()) +
                "&response_type=code&scope=snsapi_login&state=" + state +
                "#wechat_redirect";

            //开始发送
            return this.Redirect(sendUrl); //跳转到微信自己 指定的关联登陆页面
        }

        /// <summary>
        /// 微信登录返回action
        /// </summary>
        public ActionResult WeChatReturnUrl(string state, string code)
        {
            //取得返回参数

            if (this.Session["oauth_state"] == null || this.Session["oauth_state"].ToString() == "" ||
                state != this.Session["oauth_state"].ToString() || string.IsNullOrEmpty(code)) //若返回参数中未包含code或者state没有通过验证则提示出错
            {
                return this.Content("出错啦，state未初始化！");
            }

            //第一步：通过code来获取Access Token以及openid
            Dictionary<string, object> dic1 = WeixinHelper.get_access_token(code, state);
            if (dic1 == null || !dic1.ContainsKey("access_token"))
            {
                return this.Content("错误代码：，无法获取Access Token，请检查App Key是否正确！");
            }
            if (!dic1.ContainsKey("openid"))
            {
                return dic1.ContainsKey("errmsg")
                    ? this.Content("errcode：" + dic1["errcode"] + ",errmsg：" + dic1["errmsg"])
                    : this.Content("出错啦，无法获取用户授权Openid！");
            }

            var accessToken = dic1["access_token"].ToString();
            var refreshToken = dic1["refresh_token"].ToString();
            var openid = dic1["openid"].ToString();

            //储存获取数据用到的信息
            this.Session["oauth_name"] = "webchat";
            this.Session["oauth_access_token"] = accessToken;
            this.Session["oauth_openid"] = openid;
            this.Session["oauth_refresh_token"] = refreshToken;

            #region todo 将获取到的用户信息保存到数据库中

            #endregion

            //第二步：通过Access Token以及openid来获取用户的基本信息
            //Dictionary<string, object> dic2 = weixin_helper.get_user_info(access_token,openid);

            //第三步：跳转到指定页面
            return this.Content(this.WeChatResultJson());
        }

        /// <summary>
        /// 微信登录返回action, 处理用户信息
        /// </summary>
        public string WeChatResultJson()
        {
            if (this.Session["oauth_name"] == null || this.Session["oauth_access_token"] == null ||
                this.Session["oauth_openid"] == null)
            {
                return "{"ret":"1", "msg":"出错啦，Access Token已过期或不存在！"}";
            }
            var oauthName = this.Session["oauth_name"].ToString();
            var oauthAccessToken = this.Session["oauth_access_token"].ToString();
            var oauthOpenid = this.Session["oauth_openid"].ToString();
            var oauthRefreshToken = this.Session["oauth_refresh_token"].ToString();

            if (!WeixinHelper.check_access_token(oauthAccessToken)) //调用access_token前需判断是否过期
            {
                Dictionary<string, object> dic1 = WeixinHelper.get_refresh_token(oauthRefreshToken); //如果已过期则重新换取新的access_token
                if (dic1 == null || !dic1.ContainsKey("access_token"))
                {
                    return "{"openid":"0", "msg":"出错啦，无法获取access_token！"}";
                }
                oauthAccessToken = dic1["access_token"].ToString();
            }

            Dictionary<string, object> dic = WeixinHelper.get_user_info(oauthAccessToken, oauthOpenid);
            if (dic == null)
            {
                return "{"openid":"0", "msg":"出错啦，无法获取授权用户信息！"}";
            }
            try
            {
                StringBuilder str = new StringBuilder();
                str.Append("{");
                str.Append(""openid": "" + dic["openid"] + "", ");
                str.Append(""nickname": "" + dic["nickname"] + "", ");
                str.Append(""sex": "" + dic["sex"] + "", ");
                str.Append(""province": "" + dic["province"] + "", ");
                str.Append(""city": "" + dic["city"] + "", ");
                str.Append(""country": "" + dic["country"] + "", ");
                str.Append(""headimgurl": "" + dic["headimgurl"] + "", ");
                str.Append(""privilege": "" + dic["privilege"] + "", ");
                str.Append(""unionid": "" + dic["unionid"] + """);
                str.Append(""oauth_name": "" + oauthName + """);
                str.Append(""oauth_access_token": "" + oauthAccessToken + """);
                str.Append(""oauth_openid": "" + oauthOpenid + """);
                str.Append("}");
                return str.ToString();
            }
            catch
            {
                return "{"ret":"0", "msg":"出错啦，无法获取授权用户信息！"}";
            }
        }

        #endregion
    }
}

Models---》HttpMethods

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

namespace WebWeChat.Models
{
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    /// <summary>   A HTTP methods. </summary>
    ///
    /// <remarks>   xiaop, 2014/12/16. </remarks>
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    public static class HttpMethods
    {
        #region POST

        /// <summary>
        /// HTTP POST方式请求数据
        /// </summary>
        /// <param name="url">URL.</param>
        /// <param name="param">POST的数据</param>
        /// <returns></returns>
        public static string HttpPost(string url, string param)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.Accept = "*/*";
            request.Timeout = 15000;
            request.AllowAutoRedirect = false;

            string responseStr;

            var requestStream = new StreamWriter(request.GetRequestStream());
            requestStream.Write(param);
            requestStream.Close();

            var response = request.GetResponse();
            {
                // ReSharper disable once AssignNullToNotNullAttribute
                StreamReader reader = new StreamReader(stream: response.GetResponseStream(), encoding: Encoding.UTF8);
                responseStr = reader.ReadToEnd();
                reader.Close();
            }

            return responseStr;
        }

        #endregion

        #region Get

        /// <summary>
        /// HTTP GET方式请求数据.
        /// </summary>
        /// <param name="url">URL.</param>
        /// <returns></returns>
        public static string HttpGet(string url)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";

            //request.ContentType = "application/x-www-form-urlencoded";
            request.Accept = "*/*";
            request.Timeout = 15000;
            request.AllowAutoRedirect = false;

            string responseStr;

            var response = request.GetResponse();

            {
                // ReSharper disable once AssignNullToNotNullAttribute
                StreamReader reader = new StreamReader(stream: response.GetResponseStream(), encoding: Encoding.UTF8);
                responseStr = reader.ReadToEnd();
                reader.Close();
            }

            return responseStr;
        }

        #endregion

        #region Post With Pic

        public static string HttpPost(string url, IDictionary<object, object> param, string filePath)
        {
            string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
            byte[] boundarybytes = Encoding.ASCII.GetBytes("
--" + boundary + "
");

            HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
            wr.ContentType = "multipart/form-data; boundary=" + boundary;
            wr.Method = "POST";
            wr.KeepAlive = true;
            wr.Credentials = CredentialCache.DefaultCredentials;

            Stream rs = wr.GetRequestStream();
            string responseStr = null;

            string formdataTemplate = "Content-Disposition: form-data; name="{0}"

{1}";
            foreach (string key in param.Keys)
            {
                rs.Write(boundarybytes, 0, boundarybytes.Length);
                string formitem = string.Format(formdataTemplate, key, param[key]);
                byte[] formitembytes = Encoding.UTF8.GetBytes(formitem);
                rs.Write(formitembytes, 0, formitembytes.Length);
            }
            rs.Write(boundarybytes, 0, boundarybytes.Length);

            string headerTemplate = "Content-Disposition: form-data; name="{0}"; filename="{1}"
Content-Type: {2}

";
            string header = string.Format(headerTemplate, "pic", filePath, "text/plain");
            byte[] headerbytes = Encoding.UTF8.GetBytes(header);
            rs.Write(headerbytes, 0, headerbytes.Length);

            FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
            {
                rs.Write(buffer, 0, bytesRead);
            }
            fileStream.Close();

            byte[] trailer = Encoding.ASCII.GetBytes("
--" + boundary + "--
");
            rs.Write(trailer, 0, trailer.Length);
            rs.Close();

            WebResponse wresp = null;
            try
            {
                wresp = wr.GetResponse();
                Stream stream2 = wresp.GetResponseStream();
                if (stream2 != null)
                {
                    StreamReader reader2 = new StreamReader(stream2);
                    responseStr = reader2.ReadToEnd();
                }

                //logger.Debug(string.Format("File uploaded, server response is: {0}", responseStr));
            }
            catch (Exception)
            {
                //logger.Error("Error uploading file", ex);
                if (wresp != null)
                {
                    wresp.Close();
                }
            }
            return responseStr;
        }

        #endregion

        #region Post With Pic

        /// <summary>
        /// HTTP POST方式请求数据(带图片)
        /// </summary>
        /// <param name="url">URL</param>        
        /// <param name="param">POST的数据</param>
        /// <param name="fileByte">图片</param>
        /// <returns></returns>
        public static string HttpPost(string url, IDictionary<object, object> param, byte[] fileByte)
        {
            string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
            byte[] boundarybytes = Encoding.ASCII.GetBytes("
--" + boundary + "
");

            HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
            wr.ContentType = "multipart/form-data; boundary=" + boundary;
            wr.Method = "POST";
            wr.KeepAlive = true;
            wr.Credentials = CredentialCache.DefaultCredentials;

            Stream rs = wr.GetRequestStream();
            string responseStr = null;

            string formdataTemplate = "Content-Disposition: form-data; name="{0}"

{1}";
            foreach (string key in param.Keys)
            {
                rs.Write(boundarybytes, 0, boundarybytes.Length);
                string formitem = string.Format(formdataTemplate, key, param[key]);
                byte[] formitembytes = Encoding.UTF8.GetBytes(formitem);
                rs.Write(formitembytes, 0, formitembytes.Length);
            }
            rs.Write(boundarybytes, 0, boundarybytes.Length);

            string headerTemplate = "Content-Disposition: form-data; name="{0}"; filename="{1}"
Content-Type: {2}

";
            string header = string.Format(headerTemplate, "pic", fileByte, "text/plain"); //image/jpeg
            byte[] headerbytes = Encoding.UTF8.GetBytes(header);
            rs.Write(headerbytes, 0, headerbytes.Length);

            rs.Write(fileByte, 0, fileByte.Length);

            byte[] trailer = Encoding.ASCII.GetBytes("
--" + boundary + "--
");
            rs.Write(trailer, 0, trailer.Length);
            rs.Close();

            WebResponse wresp = null;
            try
            {
                wresp = wr.GetResponse();
                Stream stream2 = wresp.GetResponseStream();
                if (stream2 != null)
                {
                    StreamReader reader2 = new StreamReader(stream2);
                    responseStr = reader2.ReadToEnd();
                }

                // logger.Error(string.Format("File uploaded, server response is: {0}", responseStr));
            }
            catch (Exception)
            {
                //logger.Error("Error uploading file", ex);
                if (wresp != null)
                {
                    wresp.Close();
                }
            }
            return responseStr;
        }

        #endregion
    }
}

Models---》WeixinHelper

using System.Collections.Generic;
using System.Configuration;

using Newtonsoft.Json;

namespace WebWeChat.Models
{
    public static class WeixinHelper
    {
        #region 获得配置信息

        private static readonly string OauthAppId = ConfigurationManager.AppSettings["oauth_app_id"];
        private static readonly string OauthAppKey = ConfigurationManager.AppSettings["oauth_app_key"];

        #endregion

        /// <summary>
        /// 根据AppID和AppSecret获得access token(默认过期时间为2小时)
        /// </summary>
        /// <returns>Dictionary</returns>
        public static Dictionary<string, object> get_access_token()
        {
            string sendUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" +
                             WeixinHelper.OauthAppId + "&secret=" + WeixinHelper.OauthAppKey + "";

            //发送并接受返回值
            string result = HttpMethods.HttpGet(sendUrl);
            if (result.Contains("errmsg"))
            {
                return null;
            }
            try
            {
                Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
                return dic;
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 取得临时的Access Token(默认过期时间为2小时)
        /// </summary>
        /// <param name="code">临时Authorization Code</param>
        /// <param name="state">防止CSRF攻击，成功授权后回调时会原样带回</param>
        /// <returns>Dictionary</returns>
        public static Dictionary<string, object> get_access_token(string code, string state)
        {
            string sendUrl = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=" +
                             WeixinHelper.OauthAppId + "&secret=" + WeixinHelper.OauthAppKey + "&code=" + code +
                             "&grant_type=authorization_code";

            //发送并接受返回值
            string result = HttpMethods.HttpGet(sendUrl);
            if (result.Contains("errmsg"))
            {
                return null;
            }
            try
            {
                Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
                return dic;
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 根据access_token判断access_token是否过期
        /// </summary>
        /// <param name="accessToken"></param>
        /// <returns>true表示未失效</returns>
        public static bool check_access_token(string accessToken)
        {
            string sendUrl = "https://api.weixin.qq.com/sns/auth?access_token=" + accessToken + "&openid=" + WeixinHelper.OauthAppId;

            //发送并接受返回值
            string result = HttpMethods.HttpGet(sendUrl);
            try
            {
                Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
                if (dic.ContainsKey("errmsg"))
                {
                    return dic["errmsg"].ToString() == "ok";
                }
                return false;
            }
            catch
            {
                return false;
            }
        }

        /// <summary>
        /// 若fresh_token已过期则根据refresh_token取得新的refresh_token
        /// </summary>
        /// <param name="refreshToken">refresh_token</param>
        /// <returns>Dictionary</returns>
        public static Dictionary<string, object> get_refresh_token(string refreshToken)
        {
            string sendUrl =
                "https://api.weixin.qq.com/sns/oauth2/refresh_token?appid=" +
                WeixinHelper.OauthAppId + "&grant_type=refresh_token&refresh_token=" + refreshToken;

            //发送并接受返回值
            string result = HttpMethods.HttpGet(sendUrl);
            if (result.Contains("errmsg"))
            {
                return null;
            }
            try
            {
                return JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 获取登录用户自己的基本资料
        /// </summary>
        /// <param name="accessToken">临时的Access Token</param>
        /// <param name="openId">用户openid</param>
        /// <returns>Dictionary</returns>
        public static Dictionary<string, object> get_user_info(string accessToken, string openId)
        {
            //发送并接受返回值   
            string sendUrl = "https://api.weixin.qq.com/sns/userinfo?access_token=" + accessToken + "&openid=" + openId;

            //发送并接受返回值
            string result = HttpMethods.HttpGet(sendUrl);
            if (result.Contains("errmsg"))
            {
                return null;
            }

            //反序列化JSON
            Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
            return dic;
        }
    }
}

我的签名：坚持赚钱，顺便理想。