微信第三方登录

string returnUrl = string.Empty;
            string appId = ConfigurationManager.AppSettings["wx_AppKey"];
            string appSecret = ConfigurationManager.AppSettings["wx_AppSecret"];

            var weixinOAuth = new WeiXinOAuth();
            string code = Request.QueryString["code"];
            string state = Request.QueryString["state"];

            if (string.IsNullOrEmpty(code) || code == "authdeny")
            {
                if (string.IsNullOrEmpty(code))
                {
                    //发起授权(第一次微信握手)
                    string authUrl = weixinOAuth.GetWeiXinCode(appId, appSecret, Server.UrlEncode(Request.Url.ToString()), true);
                    Response.Redirect(authUrl, true);
                }
                else
                {
                    // 用户取消授权
                    ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Error, "授权失败！");
                }
            }
            else
            {
                //获取微信的Access_Token（第二次微信握手）
                var modelResult = weixinOAuth.GetWeiXinAccessToken(appId, appSecret, code);
                //获取微信的用户信息(第三次微信握手)
                var userInfo = weixinOAuth.GetWeiXinUserInfo(modelResult.SuccessResult.access_token, modelResult.SuccessResult.openid);
                //用户信息（判断是否已经获取到用户的微信用户信息）
                if (userInfo.Result && userInfo.UserInfo.openid != "")
                {
                    //根据OpenId判断数据库是否存在，如果存在，直接登录即可
                    if (CurrentUser != null)
                    {
                        if (AccountBindings.GetUser(2, userInfo.UserInfo.openid) == null)
                        {
                            AccountBinding account = new AccountBinding();
                            account.AccountType = 2;
                            account.Identification = userInfo.UserInfo.openid;
                            account.UserID = CurrentUser.UserID;
                            account.OauthToken = modelResult.SuccessResult.access_token;
                            account.OauthTokenSecret = appSecret;
                            AccountBindings.CreateAccountBinding(account);

                            ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Success, "绑定成功");
                        }
                        else
                        {
                            ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Hint, "此账号已在网站中绑定过，不可再绑定其他网站账号");
                        }
                    }
                    else
                    {
                        User systemUser = AccountBindings.GetUser(2, userInfo.UserInfo.openid);
                        if (systemUser != null)
                        {
                            FormsAuthentication.SetAuthCookie(systemUser.UserName, true);
                            returnUrl = SiteUrls.Instance().UserDomainHome(systemUser);
                            ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Success, "登录成功");
                        }
                        else
                        {
                            ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Success, string.Empty);
                            ViewData["UserName"] = WebUtils.UrlEncode(userInfo.UserInfo.nickname);
                            string nickName = WebUtils.UrlEncode(userInfo.UserInfo.nickname);
                            string figureurl = userInfo.UserInfo.headimgurl;
                            ViewData["FirstLogin"] = true;
                            returnUrl = SPBUrlHelper.Action("ThirdRegister", "ChannelUser", new RouteValueDictionary { { "accountType", 2 }, { "openID", userInfo.UserInfo.openid }, { "OauthToken", modelResult.SuccessResult.access_token }, { "OauthTokenSecret", appSecret }, { "nickName", nickName }, { "figureurl", figureurl } });
                        }
                    }
                }
                else
                {
                    ViewData["StatusMessageData"] = new StatusMessageData(StatusMessageType.Error, "参数错误，授权失败！");
                }
            }

            ViewData["returnUrl"] = returnUrl;
            return View("Pages/User/LoginCallback.aspx");

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Net;
using System.IO;
using System.Collections.Specialized;
using System.Text.RegularExpressions;
using System.Globalization;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using SpaceBuilder.Common;
using Jayrock.Json.Conversion;
using System.Configuration;


public class WeiXinOAuth
{
    public enum Method { GET, POST, PUT, DELETE };
    /// <summary>
    /// 获取微信Code
    /// </summary>
    /// <param name="appId">微信AppId</param>
    /// <param name="appSecret">微信AppSecret</param>
    /// <param name="redirectUrl">返回的登录地址，要进行Server.Un编码</param>
    /// <param name="isWap">true=微信内部登录 false=pc网页登录</param>
    public string GetWeiXinCode(string appId, string appSecret, string redirectUrl, string state, bool isWap)
    {
        var r = new Random();
        //微信登录授权
        //string url = "https://open.weixin.qq.com/connect/qrconnect?appid=" + appId + "&redirect_uri=" + redirectUrl +"&response_type=code&scope=snsapi_login&state=STATE#wechat_redirect";
        //微信OpenId授权
        //string url = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=" + appId + "&redirect_uri=" + redirectUrl +"&response_type=code&scope=snsapi_login&state=STATE#wechat_redirect";
        //微信用户信息授权
        var url = "";
        if (isWap)
        {
            url = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=" + appId + "&redirect_uri=" +
                  redirectUrl + "&response_type=code&scope=snsapi_userinfo&state=" + state + "#wechat_redirect";
        }
        else
        {
            url = "https://open.weixin.qq.com/connect/qrconnect?appid=" + appId + "&redirect_uri=" + redirectUrl +
                  "&response_type=code&scope=snsapi_login&state=" + state + "#wechat_redirect";
        }
        return url;
    }
    /// <summary>
    /// 通过code获取access_token
    /// </summary>
    /// <param name="appId"></param>
    /// <param name="appSecret"></param>
    /// <param name="code"></param>
    /// <returns></returns>
    public WeiXinAccessTokenResult GetWeiXinAccessToken(string appId, string appSecret, string code)
    {
        string url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=" + appId + "&secret=" + appSecret +
          "&code=" + code + "&grant_type=authorization_code";
        string jsonStr = _WebRequest(Method.GET, url, ""); 
        var result = new WeiXinAccessTokenResult();
        if (jsonStr.Contains("errcode"))
        {
            var errorResult = (WeiXinHelper.WeiXinErrorMsg)JsonConvert.Import(typeof(WeiXinHelper.WeiXinErrorMsg), jsonStr);
            result.ErrorResult = errorResult;
            result.Result = false;
        }
        else
        {
            var model = (WeiXinAccessTokenModel)JsonConvert.Import(typeof(WeiXinAccessTokenModel), jsonStr);
            result.SuccessResult = model;
            result.Result = true;
        }
        return result;
    }
    /// <summary>
    /// 拉取用户信息
    /// </summary>
    /// <param name="accessToken"></param>
    /// <param name="openId"></param>
    /// <returns></returns>
    public WeiXinHelper.WeiXinUserInfoResult GetWeiXinUserInfo(string accessToken, string openId)
    {
        string url = "https://api.weixin.qq.com/sns/userinfo?access_token=" + accessToken + "&openid=" + openId + "⟨=zh_CN";
        string jsonStr = _WebRequest(Method.GET ,url,"");
        var result = new WeiXinHelper.WeiXinUserInfoResult();
        if (jsonStr.Contains("errcode"))
        {
            var errorResult = (WeiXinHelper.WeiXinErrorMsg)JsonConvert.Import(typeof(WeiXinHelper.WeiXinErrorMsg), jsonStr);
            result.ErrorMsg = errorResult;
            result.Result = false;
        }
        else
        {
            var userInfo = (WeiXinHelper.WeiXinUserInfo)JsonConvert.Import(typeof(WeiXinHelper.WeiXinUserInfo), jsonStr);
            result.UserInfo = userInfo;
            result.Result = true;
        }
        return result;
    }


    private string _WebRequest(Method method, string url, string postData)
    {
        HttpWebRequest webRequest = null;
        StreamWriter requestWriter = null;
        string responseData = "";

        webRequest = System.Net.WebRequest.Create(url) as HttpWebRequest;
        webRequest.Method = method.ToString();
        webRequest.ServicePoint.Expect100Continue = false;

        if (method == Method.POST)
        {
            webRequest.ContentType = "application/x-www-form-urlencoded";
            requestWriter = new StreamWriter(webRequest.GetRequestStream());
            try
            {
                requestWriter.Write(postData);
            }
            catch
            {
                throw;
            }
            finally
            {
                requestWriter.Close();
                requestWriter = null;
            }
        }

        responseData = _WebResponseGet(webRequest);

        webRequest = null;

        return responseData;

    }

    private string _WebResponseGet(HttpWebRequest webRequest)
    {
        StreamReader responseReader = null;
        string responseData = "";
        try
        {
            responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream());
            responseData = responseReader.ReadToEnd();
        }
        catch
        {
            throw;
        }
        finally
        {
            webRequest.GetResponse().GetResponseStream().Close();
            responseReader.Close();
            responseReader = null;
        }

        return responseData;
    }
}

/// <summary>
/// 通过code获取access_token 请求成功的实体
/// </summary>
public class WeiXinAccessTokenModel
{
    /// <summary>
    /// 接口调用凭证
    /// </summary>
    public string access_token { get; set; }
    /// <summary>
    /// access_token接口调用凭证超时时间，单位（秒）
    /// </summary>
    public int expires_in { get; set; }
    /// <summary>
    /// 用户刷新access_token
    /// </summary>
    public string refresh_token { get; set; }
    /// <summary>
    /// 授权用户唯一标识
    /// </summary>
    public string openid { get; set; }
    /// <summary>
    /// 用户授权的作用域，使用逗号（,）分隔
    /// </summary>
    public string scope { get; set; }
}

public class WeiXinAccessTokenResult
{
    public WeiXinAccessTokenModel SuccessResult { get; set; }
    public bool Result { get; set; }

    public WeiXinHelper.WeiXinErrorMsg ErrorResult { get; set; }
}

/// <summary>
    /// 微信帮助类
    /// </summary>
public class WeiXinHelper
    {
        /// <summary>
        /// 微信错误访问的情况
        /// </summary>
        public class WeiXinErrorMsg
        {
            /// <summary>
            /// 错误编号
            /// </summary>
            public int errcode { get; set; }
            /// <summary>
            /// 错误提示消息
            /// </summary>
            public string errmsg { get; set; }
        }
 
        /// <summary>
        /// 获取微信用户信息
        /// </summary>
        public class WeiXinUserInfoResult
        {
            /// <summary>
            /// 微信用户信息
            /// </summary>
            public WeiXinUserInfo UserInfo { get; set; }
            /// <summary>
            /// 结果
            /// </summary>
            public bool Result { get; set; }
            /// <summary>
            /// 错误信息
            /// </summary>
            public WeiXinErrorMsg ErrorMsg { get; set; }
        }
 
        /// <summary>
        /// 微信授权成功后，返回的用户信息
        /// </summary>
        public class WeiXinUserInfo
        {
            /// <summary>
            /// 用户的唯一标识
            /// </summary>
            public string openid { get; set; }
            /// <summary>
            /// 用户昵称
            /// </summary>
            public string nickname { get; set; }
            /// <summary>
            /// 用户的性别，值为1时是男性，值为2时是女性，值为0时是未知
            /// </summary>
            public string sex { get; set; }
            /// <summary>
            /// 用户个人资料填写的省份
            /// </summary>
            public string province { get; set; }
            /// <summary>
            /// 普通用户个人资料填写的城市
            /// </summary>
            public string city { get; set; }
            /// <summary>
            /// 国家，如中国为CN
            /// </summary>
            public string country { get; set; }
            /// <summary>
            /// 用户头像，最后一个数值代表正方形头像大小（有0、46、64、96、132数值可选，0代表640*640正方形头像），用户没有头像时该项为空
            /// </summary>
            public string headimgurl { get; set; }
            /// <summary>
            /// 用户特权信息，json 数组，如微信沃卡用户为（chinaunicom）
            /// </summary>
            public string[] privilege { get; set; }
            /// <summary>
            /// 用户统一标识,针对一个微信开放平台帐号下的应用，同一用户的unionid是唯一的
            /// </summary>
            public string unionid { get; set; }
        }
    }