C#获取用户基本信息一（关注了公众号的用户）

一、获取Code 

假设我们需要网页授权的页面的地址为redirect_uri

需要获取Code的话我们第一步是跳转到授权地址，我们第一步便是获取拼接授权地址 --采用snsapi_base方式

public partial class WebAuth : System.Web.UI.Page
    {
        string Appid = "XXXXXXXXXXXXXXXXXX";
        string redirect_uri = "http://www.xxxxx.com/wx/GetUserInfor.aspx";
        protected void Page_Load(object sender, EventArgs e)
        {

            string url = GetCodeUrl(Appid, redirect_uri);
            Response.Redirect(url);
        }

        /// <summary>
        /// 对页面是否要用授权 用snsapi_base方式 获取Code Appid是微信应用id
        /// </summary>
        /// <returns></returns>
        public string GetCodeUrl(string Appid, string redirect_uri)
        {
            return string.Format("https://open.weixin.qq.com/connect/oauth2/authorize?appid={0}&redirect_uri={1}&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect", Appid, redirect_uri);
        }

    }

当在微信中打开如下地址的时候如果授权成功，会自动跳转到页面redirect_uri?code=CODE&state=STATE，这样我们就可以获取到Code了

二、用Code换取Openid、再用Openid获取用户的基本信息

用get方法获取到json格式的数据，

{
   "access_token":"ACCESS_TOKEN",
   "expires_in":7200,
   "refresh_token":"REFRESH_TOKEN",
   "openid":"OPENID",
   "scope":"SCOPE",
   "unionid": "o6_bmasdasdsad6_2sgVt7hMZOPfL"
}

public partial class GetUserInfor : System.Web.UI.Page
    {
        string Appid = "wxceefad22b094e8a9";
        string Appsecret = "935c3d938aa26fa4f627b4926afd4b16";
        protected void Page_Load(object sender, EventArgs e)
        {
            string code = Request["code"];
            string openid = CodeGetOpenid(code);
            Dictionary<string, object> userInfor = GetUserInfo(openid);
            Response.Write(userInfor["nickname"]);
        }

        /// <summary>
        /// 用Code换取Openid
        /// </summary>
        /// <param name="Code"></param>
        /// <returns></returns>
        public string CodeGetOpenid(string Code)
        {
            string url = string.Format("https://api.weixin.qq.com/sns/oauth2/access_token?appid={0}&secret={1}&code={2}&grant_type=authorization_code", Appid, Appsecret, Code);
            string ReText = WebRequestHelper.WebRequestPostOrGet(url, "");//post/get方法获取信息 

            JavaScriptSerializer Jss = new JavaScriptSerializer();
            Dictionary<string, object> DicText = (Dictionary<string, object>)Jss.DeserializeObject(ReText);
            if (!DicText.ContainsKey("openid"))
                return "";
            return DicText["openid"].ToString();
        }

        /// <summary>
        /// 用openid换取用户信息
        /// </summary>
        /// <param name="openid">微信标识id</param>
        /// <returns></returns>
        public Dictionary<string, object> GetUserInfo(string openid)
        {
            JavaScriptSerializer Jss = new JavaScriptSerializer();
            string access_token = AccessToken.GetAccessToken();//获取access_token
            string url = string.Format("https://api.weixin.qq.com/cgi-bin/user/info?access_token={0}&openid={1}&lang=zh_CN", access_token, openid);
            Dictionary<string, object> respDic = (Dictionary<string, object>)Jss.DeserializeObject(WebRequestHelper.WebRequestPostOrGet(url, ""));
            return respDic;

            //{"subscribe":1,"openid":"oOPoPs_d7K8mVLX6--WPMSbaNl5o","nickname":"SKY","sex":1,"language":"zh_CN","city":"武汉","province":"湖北","country":"中国","headimgurl":"http:\/\/wx.qlogo.cn\/mmopen\/icayX4JkqCu1d3esVCQ8rSfXlgibQLKaD3z73qhbPln3ZhMh5oNw5243vpoVZFXDKMhTqxQ76OzY934nlm3iaulq60058VmEV5v\/0","subscribe_time":1495188935,"remark":"","groupid":0,"tagid_list":[]}

        }
    }

WebRequestHelper.WebRequestPostOrGet 方法如下：

public class WebRequestHelper
    {
        public static string WebRequestPostOrGet(string posturl, string postData)
        {
            Stream outstream = null;
            Stream instream = null;
            StreamReader sr = null;
            HttpWebResponse response = null;
            HttpWebRequest request = null;
            Encoding encoding = Encoding.UTF8;

            byte[] data = encoding.GetBytes(postData);
            // 准备请求...
            try
            {
                // 设置参数
                request = WebRequest.Create(posturl) as HttpWebRequest;
                CookieContainer cookieContainer = new CookieContainer();
                request.CookieContainer = cookieContainer;
                request.AllowAutoRedirect = true;
                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
                request.ContentLength = data.Length;
                outstream = request.GetRequestStream();
                outstream.Write(data, , data.Length);
                outstream.Close();
                //发送请求并获取相应回应数据
                response = request.GetResponse() as HttpWebResponse;
                //直到request.GetResponse()程序才开始向目标网页发送Post请求
                instream = response.GetResponseStream();
                sr = new StreamReader(instream, encoding);
                //返回结果网页（html）代码
                string content = sr.ReadToEnd();
                return content;
            }
            catch (Exception ex)
            {
                string err = ex.Message;
                return string.Format("{\"errcode\":-2,\"errmsg\":\"{0}\"}", err);
            }
        }
    }

说明：以上代码本人也是在网上搜索根本别人的代码综合参考改写而来。

如需要获取“未关注公众号的用户信息”，这个本人项目中还没有遇到，仅提供参考链接：http://www.cnblogs.com/net-xiejun/p/4632711.html