1、微信小程序获取Access_token：

access_token具体时效看官方文档。

using System;using System.Collections.Generic;using System.Linq;using System.Threading;using System.Web;using TT.Utilities;namespace DjwzApi.Com{    public class WeChatApi    {        public static string AppID = TT.Utilities.Config.ConfigureAppConfig.GetAppSettingsKeyValue("AppID");        public static string AppSecret = TT.Utilities.Config.ConfigureAppConfig.GetAppSettingsKeyValue("AppSecret");        private static string Access_token = "";        private static DateTime Expires_in_time = DateTime.Now;        static object lockObj = new object();        /// 
        /// 获取Access_token        /// 
        ///         ///         /// 
              public static string GetAccess_token(string AppID = null, string AppSecret = null)        {            lock (lockObj)            {                if (string.IsNullOrEmpty(Access_token) || ((DateTime.Now - Expires_in_time).TotalSeconds >= -30))                {                    lock (lockObj)                    {                        Access_token = "";                        Expires_in_time = DateTime.Now;                        AppID = AppID ?? WeChatApi.AppID;                        AppSecret = AppSecret ?? WeChatApi.AppSecret;                        string url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}";                        url = string.Format(url, AppID, AppSecret);                        var json = "";                        try                        {                            json = TT.Utilities.Web.HttpClientUti.DoGet(url);                        }                        catch (Exception ex)                        {                            System.Threading.Tasks.Task.Factory.StartNew(() => utils.LogHelper.WriteLog(ex.Message));                            throw new Exception("获取微信端access_token失败," + ex.Message);                        }                        //{"access_token":"12_TrAgGuiF64W8XPRXyFRFUK7SjzZptoa3ogS4mGKp-W-ni6dG_OoMNMbm_7q9lhYcx85xh-SNe3BUC_6Lg1H6FDMU7fUsKoG4NwN5EA-NVOCVUZg0OIdTvOmgHMgCxJQ1vWP__VvId4AJ2Bm_QYPdABAFNE","expires_in":7200}                        dynamic obj = new { access_token = "", expires_in = 0, errcode = 0, errmsg = "" };                        obj = TT.Utilities.Json.JsonHelper.DeserializeAnonymousType(json, obj);                        if (obj.errcode == 0)                        {                            Expires_in_time = DateTime.Now.AddSeconds(obj.expires_in);                            Access_token = obj.access_token;                        }                        return Access_token;                    }                }                else                {                    return Access_token;                }            }        }    }}

 

2、获取二维码

 这里实现了官网文档中提到的 接口A和接口C

using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Net;using System.Text;using System.Web;namespace DjwzApi.Com{    public class WxQrcode    {        private const string line_color = "{\"r\":\"0\",\"g\":\"0\",\"b\":\"0\"}";        /// 
        /// 接口A: 生成小程序码， 适用于需要的码数量较少的业务场景         /// 
        /// 
              public static string QrcodeA(string path, int width = 430, bool auto_color = false, string line_color = line_color, bool is_hyaline = false)        {            string url = "https://api.weixin.qq.com/wxa/getwxacode?access_token={0}";            var ACCESS_TOKEN = WeChatApi.GetAccess_token();            url = string.Format(url, ACCESS_TOKEN);            var arg = new Dictionary
      
        {               {
     "path",path},              {
     "width",width.ToString()},              //{"auto_color","false"},              //{"line_color",line_color},              //{"is_hyaline",is_hyaline.ToString()},            };            var response = TT.Utilities.Web.HttpRequest.DoPost_WebResponse(url, arg, null, 90, TT.Utilities.Web.HttpContentTypes.HttpContentTypeEnum.JSON);            return SaveImg(response);        }        /// 
       
        /// 接口C: 生成二维码， 适用于需要的码数量较少的业务场景          /// 
        /// 
               public static string QrcodeC(string path, int width = 430)        {            string url = "https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode?access_token={0}";            var ACCESS_TOKEN = WeChatApi.GetAccess_token();            url = string.Format(url, ACCESS_TOKEN);            var arg = new Dictionary
       
         {               {
     "path",path},              {
     "width",width.ToString()}            };            var response = TT.Utilities.Web.HttpRequest.DoPost_WebResponse(url, arg, null, 90, TT.Utilities.Web.HttpContentTypes.HttpContentTypeEnum.JSON);            return SaveImg(response);        }        static string SaveImg(HttpWebResponse response)        {            if (response.ContentType.ToLower() == "image/jpeg")            {                var re = TT.Utilities.Web.HttpResponse.HttpResponseStream(response);                var bytes = TT.Utilities.StreamUti.ConveertHelper.StreamToBytes(re);                string imgName = "ewm" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".jpg";                //文件存储相对于当前应用目录的虚拟目录                string basePath = "/image/";                //获取相对于应用的基目录,创建目录                string imgPath = System.AppDomain.CurrentDomain.BaseDirectory + basePath;     //通过此对象获取文件名                //StringHelper.CreateDirectory(imgPath);                System.IO.File.WriteAllBytes(HttpContext.Current.Server.MapPath(basePath + imgName), bytes);//讲byte[]存储为图片                return "/image/" + imgName;            }            else            {                //{"errcode":47001,"errmsg":"data format error hint: [Mz435a00280720]"}                return TT.Utilities.Web.HttpResponse.HttpResponseString(response);            }        }    }}
       
      

网络请求相关：

public static HttpWebRequest CreateHttpWebRequest(string url, int timeoutSecond = 90)        {            HttpWebRequest request;            //如果是发送HTTPS请求              if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))            {                //ServicePointManager.DefaultConnectionLimit = 1000;                ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);                request = WebRequest.Create(url) as HttpWebRequest;            }            else            {                request = WebRequest.Create(url) as HttpWebRequest;            }            request.Proxy = null;            request.ProtocolVersion = HttpVersion.Version11;            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;            request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate");            request.Accept = "*/*";            request.KeepAlive = false;            request.Timeout = timeoutSecond * 1000;            return request;        }

/// 
        /// 获取到HttpWebResponse对象        /// 
        /// url        /// 参数        /// 请求头参数        /// 
              public static HttpWebResponse DoPost_WebResponse(string url, Dictionary
      
        dic = null, Dictionary
       
         headerDic = null, int timeoutSecond = 90            , HttpContentTypes.HttpContentTypeEnum contentType = HttpContentTypes.HttpContentTypeEnum.JSON)        {            HttpWebRequest request = CreateHttpWebRequest(url, timeoutSecond);            request.Method = "POST";            request.ContentType = HttpContentTypes.GetContentType(contentType);            if (headerDic != null && headerDic.Count > 0)            {                foreach (var item in headerDic)                {                    request.Headers.Add(item.Key, item.Value);                }            }            if (dic != null && dic.Count > 0)            {                var jsonStr = Newtonsoft.Json.JsonConvert.SerializeObject(dic);                byte[] buffer = Encoding.UTF8.GetBytes(jsonStr);                request.ContentLength = buffer.Length;                try                {                    request.GetRequestStream().Write(buffer, 0, buffer.Length);                }                catch (WebException ex)                {                    throw ex;                }            }            else            {                request.ContentLength = 0;            }            return (HttpWebResponse)request.GetResponse();        }
       
      

public static Stream HttpResponseStream(HttpWebResponse response)        {            try            {                return response.GetResponseStream();            }            catch (Exception ex)            {                throw new Exception("获取HttpWebResponse.GetResponseStream异常,"+ex);            }        }

工具类：

public class ConveertHelper    {        /// 
        /// Stream 转 byte[]        /// 
        ///         /// 
              public static byte[] StreamToBytes(Stream stream)        {            List
      
        bytes = new List
       
        ();            int temp = stream.ReadByte();            while (temp != -1)            {                bytes.Add((byte)temp);                temp = stream.ReadByte();            }            return bytes.ToArray();        }    }
       
      

 

吐槽一下：官方文档对这个接口的说明不够完善，很多需要注意点没有明确，群里也有小伙伴遇到各种问题，如：返回格式没说明，错误原因不明确。

图片样式：

接口C生成的二维码：                                                                  接口A生成的小程序码：