1、生成微信小程序二维码，需要获取微信小程序Access_Token。代码如下，先获取Access_Token
/// <summary>/// 获取微信小程序Access_Token/// </summary>/// <param name="appId">小程序唯一凭证</param>/// <param name="appSecret">小程序唯一凭证密钥</param>/// <returns></returns>public static string GetAccessToken(string appId, string appSecret){ string access_token = string.Empty; try { string token_url = $"https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={appId}&secret={appSecret}"; HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(token_url); //请求方式 myRequest.Method = "GET"; HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse(); Stream stream = myResponse.GetResponseStream(); XmlDictionaryReader xmlReader = JsonReaderWriterFactory.CreateJsonReader(stream, XmlDictionaryReaderQuotas.Max); xmlReader.Read(); string xml = xmlReader.ReadOuterXml(); myResponse.Close(); stream.Close(); stream.Dispose(); XmlDocument doc = new XmlDocument(); doc.LoadXml(xml); XmlElement rootElement = doc.DocumentElement; access_token = rootElement.SelectSingleNode("access_token").InnerText.Trim(); return access_token; } catch (Exception ex) { throw ex; }}2、生成微信小程序二维码，无限次数
/// <summary>/// 生成微信小程序二维码/// </summary>/// <param name="picPath"></param>/// <param name="access_token"></param>/// <param name="paramData"></param>/// <param name="page"></param>/// <param name="width"></param>public static void GetWeChatCodeLimit(string picPath, string access_token, string paramData = null, string page = null, int width = 430){ try {//这个路径生成的二维码是无限次数，scene参数最大32位string url = $"https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token={access_token}";Dictionary<string, object> dic = new Dictionary<string, object>();if (string.IsNullOrWhiteSpace(paramData)){ paramData = "id=123";}dic.Add("scene", paramData); //必填，有不能为空，随便填好了if (!string.IsNullOrWhiteSpace(page)){ dic.Add("path", page); //注意这里要用 path，而不是用page，官网有问题}dic.Add("width", width);string json = JsonHelper.GetJSON<Dictionary<string, object>>(dic);HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(url);myRequest.Method = "POST";myRequest.ContentType = "application/json;charset=UTF-8";byte[] payload = Encoding.UTF8.GetBytes(json);myRequest.ContentLength = payload.Length;Stream writer = myRequest.GetRequestStream();writer.Write(payload, 0, payload.Length);writer.Close();HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();Stream stream = myResponse.GetResponseStream();//返回图片数据流byte[] byteArray = StreamToBytes(stream);//将数据流转为byte[]if (byteArray.Length > 1000){ File.WriteAllBytes(picPath, byteArray);}else{ //转字符串--报错 string str = Encoding.Default.GetString(byteArray); throw new Exception(str);}myResponse.Close();stream.Close();stream.Dispose(); } catch (Exception ex) {throw ex; }}3、生成微信小程序二维码，有限次数
/// <summary>/// 生成微信小程序二维码/// </summary>/// <param name="picPath"></param>/// <param name="access_token"></param>/// <param name="paramData"></param>/// <param name="page"></param>/// <param name="width"></param>public static void CreateWeChatQrCode(string picPath, string access_token, string paramData = null, string page = null, int width = 430){ try {//这个路径有限次数，1000，000个，要注意使用//string url = $"https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode?access_token={access_token}";//这个生成是小程序码，上面是二维码string url = $"https://api.weixin.qq.com/wxa/getwxacode?access_token={access_token}";if (!string.IsNullOrWhiteSpace(paramData)){ page += "?" + paramData;}Dictionary<string, object> dic = new Dictionary<string, object>();dic.Add("path", page); //必填dic.Add("width", width);string json = JsonHelper.GetJSON<Dictionary<string, object>>(dic);HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(url);myRequest.Method = "POST";myRequest.ContentType = "application/json;charset=UTF-8";byte[] payload = Encoding.UTF8.GetBytes(json);myRequest.ContentLength = payload.Length;Stream writer = myRequest.GetRequestStream();writer.Write(payload, 0, payload.Length);writer.Close();HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();Stream stream = myResponse.GetResponseStream();//返回图片数据流byte[] byteArray = StreamToBytes(stream);//将数据流转为byte[]if (byteArray.Length > 1000){ File.WriteAllBytes(picPath, byteArray);}else{ //转字符串 string str = Encoding.Default.GetString(byteArray); throw new Exception(str);}myResponse.Close();stream.Close();stream.Dispose(); } catch (Exception ex) {throw ex; }} /// <summary>/// 将数据流转为byte[]/// </summary>/// <param name="stream"></param>/// <returns></returns>public static byte[] StreamToBytes(Stream stream){ List<byte> bytes = new List<byte>(); int temp = stream.ReadByte(); while (temp != -1) { bytes.Add((byte)temp); temp = stream.ReadByte(); } return bytes.ToArray();} 小程序端实现https://www.jianshu.com/p/0522d455d492
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