微信小程序二维码的生成方式

业务需求：

客户想要一个停车优惠券的功能，需要用户微信扫描后，自动跳转到小程序中，首先明确一点，这个操作是需要调微信接口的，下面我们来实现下吧

微信开发文档：
获取不限制的小程序码

  //code为优惠券码，唯一值public void CreateXcxQrCode(string code){try{//首先建立文件夹string strDirPath = System.AppDomain.CurrentDomain.BaseDirectory + "ParkingCouponQrCoderImg"; if (!Directory.Exists(strDirPath)){Directory.CreateDirectory(strDirPath);} 
//这里需要使用小程序的appid及appsecret ，用户获取access_tokenstring URL = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + _appid + "&secret=" + appsecret + "";string Date2 = HttpGet(URL);Newtonsoft.Json.Linq.JObject _jObject = Newtonsoft.Json.Linq.JObject.Parse(Date2);string access_token = _jObject["access_token"].ToString();string page = "pages/car/carindex";//跳转的小程序路径string width = "280";//二维码大小string _url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + access_token;System.Net.HttpWebRequest request;request = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(_url);request.Method = "POST";request.ContentType = "application/json;charset=UTF-8";
//这里是参数string scene = "index=0&code=" + code;string options = "{\\"scene\\":\\"" + scene + "\\",\\"page\\":\\"" + page + "\\",\\"width\\":\\"" + width + "\\"}";byte[] payload;payload = System.Text.Encoding.UTF8.GetBytes(options);request.ContentLength = payload.Length;System.IO.Stream writer = request.GetRequestStream();writer.Write(payload, 0, payload.Length);writer.Close();System.Net.HttpWebResponse response;response = (System.Net.HttpWebResponse)request.GetResponse();System.IO.Stream s;s = response.GetResponseStream();byte[] val = StreamToBytes(s);string strdir_path=  strDirPath +"\\\\"+code + ".png";System.IO.File.WriteAllBytes(strdir_path, val);s.Dispose();writer.Dispose();string path = string.Format("/ParkingCouponQrCoderImg/{0}.png", code);//之后就是将path 更新进数据库了}catch (System.Exception ex){throw;}}       if (!Directory.Exists(strDirPath)){Directory.CreateDirectory(strDirPath);}public  byte[] StreamToBytes(System.IO.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();}