本文共 3007 字，大约阅读时间需要 10 分钟。

一、生成带参数二维码

官方文档：

1.请求地址

/// 
/// 创建二维码--Post/// 
/// 
   public string GetQrCode(){    string url = string.Format("https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token={0}", config.Access_Token);    return url;}

2.使用POST提交获取ticket 和链接地址

/// 
/// 创建二维码-带有推荐人的openid/// 
/// /// 
   public string Create(string fromuser){    string url = new LinkManage().GetQrCode();    JObject data = new JObject();    data.Add("action_name", "QR_LIMIT_STR_SCENE");    data.Add("action_info", JObject.FromObject(new    {        scene = new        {            scene_str = fromuser        }    }));    string result = NetHelper.Post(url, data.ToString());    JObject back = JObject.Parse(result);    JToken ticket = back.SelectToken("ticket");    if (ticket == null)        throw new Exception($"获取二维码失败：" + result);    return ticket.ToString();}

3.根据ticket获取二维码图片 ，就是一个地址

/// 
/// 获取二维码图片/// 
/// /// 
   public string GetQrCodeShow(string ticket){    string url = string.Format("https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket={0}"        , SecurityHelper.UrlEncode(ticket));    return url;}

二、下载二维码到本地

/// 
/// 下载二维码图片/// 
/// /// 
   public string Download(string fromuser){    //1.创建    string ticket = Create(fromuser);    //2.下载    string url = new LinkManage().GetQrCodeShow(ticket);    string filename = $"{fromuser}.jpg";    string path = AppDomain.CurrentDomain.BaseDirectory + "data/wxqrcode/" + filename;    //如果已经存在删除    if (File.Exists(path))        File.Delete(path);    //下载    DownFile(url, path);    return path;}

//下载到文件public static void DownFile(string url, string target){    try    {        WebClient _client = new WebClient();        byte[] data = _client.DownloadData(url);        File.WriteAllBytes(target, data);    }    catch (Exception ex)    {        throw new Exception("下载文件(" + target + ")失败：" + ex.Message + "|" + ex.StackTrace);    }}

三、合成二维码到海报图片

注：C#使用GDI+ 合成图片

/// 
/// 生成推荐海报,返回图片地址/// 
/// public string MergeImage(OAuthUser user){    //1.下载二维码    string qrcode = Download(user.openid);    //2.下载头像    string touxiang = AppDomain.CurrentDomain.BaseDirectory + "data/wxtx/" + user.openid + ".jpg";    if (File.Exists(touxiang))        File.Delete(touxiang);    DownFile(user.headimgurl, touxiang);    //3.合成到一张图片    string resultfile = AppDomain.CurrentDomain.BaseDirectory + "data/share/" + user.openid + ".jpg";    string bgfile = AppDomain.CurrentDomain.BaseDirectory + "assets/pages/img/qrcode.jpg";    Bitmap bit = new Bitmap(bgfile, false);    Graphics g = Graphics.FromImage(bit);    //添加二维码    Bitmap qrcodeImage = new Bitmap(qrcode);    g.DrawImage(qrcodeImage, 540, 1155, 180, 180);    //添加头像     Bitmap touxiangImage = new Bitmap(touxiang);    g.DrawImage(touxiangImage, 10, 10, 80, 80);    //添加昵称    g.DrawString(user.nickname, new Font("微软雅黑", 10, FontStyle.Regular), Brushes.White, 100, 25);    g.Dispose();    //保存    bit.Save(resultfile, ImageFormat.Jpeg);    bit.Dispose();    qrcodeImage.Dispose();    touxiangImage.Dispose();    return resultfile;}

转载地址：http://rxogi.baihongyu.com/