C#判断用户是否使用微信浏览器，并据此来显示真实内容或二维码

1     string userAgent = Request.UserAgent;  
2     if (userAgent.ToLower().Contains("micromessenger"))  
3     {  
4         Response.Write("欢迎您在微信中访问我。");  
5     }  
6     else  
7     {  
8         Response.Write("请在微信中访问本页。");  
9     }  

 1     /// <summary>  
 2         /// 生成二维码  
 3         /// </summary>  
 4         private void CreateQRCode()  
 5         {  
 6             string enCodeString = Request.Url.ToString();  
 7             QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();  
 8             qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;//编码方式(注意：BYTE能支持中文，ALPHA_NUMERIC扫描出来的都是数字)  
 9             qrCodeEncoder.QRCodeScale = 10;//大小(值越大生成的二维码图片像素越高)  
10             qrCodeEncoder.QRCodeVersion = 0;//版本(注意：设置为0主要是防止编码的字符串太长时发生错误)  
11             qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;//错误效验、错误更正(有4个等级)  
12       
13             string filename = Request.Url.ToString().Replace("/", "").Replace("\", "").Replace(".", "").Replace(":", "").Replace("?", "").Replace("&", "") + ".jpg";  
14             string path = Server.MapPath("~/qrcode/");  
15             if (!File.Exists(path + filename))  
16             {  
17                 Bitmap bt = qrCodeEncoder.Encode(enCodeString, Encoding.UTF8);  
18                 if (!Directory.Exists(path))  
19                     Directory.CreateDirectory(path);  
20                 bt.Save(path + filename);  
21             }  
22             string html = "<img src='qrcode/" + filename + "' width='330px' height='330px'/>";  
23             html += "<h3>该内容仅限在微信浏览器下阅读！请用微信扫描，打开此页面！</h3>";  
24             divQRCode.InnerHtml = html;  
25         }  

1 <div >          
2 </div> 

1     string userAgent = Request.UserAgent;  
2     if (userAgent.ToLower().Contains("micromessenger"))  
3     {        
            Response.Write("欢迎您在微信中访问我。");  
4     }  
5     else  
6     {  
7         CreateQRCode();  
8     }