把页面上的图片保存到本地

调用腾讯的二维码接口，需要把二维码图片保存到本地

public string SendQCode(string studentid)

{

if (studentid != "")

{

QrCodeApi qrcode = new QrCodeApi();

string QRCode = qrcode.GetQrcode( studentid);

string qcurl = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=" + QRCode;

string path = Server.MapPath("~/Data/image/" + studentid + ".jpg");

//判断二维码图片是否存在，如果存在删除

if (File.Exists(path))

{

//File.Delete(Path.GetFullPath(path));

File.Delete(path);

}

//直接保存二维码到本地

Downloader.SaveQrCodeImage(qcurl, path);

return "http://....../image/" + studentid + ".jpg";

}

else

{

return "";

}

}

主要做的是保存方法SaveQrCodeImage

/// <summary>

/// 根据Ticket获取二维码图片保存在本地

/// </summary>

/// <param name="scene_id">二维码场景id</param>

/// <param name="imgPath">图片存储路径</param>

public static void SaveQrCodeImage(string url, string imgPath)

{

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);

req.Method = "GET";

using (WebResponse wr = req.GetResponse())

{

HttpWebResponse myResponse = (HttpWebResponse)req.GetResponse();

string strpath = myResponse.ResponseUri.ToString();

WebClient mywebclient = new WebClient();

try

{

mywebclient.DownloadFile(strpath, imgPath);

}

catch (Exception ex)

{

throw new Exception("获取二维码图片失败！");

//throw ex;

}

}

}

还有一种是由于二维码过期所以

自己在项目中专业建一个图片页面，访问该页面会加载图片。

由于做了两次封装，故此 先调用腾讯的接口，返回的是图片路径，之后在保存改路经资源返回

public void GetTengxunQCode(string studentid)

{

if (studentid != "")

{

QrCodeApi qrcode = new QrCodeApi();

string QRCode = qrcode.GetQrcode(studentid);

prlimg = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=" + QRCode;

WebClient wc = new WebClient();

byte[] b = wc.DownloadData(prlimg);

Response.ContentType = "image/jpg";

Response.BinaryWrite(b);

Response.Flush();

Response.End();

}

}

用WebClient类

WebClient wc = new WebClient();

byte[] b = wc.DownloadData(prlimg);

Response.ContentType = "image/jpg";

Response.BinaryWrite(b);

Response.Flush();

Response.End();

即可