页面转cavas,图片跨域问题

前台img，src地址为http://...............此时可正常显示

当整个页面转Cavas时，此时图片会产生跨域问题

解决方案：后台请求图片，转为base64,给前台绑定

//获取图片并转为base64
        private string Base64(string imgUrl)
        {
            WebRequest webRequest = WebRequest.Create(imgUrl);
            WebResponse webResponse = webRequest.GetResponse();
            Bitmap myImage = new Bitmap(webResponse.GetResponseStream());

            MemoryStream ms = new MemoryStream();
            myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            return Convert.ToBase64String(ms.ToArray());
        }

转好后，需进一步处理

 url = "data:image/png;base64," + Base64(url);

必须加上 data:image/png;base64,