找到要抓取的图片地址：http://i.imgur.com/8S7OaEB.jpg
抓取的步骤：
- 请求图片路径
- 获取返回的数据
- 将数据转换为stream
- 将stream转换为Image
- 保存Image
明晰了步骤，接下来就简单了，直接上代码
public class RemoteImageCatchUtil{ ???private static string[] ImageExts = new[] { "jpg", "jpeg", "png", "bitmap", "gif" }; ???public static string Catch(string remoteImagePath, string saveFolder, int timeout = 2000) ???{ ???????try ???????{ ???????????var request = WebRequest.Create(remoteImagePath) as HttpWebRequest; ???????????request.Timeout = timeout > 0 ? timeout : 1000; ???????????using (var response = request.GetResponse() as HttpWebResponse) ???????????{ ???????????????if (response.StatusCode != HttpStatusCode.OK) ???????????????{ ???????????????????throw new Exception("远程访问失败"); ???????????????} ???????????????else ???????????????{ ???????????????????var ext = GetImageExtension(response.ContentType).ToLower(); ???????????????????if (!ImageExts.Contains(ext)) ???????????????????{ ???????????????????????throw new Exception("非图片文件"); ???????????????????} ???????????????????var stream = response.GetResponseStream(); ???????????????????var buffer = new byte[2048]; ???????????????????int count; ???????????????????using (var ms = new MemoryStream()) ???????????????????{ ???????????????????????while ((count = stream.Read(buffer, 0, buffer.Length)) != 0) ???????????????????????{ ???????????????????????????ms.Write(buffer, 0, count); ???????????????????????} ???????????????????????if (!Directory.Exists(saveFolder)) ???????????????????????{ ???????????????????????????Directory.CreateDirectory(saveFolder); ???????????????????????} ???????????????????????var imageName = Path.GetRandomFileName() + "." + ext; ???????????????????????var imagePath = Path.Combine(saveFolder, imageName); ???????????????????????var image = new Bitmap(ms); ???????????????????????image.Save(imagePath); ???????????????????????return imageName; ???????????????????} ???????????????} ???????????} ???????} ???????catch(Exception ex) ???????{ ???????????throw ex; ???????} ???} ???private static string GetImageExtension(string contentType) ???{ ???????if (contentType.StartsWith("image")) ???????{ ???????????return contentType.Split(@"/").Last(); ???????} ???????return string.Empty; ???}}注意，这里的代码仅供测试，使用时请自行完善。
【aspnetcore】抓取远程图片
原文地址：https://www.cnblogs.com/diwu0510/p/10336444.html