using (WebClient webClient = new WebClient()){
byte[] dataArr = webClient.DownloadData("url.jpg");
//save file to local
File.WriteAllBytes(@"path.png", dataArr);
}
public static bool DownloadImage(string imageUrl, string filename, ImageFormat format)
{
WebClient client = new WebClient();
Stream stream = client.OpenRead(imageUrl);
Bitmap bitmap;
bitmap = new Bitmap(stream);
if(bitmap != null)
bitmap.Save(filename, format);
stream.Flush();
stream.Close();
client.Dispose();
return File.Exists(filename);
}