var path = @"C:UsersEsatDesktopBilimResimler1620855_759701257391419_1132489417_n.jpg";

System.IO.FileInfo myImageFile = new System.IO.FileInfo(path);

Console.WriteLine(myImageFile.Name); // gives 1620855_759701257391419_1132489417_n.jpg

string imageNameAndPath=@"C:UsersEsatDesktopBilimResimler1620855_759701257391419_1132489417_n.jpg"
    imageNameAndPath=imageNameAndPath.Substring(0, imageNameAndPath.LastIndexOf('/'));

string FileName = Path.GetFileName(Path)

var path = @"C:UsersEsatDesktopBilimResimler1620855_759701257391419_1132489417_n.jpg";
        string ImgPath = path.Substring(path.LastIndexOf(@"") + 1);