original = new Bitmap(this.Size.Width, this.Size.Height);
Graphics gr = Graphics.FromImage(original);
gr.CopyFromScreen(this.Location.X, this.Location.Y, 0, 0, original.Size);
form1.getImage(original);
original.Save("C:\\Users\\park\\Desktop\\test\\justest.jpeg", ImageFormat.Jpeg); // no error
original.Save("C:\\Users\\park\\Desktop\\test\\justest.jpeg"+DateTime.Now.ToString("HH:mm")); // error
I tried Path.Combine() as well, but got the same error(path format is not supported).