In this article, I will show you how to remove the file extension and just display the file name using Path.GetFileNameWithoutExtension() method.
string fileWithoutExtension = Path.GetFileNameWithoutExtension(FileUpload1.FileName);
lblAlternateText.Text = fileWithoutExtension;
The debugging result showing file extension was removed from the image.
While uploading the image I needed to get the alternate text from the image. So that I wanted to remove the file extension from the image.