Mvc display PDF on the page

Today, we can see that the requirement is to display a pdf file on the page. After a long time, there is no effect, and sometimes there are various incompatible effects, which are quite speechless. After a long time, I couldn't help it. I went to Google and introduced various plug-ins and methods, but they were complicated. I didn't like plug-ins very much, but sometimes I cannot write it myself, so it will be used. Plug-ins are not used for this function. There are few codes.

FileStreamResult readPDF (fName = dirp = export src = (FileSystemInfo fsi (fsi = x = s = (fi. name = dirp ++ fi. name; ViewBag. title = fi. name; = File (fs,