How to apply a master slide on exisiting slides (C# .NET)

Hi,all
i am a new man for slides.i wanna apply a template to the ppt file.I found a methord below
https://docs.aspose.com/display/slidesnet/Apply+a+theme+to+a+presentation
do as the above methord after,but it just has been inserted into the ppt file ,has not been applied to per page.now how to apply the master which i inserted to per page?
pls help me

@udigger,

I have observed your requirements and like to share that in the sample code and new master is added in a presentation. I think your case is that you have some source presentation on which you want to apply the template. Once you have new master copied/cloned in target presentation. You need to traverse all or desired slides on which you need to apply the layout slides of new master. But in doing this you have to be sure that when you are changing the master of any slide or slides, it belongs to some specific layout slide in master. The new master should have the same layout slide available to so that when you apply new master slide or template slide the operation is successful.

		ISlide slide = pres.Slides[0];
		slide.LayoutSlide.MasterSlide = newMasterSlides;