将文件的扩展名更改为cshtml，然后根据需要添加相关的剃刀代码。

I want to change the GUI of my project. I am using ready-made bootstrap templates as I am not a good designer. I have my own back-end code but I like some .html pages from those template. I am not able to add it as a view to that controller.

Change the extension of the file to cshtml then add the relevant razor code as needed.