Hello,
Regarding the doc here that describes how to create an add new item template.
https://docs.microsoft.com/en-us/visualstudio/ide/how-to-create-item-templates?view=vs-2019
I cannot find any info on how to modify a file that exists in the solution when you add a new item from my created template. In the example of a .net EF core api project I want to modify startup.cs and add some lines there to a specific method when I add a
new new item using my custom new item template. Please provide any doc link, tutorial, video , sample that shows how to modify an existing source file when new item added.. Thanks