I want to add Initialization and validation code hook
lambda function for an Intent.
I see lambda function blueprints are all in Python or NodeJS.
Are there any good Lex code hook lambda function
example on .NET?
There's a very good sample for the Lex CodeHook in the BookTrip blueprint. It covers pretty much everything you need to set up your Lex Bot.
You can find the BookTrip blueprint when you create a new Lambda function using the AWS Templates if you are using the AWS Toolkit for Visual Studio.