How to know list of key-values we can pass to object type parameters in Html Helpers in .net MVC

Question

Is there any way we can check list of key-value pairs we can pass to Html Helpers in .net MVC. Let's see the below example:

For Html.TextBox example is there any way I can get a list of values I can pass in the First and second parameters?

For RoutLink Example same question how can I check which values I can pass in object routValues parameter?