jQuery passing params to MVC Controller. Why are my params empty?

Answer 1

I'm not sure but I wonder if the members of GetUserRequest need to be public properties rather than public fields?

Answer 2

SendAjax(urlMethod, jsonData, ReturnGetUsers, 'get');

I don't know what goes on in that SendAjax code but that "get" looks like it should be a "post" to me

Answer 3

your GetUserRequest model should be like this

public class GetUserRequest { 
  public int pageNum {get;set;}
  public int pageSize {get;set;}
  public string sortType {get;set;}
  public string sortColumn{ get;set;}
}