如何使用params关键字读取参数并实现函数

Question

Hi I have here a code snippet. This isn't mine, I saw this in the internet while learning on how to deal with Entity Framework I know it just including (eager load) the navigation properties then return it as IQueryable

What I want to know is:

1. How do you read this parameter params System.Linq.Expressions.Expression<Func<T, object>>[] includeProperties ?

2. How do you call or use this function? (Should pass collection, am I right? A little example would be a great help since I learn in a way when I see some demo)

    public IQueryable<Customer> AllIncluding(params System.Linq.Expressions.Expression<Func<T, object>>[] includeProperties) { var query = context.Customers; foreach (var includeProperty in includeProperties) { query = query.Include(includeProperty); } return query; } 

Any help would be much appreciated. Thanks!

Answer 1

params lets you pass an array parameter as an actual array or an open-ended list of values:

var includes = new Expression<Func<Customer, object>>[] 
    { 
        i => i.SubProperty1, 
        i => i.SubProperty2
    };
var query = db.Entities.AllIncluding(includes);

or just

var query = db.Entities.AllIncluding(i => i.SubProperty1, i => i.SubProperty2);

I'm guessing on the specific types and properties, but hopefully you get the idea.