c# - How to count the number of elements that match a condition with LINQ

Question

I've tried a lot of things but the most logical one for me seems this one:

int divisor = AllMyControls.Take(p => p.IsActiveUserControlChecked).Count();

AllMyControls is a Collection of UserControls, what I want to know is how many UserControls have the IsActiveUserControlChecked property set to true.

What I get in VS is:

Cannot convert lambda expression to type 'int' because it is not a delegate type

What's wrong with my expression?

Answer 1

int divisor = AllMyControls.Where(p => p.IsActiveUserControlChecked).Count()

or simply

int divisor = AllMyControls.Count(p => p.IsActiveUserControlChecked);

Since you are a beginner, it would be worthwhile to take a look at Enumerable documentation