Question

I have a private function Load which creates a list, creates several objects and then binds a datagrid to the list. The code is similar to:

List<Car> cars = new List<Car>();
cars.Add(new Car("Ford", "Mustang", 1967));
cars.Add(new Car("Shelby AC", "Cobra", 1965));
cars.Add(new Car("Chevrolet", "Corvette Sting Ray", 1965));
_dgCars.DataSource = cars;

Now I would like to loop through the values in another private function. I tried something similar to:

foreach (Car car in cars) // Loop through List with foreach
{
     // Need to access individual object properties here
}

I am getting an error that cars does not exist in the current context. Is there a change I can make that will allow the List to be available globally? Perhaps I can define it elsewhere?

Answer 1

Well, this is nothing to do with lists as such. It’s general variable scope. You haven’t shown where you’ve declared the cars variable or where you’re trying to use it – but my guess is that you’ve made it a local variable, and the two snippets of code are in different methods.

You possibly want to make it an instance variable. For example:

public class Test
{
    private List<Car> cars;

    public void PopulateDataSource()
    {
        cars = new List<Car>
        {
            new Car("Ford", "Mustang", 1967),
            new Car("Shelby AC", "Cobra", 1965),
            new Car("Chevrolet", "Corvette Sting Ray", 1965)
        };
        _dgCars.DataSource = cars;
    }

    public void IterateThroughCars()
    {
        foreach (Car car in cars) // Loop through List with foreach
        {
            ...
        }
    }
}