how loop through multiple checkbox in C#

Question

I have 100 checkbox in a winfrom. Their name is sequential like checkbox1,checkbox2 etc. I have a submit button in my winform. After clicking the submitting button, it check

Answer 1

There is LINQ method OfType. Why not use it to get rid of manual type testing and casting?

foreach (var ctrl in panel.Controls.OfType().Where(x => x.IsChecked)
{
    // ....
}