[C#]获得WindowsForm上所有特定类型的控件

public static class Utils
{
    public static IEnumerable<TControl> GetChildControls<TControl>(this Control control) where TControl : Control
    {
        if (control.Controls.Count == 0)
        {
            return Enumerable.Empty<TControl>();
        }
        var children = control.Controls.OfType<Control>().ToList();
        return children.OfType<TControl>().Concat(children.SelectMany(n => n.GetChildControls<TControl>()));
    }
}