Question

I have a panel with controls in them. Controls are buttons and progressbars. I would like to add only the buttons to a list, how can I do it?

foreach (Control item in panel1.Controls)
{
    //if (item.GetType() == typeof(ButtonControl))   //i tried this too...
    if ((item is ButtonControl) && (item.Tag.ToString() == "It's not important"))
    {                        
        panel1.BtnList.Add(item);
    }
}

Here ButtonControl is my own Control, which is inherited from Button class.

Answer 1

Using LINQ you can do for System.Windows.Forms.Button

List<Button> buttonList = panel1.Controls.OfType<Button>().ToList();

If you want to check the Tag value as well then you can do

List<Button> buttonList = panel1.Controls.OfType<Button>()
                                         .Where(r => r.Tag.ToString() == "It's not important")
                                         .ToList();

EDIT:
If ButtonControl is your own class then you can do:

 List<ButtonControl> buttonList = panel1.Controls.OfType<ButtonControl>().ToList();