Get all components in all open forms

Question

Hello,

As title says:

For Each MyForm As Form In Application.OpenForms
   For Each MyComponent As Object In MyForm.components.Components
   'components' is not a member of 'System.Windows.Forms.Form'

No idea how to loop through all components in all open forms :(

Please help

Answer 1

Try this

public IEnumerable<Component> GetComponents(Control c)
{
    FieldInfo fi = c.GetType().GetField("components", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)!;
    if (fi?.GetValue(c) is IContainer container)
    {
        return container.Components.OfType<Component>();
    }
    else
    {
        return Enumerable.Empty<Component>();
    }
}

Usage

foreach (Form form in Application.OpenForms)
{
    var componentList = GetComponents(form).ToList();
}

And for constrols where Decendant gets all controls on a form. Note the wrapper for getting all TextBoxes which can be done for other controls also.

using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace WindowsFormsLibrary.LanguageExtensions
{
    public static class FormExtensions
    {
        public static IEnumerable<T> Descendant<T>(this Control control) where T : class
        {
            foreach (Control child in control.Controls)
            {
                if (child is T thisControl)
                {
                    yield return (T)thisControl;
                }

                if (child.HasChildren)
                {
                    foreach (T descendant in Descendant<T>(child))
                    {
                        yield return descendant;
                    }
                }
            }
        }
        public static List<TextBox> TextBoxList(this Control control)
            => control.Descendants<TextBox>().ToList();
    }
}