WinForms: How to find all BindingSources in an UserControl

Question

In the program we are working on, the user data is collected in UserControls which is data bound to a business entity using BindingSources.

I need to find all the BindingSources in a UserControl programatically.

Since a BindingSource source is not added to the UserControl's Controls collection, I cannot search in there.

Can this be done?

Answer 1

The biggest problem was to find a solution for my method to be available for all the UserControls and still be able to use the WinForms designer from Visual Studio.

Because I don't know any way of using the designer on a class that does not derive from UserControl, I have made an interface without any methods, IBusinessEntityEditorView, and an extension method that takes such a view, uses reflection to find the components field in which I search for my BindingSources:

public interface IBusinessEntityEditorViewBase
{
}

...

public static void EndEditOnBindingSources(this IBusinessEntityEditorViewBase view)
{
    UserControl userControl = view as UserControl;
    if (userControl == null) return;

    FieldInfo fi = userControl.GetType().GetField("components", BindingFlags.NonPublic | BindingFlags.Instance);
    if (fi != null)
    {
        object components = fi.GetValue(userControl);
        if (components != null)
        {
            IContainer container = components as IContainer;
            if (container != null)
            {
                foreach (var bindingSource in container.Components.OfType<BindingSource>())
                {
                    bindingSource.EndEdit();
                }
            }
        }
    }
}