C# 在不使用控制事件的情况下失去焦点

Question

There is a way to get who lost his focus in a c# form without using the LostFocus event each component?

[edit]

I need for a On Screen Keyboard.

I need to store last focussed control to fire keypress, but i need to do it to all in the window.

Also the main project is wpf, than i have some component nested as itemsTemplate and so on...

Answer 1

I finally used this:

    foreach (Control uie in FindInLogicalTreeDown(this, typeof(TextBox))) AssignEvents(uie);

    private static IEnumerable<DependencyObject> FindInLogicalTreeDown(DependencyObject obj, Type type)
    {
        if (obj != null)
        {
            if (obj.GetType() == type) { yield return obj; }
            foreach (object child in LogicalTreeHelper.GetChildren(obj)) 
                if (typeof(DependencyObject).IsAssignableFrom(child.GetType()))
                    foreach (var nobj in FindInLogicalTreeDown((DependencyObject)child, type)) yield return nobj;
        }
        yield break;
    }

    void AssignEvents(Control element)
    {
        element.GotMouseCapture += new MouseEventHandler(Component_GotFocus);
    }

    public Control LastFocus { get; set; }
    public void Component_GotFocus(object sender, RoutedEventArgs e)
    {
        LastFocus = (Control)sender;
        if (LastFocus.GetType() == typeof(TextBox)) { KeyboardVisible = true; }
    }

Answer 2

i don't think there is any way until unless you subscribe events and keep track which lost focus event has fired last