Unfortunately, there is no means for this.
The default size is set as a result of the fact that you control the size of your designer control. When you increase the width and / or height of a control, the designer interprets your actions as a request to make the control a given width and / or height.
A similar situation occurs with fields. As the position of your control in the designer changes, it changes the properties to achieve the layout you created. In the case of most containers, the simplest solution is to change the fields to achieve the desired position, since you have already indicated that a solution for simple solutions is not always the most desirable.
Personally, I prefer to use only the XAML editor and only occasionally pick a peak in WPF Designer when I want to see the current layout. I also prefer to use Grid to layout most of my windows / controls, as it provides maximum flexibility not only for sizing and positioning, but also for other tasks / functions such as animations, transformations, etc.
Richard McGuire
source share