Resize a WPF window, but maintain proportions?

Question

I have a user resizable WPF Window that I want to constrain the resizing so the aspect ratio of the window stays constant.

Ideally I would like to constrain mouse

Answer 1

Does that do the trick:

protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo) {

    if (sizeInfo.WidthChanged) this.Width = sizeInfo.NewSize.Height * aspect;
    else this.Height = sizeInfo.NewSize.Width / aspect;
}

Found it here.