How to keep a nested grid square without using ViewBox?

This is similar to how-do-i-keep-aspect-ratio-on-scalable-scrollable-content-in-wpf, with the following differences:

1. I'd like to avoid side-effects of the ViewBox - while the grid should resize when the container resizes, some of the grid content should keep their sizes (buttons for example)开发者_如何学Go.
2. I don't need aspect ratios other than 1:1 (maybe some binding tricks can be used?)
3. Code behind is Ok, though if possible I'd like to avoid creating yet another container

You just need to bind one of the parameters Width or Height to the other:

<Image x:Name="image" Height="{Binding Width, ElementName=image}"/>

You should bind Grid's Width and Height to one value:

<!--Dont forget to specify source where MaxSizeParam lies-->
<Grid Width="{Binding MaxSizeParam}" Height="{Binding MaxSizeParam}"/>

MaxSizeParam you can provide wherever you want an in what manner you want. For example if grid has Button then on SizeChanged event of Button you should recalculate MaxSizeParam:

void button_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            MaxSizeParam = e.NewSize.Width > e.NewSize.Height ? e.NewSize.Width : e.NewSize.Height;
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("MaxSizeParam"));
        }