Styling the indeterminate state of a WPF checkbox

Question

I want to style the indeterminate state of a WPF checkbox. We have a treeview control with checkboxes, and we want the indeterminate state to represent that some descendants are

Answer 1

Have you thought about using SimpleStyles as the base for control?

By selecting this control from the Assets panel, Expression Blend will place a new resource dictonary in your project that you can use to modify the style as you please. Might be a better starting point than trying to hack into the Chrome for the standard checkbox.