问题
If you set OverridesDefaultStyle to true, the default style won't be used.
What is the result of using BasedOn at the same time?
<Style x:Key="MenuButton" BasedOn="{StaticResource {x:Static ToolBar.ButtonStyleKey}}"
TargetType="{x:Type c:MenuButton}">
<Setter Property="OverridesDefaultStyle" Value="True" />
</Style>
Do the two instructions contradict each other in any way?
Is it the default style underlying ToolBar.ButtonStyleKey that will be ignored?
In this particular example I don't see any difference whether OverridesDefaultStyle is true or false.
回答1:
If you were to use both of those properties, you would end up with a MenuButton object (in your example) that takes all of its Style information from your MenuButton Style and the remainder of the properties would come from your ToolBar.ButtonStyleKey Style. At least, that is true in theory, as I've never actually had to use that arrangement.
In particular, setting the OverridesDefaultStyle property to True is 'supposed' to make the styled element not use theme style properties, instead getting all of its Style values from local application styles. However, I have also found that in some instances, setting this property to True does not seem to make any difference.
On the other hand, when this property setting does work, it will remove the default ControlTemplate and so to support the same features as the default theme styles, you must supply an alternate style with a control template that replicates the same structure.
Italic text comes from the FrameworkElement.OverridesDefaultStyle Property page on MSDN
来源：https://stackoverflow.com/questions/19383347/overridesdefaultstyle-together-with-basedon-in-wpf