Change WPF DocumentViewer viewing mode

Hello I've got the problem that when I just add a <DocumentViewer x:Name="docViewer" /> I get a toolbar what allow me to change the viewing mode of the XPS document like here: enter image description here

But how can I do this programmatically? I cant find any property that do this and the MSDN and Google say nothing about this feature. Then I found the FlowDocumentReader control what have a ViewingMode property, however it can't display a XPS document. I can't believe that it is not possible to do this, I mean that function is available by default, I just want to change it programmatically...

Solution

DocuementViewer didn't exposed any property to change the ViewMode. But in case you want to change the ViewMode programmatically, you can execute the commands exposed by DocumentViewer which are as -

DocumentViewer.FitToWidthCommand
DocumentViewer.FitToHeightCommand
DocumentViewer.FitToMaxPagesAcrossCommand

You can bind these commands to your custom button or programmatically you can change the ViewMode. Suppose you have a DocuementViewer named documentViewer, you can call these methods on this instance like this -

documentViewer.FitToWidth()
documentViewer.FitToHeight()
documentViewer.FitToMaxPagesAcross()