If you choose to create a customized toolbar (for an example, see the Customizing the Toolbar topic), you may need to hide the default toolbar available in the C1PdfViewer control. You can hide the built-in toolbar using the ToolbarVisibility property. For example:
•XAML
<c1:C1PdfViewer x:Name="C1PdfViewer1" ToolbarVisibility="Collapsed"/>
Me.C1PdfViewer.ToolbarVisibility = Visibility.Collapsed
•C#
this.C1PdfViewer.ToolbarVisibility = Visibility.Collapsed;