Viewer Preferences
| Minimum Version | Q3 2025 |
|---|
The ViewerPreferences class designates a viewer preferences dictionary controlling the way the document is to be presented on the screen or in print. If no such dictionary is specified, viewing and printing applications should behave in accordance with their own current user preference settings.
What Are Viewer Preferences
ViewerPreferences allows you to control various aspects of how a PDF document is displayed and behaves in PDF viewer applications. These preferences affect the user interface, window behavior, and printing options when the document is opened.
The ViewerPreferences class provides the following properties:
| Property | Type | Description width | Default Value |
|---|---|---|---|
| ShouldHideToolbar | bool | Specifies whether to hide the viewer application's tool bars when the document is active. | false |
| ShouldHideMenubar | bool | Specifies whether to hide the viewer application's menu bar when the document is active. | false |
| ShouldHideWindowUI | bool | Specifies whether to hide user interface elements in the document's window (such as scroll bars and navigation controls), leaving only the document's contents displayed. | false |
| ShouldFitWindow | bool | Specifies whether to resize the document's window to fit the size of the first displayed page. | false |
| ShouldCenterWindow | bool | Specifies whether to position the document's window in the center of the screen. | false |
| ShouldDisplayDocumentTitle | bool | Specifies whether the window's title bar should display the document title from the document information dictionary. If false, displays the PDF file name instead. | false |
| NonFullScreenPageMode | NonFullScreenPageModeType | The page mode specifying how to display the document on exiting full-screen mode. Only meaningful if PageMode is FullScreen. | UseNone |
| PrintScaling | PrintScalingType | The page scaling option to be selected when a print dialog is displayed. | AppDefault |
| Duplex | DuplexType? | The paper handling option to use when printing the file from the print dialog. | null |
| NumberOfCopies | NumberOfCopiesType | The number of copies to be printed when the print dialog is opened. | One |
| Direction | DirectionType | The predominant reading order for text. Affects relative positioning of pages when displayed side by side or printed n-up. | L2R |
If a document is created with the PDF/A-1a, PDF/A-2a, PDF/A-3a, or PDF/UA-1 standard, the ShouldDisplayDocumentTitle setting is automatically set to true to comply with the standard's accessability requirements.
Example: Setting viewer preferences
You can access and modify viewer preferences through the ViewerPreferences property of the RadFixedDocument class.
RadFixedDocument document = new RadFixedDocument();
document.ViewerPreferences.ShouldHideToolbar = true;
document.ViewerPreferences.ShouldHideMenubar = true;
document.ViewerPreferences.ShouldHideWindowUI = true;
document.ViewerPreferences.ShouldFitWindow = true;
document.ViewerPreferences.ShouldCenterWindow = true;
document.ViewerPreferences.ShouldDisplayDocumentTitle = true;
document.ViewerPreferences.NonFullScreenPageMode = NonFullScreenPageModeType.UseThumbs;
document.ViewerPreferences.PrintScaling = PrintScalingType.None;
document.ViewerPreferences.Duplex = DuplexType.DuplexFlipLongEdge;
document.ViewerPreferences.NumberOfCopies = NumberOfCopiesType.Two;
document.ViewerPreferences.Direction = DirectionType.R2L;Viewer preferences are suggestions to the PDF viewer application. Not all viewers may support all preferences, and some may ignore certain settings based on their own configuration or capabilities.