Navigation, zoom and search

Important

Navigation members use 1-based page numbers, matching CurrentPage and the page box in the toolbar. Annotation, text extraction and rendering members use 0-based page indexes.

Page navigation

Member	Description
CurrentPage	Current page number, 1-based. Bindable in both directions.
GoToPage(int pageNumber)	Navigates to the specified page.
NextPage(), PreviousPage()	Navigates one page forward or back.
GetPageLabel(int pageNumber)	Returns the page's label from the document, such as iv or A-2, or null when it has none. Thumbnails and the page box use labels when present.
PageChanged	Raised when the current page changes. Args include OldPage and NewPage.

Viewer.PageChanged += (_, e) =>
    StatusText = $"Page {e.NewPage} of {Viewer.PageCount}";

View modes

ViewMode selects how pages are laid out.

Value	Description
SinglePage	One page at a time. Arrow keys and swipes move between pages.
Continuous	Pages are in a vertical scrolling column. Only pages near the viewport are decoded.
TwoPages	Two pages side by side.
TwoPagesContinuous	Two pages side by side in a scrolling column.

Zoom

Member	Description
ZoomLevel	Zoom factor. 1.0 is 100%. Bindable in both directions.
ZoomMode	Manual, FitWidth, FitPage, FitHeight or ActualSize.
MinZoom, MaxZoom	Zoom bounds.
ZoomStep	Increment used by ZoomIn and ZoomOut. 0 uses the built-in adaptive step.
ZoomIn(), ZoomOut(), ResetZoom()	Adjusts the zoom.
FitWidth(), FitPage(), FitHeight()	Applies a fit mode to the zoom.
ZoomChanged	Raised when the zoom level changes.

Gestures

On touch devices and trackpads, the control handles the following gestures:

• Pinch to zoom
• Swipe between pages (in SinglePage and TwoPages view modes)
• Long press for contextual menu

Outlines and links

GetOutline() returns the document's table of contents as a tree of PdfBookmark items, each with a Title, optional PageIndex, Children and optional Destination. The sidebar shows it in the Table of Contents tab when IsTableOfContentsEnabled is true. HasOutline reports whether the document has one.

Member	Description
GetOutline()	Returns the document's table of contents.
GoToBookmark(PdfBookmark)	Navigates to an outline entry. This is its destination (page plus position) when it has one, else its page.
NavigateTo(PdfLinkDestination)	Navigates to a page destination, including its position and zoom if specified by the destination. Returns false for URI and file destinations.

Links

Links in the document are clickable. When clicking a link, LinkClicked is raised. The target isDestination, which is a PdfLinkDestination.PageDestination, UriDestination or FileDestination.

Unless a handler sets Handled to true:

• A page destination navigates within the document.
• An http, https or mailto URI opens in the system browser or mail client after the user confirms.
• File destinations and other URI schemes are raised but never opened by the viewer.

Viewer.LinkClicked += (_, e) =>
{
    if (e.Destination is PdfLinkDestination.UriDestination uri
        && uri.Uri.StartsWith("myapp:"))
    {
        e.Handled = true;
        HandleDeepLink(uri.Uri);
    }
};

Bookmarks

User bookmarks are separate from the document outline. They are stored in the PDF itself. The sidebar lists them in the Bookmarks tab when IsBookmarksEnabled is true.

ShowBookmarkIndicators draws a ribbon on bookmarked pages and thumbnails.

Bookmark changes are written by save and are not part of the undo history.

Member	Description
IsPageBookmarked(int pageNumber)	Whether the specified page is bookmarked.
AddBookmark(int pageNumber), RemoveBookmark(int pageNumber), ToggleBookmark(int pageNumber)	Changes the bookmark status of a page. Returns whether anything changed.
ToggleBookmarkCurrentPage()	Toggles the bookmark on the current page.
HasBookmarks	Whether the document has any user bookmarks.
BookmarksChanged	Raised after any change.

Search

Each individual PdfSearchResult has a PageIndex, CharIndex and CharCount of the match, and its Bounds on the page.

Member	Description
SearchAsync(string query, SearchOptions? options = null)	Searches the document. Returns the matches and highlights them on the pages.
SearchAsync(string query, SearchOptions? options, CancellationToken)	Searches the document, with the option to cancel. A cancelled search stops within a page. Returns the matches up till cancellation and highlights them on the pages.
FindNext(), FindPrevious()	Moves the active match.
ClearSearch()	Clears the matches and their highlights.
SearchResults	Matches of a search.
SearchResultCount	Number of matches.
CurrentSearchResultIndex	Index of the active match.
SearchCompleted	Raised when a search finishes.

Search options

The following SearchOptions are available. The toolbar search box is bound to SearchQuery, SearchMatchCase and SearchMatchWholeWord.

• MatchCase: Search matches uppercase/lowercase.
• MatchWholeWord: Search matches whole words.
• StartPage: A 0-based page index.
• MaxResults: Set 0 for unlimited results.

var results = await Viewer.SearchAsync("invoice", new SearchOptions
{
    MatchCase = false,
    MatchWholeWord = true,
});

Console.WriteLine($"{results.Count} matches");
Viewer.FindNext();

Text selection

Text selection cannot span pages. Setting AllowTextSelection to false disables selection entirely.

Selecting text shows a contextual menu with Copy and the text markup tools. See Annotations.

Member	Description
SelectAll()	Selects all text on the current page.
ClearSelection()	Clears the selection.
GetSelectedText()	Returns the selected text.
CopySelectionToClipboard()	Copies the selection to the clipboard.
HasSelection, SelectedText	Current selection state.

Text extraction and page images

These members take 0-based page indexes.

Member	Description
GetPageTextAsync(int pageIndex, CancellationToken)	Extracts the plain text of the specified page. Returns an empty string when no document is loaded or the index is out of range.
GetTextAsync(CancellationToken)	Extracts the whole document's text, one string per page.
RenderPageToImageAsync(int pageIndex, double scale = 1.0, CancellationToken)	Renders the specified page to a Bitmap at the given scale, where 1.0 is 100%. Returns null when no document is loaded or the index is out of range.

// Create a thumbnail of the first page for a file list
using var thumbnail = await Viewer.RenderPageToImageAsync(0, scale: 0.25);

tip

Dispose the bitmap after running RenderPageToImageAsync.

Keyboard shortcuts

Most shortcuts are enabled only when EnableKeyboardShortcuts is true. Set to false to keep these keystrokes for your own commands. Similarly, combinations not used by PdfViewer, such as Ctrl+Shift+A, can be used by your own handlers.

See Always on for exceptions that are unaffected by EnableKeyboardShortcuts.

Shortcuts in the tables below are listed with the Ctrl key. Unless otherwise specified, this can be directly substituted with Cmd on macOS.

Shortcut	Action	Notes
Ctrl+C	Copy the selected text or annotation.	Only handled when something is selected.
Ctrl+V	Paste the copied annotation onto the current page.	Needs a copied annotation and CanEditAnnotations.
Ctrl+A	Select all text on the current page.
Ctrl++	Zoom in	Alternatives are = and the numeric keypad +.
Ctrl+-	Zoom out	Alternatives are _ and the numeric keypad -.
Ctrl+0	Adjust zoom to actual size (100%).
Ctrl+1	Adjust zoom to fit page.
Ctrl+2	Adjust zoom to fit width.
Ctrl+D	Bookmark the current page.	Add only. Does not remove.
Ctrl+Z	Undo
Windows: Ctrl+Y, macOS: Cmd+Shift+Z	Redo
Ctrl+S	Save to Source.	Only when the document can be saved. Otherwise left to the host.
Delete, Backspace	Delete the selected annotation.	Needs CanEditAnnotations. Undoable.
Arrow keys	Nudge the selected annotation by 1 px.	Can be disabled with IsArrowKeyNudgeEnabled.
Shift + arrow keys	Nudge the selected annotation by 10 px.	Can be disabled with IsArrowKeyNudgeEnabled.
↑, ↓	Scroll in the continuous view modes.
← / ↑, → / ↓	Previous / next page in single and two-page view modes.

Always on

These keyboard shortcuts are always enabled and cannot be disabled by setting EnableKeyboardShortcuts to false.

Shortcut	Action
Esc	Closes the contextual menu, clears the annotation or text selection, deactivates the active tool. Only marked handled when something changed.
Esc in a form field	Leaves form focus.
Tab / Shift+Tab in the viewer	Enters the first / last form field on the current page.
Tab / Shift+Tab in a form field	Next / previous form field. Leaves the viewer when there is no next field.
Ctrl+A in a form field	Select all text in the form field.
Ctrl+C in a form field	Copy text in the form field.
Ctrl+X in a form field	Cut text in the form field.
Ctrl+V in a form field	Paste text into the form field.
Ctrl+Z in a form field	Undo inside the form field.
Windows: Ctrl+Y, macOS: Cmd+Shift+Z in a form field	Redo inside the form field.

Inside the PDF viewer's chrome

FocusViewer() moves keyboard focus to the viewer so the shortcuts apply.

Where	Shortcut	Action
Inline text editor (text box or shape text)	Esc	Cancel
	Ctrl+Enter	Commit
Search box	Enter	Next result
	Esc	Clear and close
Page number box	Enter	Commit
	Esc	Revert
Link URL dialog, password, go-to-page, custom zoom overlays	Enter	Commit
	Esc	Cancel
Hex color input	Enter	Apply color

See also

• PdfViewer control
• Annotations
• Platforms and performance