RenderPageThumbnail - TPdf - PDFium Delphi Component

Component: TPdf · Unit: PDFium

Renders any one-based page into a bitmap that fits within the requested thumbnail bounds

Syntax

function RenderPageThumbnail(PageIndex, MaxWidth, MaxHeight: Integer): TBitmap;

function RenderPageThumbnail(PageIndex, MaxWidth, MaxHeight: Integer; Rotation: TRotation; Options: TRenderOptions; Background: TColor; const ColorScheme: TPdfColorScheme): TBitmap;

Parameters

PageIndex	`Integer` - One-based page index to render
MaxWidth	`Integer` - Maximum thumbnail width in pixels
MaxHeight	`Integer` - Maximum thumbnail height in pixels
Rotation	`TRotation` - Additional clockwise render rotation
Options	`TRenderOptions` - Native PDFium render flags included in the cache key
Background	`TColor` - Bitmap background colour
ColorScheme	`TPdfColorScheme` - Optional low-vision path and text colour overrides

Return Value

A caller-owned TBitmap, or nil when the document is inactive, the page index is invalid, or the requested size is not positive

Description

The short overload preserves the page aspect ratio and renders on a white background, while the full overload controls rotation, flags, background, and low-vision colours

Both overloads reuse deep internal bitmap copies through the unified thumbnail LRU and return a distinct caller-owned TBitmap on every call

It does not change PageNumber, replace the current loaded page, or fire page-change notifications

Remarks

API names, type names, file names, and PDF terms keep their original spelling so code search remains reliable
Use this for thumbnail strips or navigation panels that must not disturb the editing state of the main TPdf instance

Example

Bmp := Pdf1.RenderPageThumbnail(3, 180, 240);
try
  if Bmp <> nil then
    Image1.Picture.Assign(Bmp);
finally
  Bmp.Free;
end;

RenderPageThumbnail method