912554: Added notes for not use the setState method in the onPageChanged callback.

lingeshwaran-sf4984 · lingeshwaran-sf4984 · commit d0a5793d1a29 · 2026-07-16T15:50:40.000+05:30
diff --git a/Document-Processing/PDF/PDF-Viewer/flutter/page-navigation.md b/Document-Processing/PDF/PDF-Viewer/flutter/page-navigation.md
@@ -234,4 +234,6 @@ Widget build(BuildContext context) {
 }
 
 {% endhighlight %}
-{% endtabs %}
+{% endtabs %}
+
+N> Avoid calling `setState()` inside the `onPageChanged` or `onDocumentLoaded` callbacks. Doing so rebuilds the entire widget tree — including the `SfPdfViewer` — which can decrease performance when viewing large PDF documents. Instead, use an `addListener()` to the `PdfViewerController` to monitor page changes and update only the specific UI elements that need to change (for example, the page number indicator). This keeps viewer rebuilds to a minimum and delivers smoother scrolling and better stability with large PDF files.

Original file line number	Diff line number	Diff line change
`@@ -234,4 +234,6 @@ Widget build(BuildContext context) {`
`234`	`234`	`}`
`235`	`235`
`236`	`236`	`{% endhighlight %}`
`237`		`-{% endtabs %}`
	`237`	`+{% endtabs %}`
	`238`	`+`
	`239`	+N> Avoid calling `setState()` inside the `onPageChanged` or `onDocumentLoaded` callbacks. Doing so rebuilds the entire widget tree — including the `SfPdfViewer` — which can decrease performance when viewing large PDF documents. Instead, use an `addListener()` to the `PdfViewerController` to monitor page changes and update only the specific UI elements that need to change (for example, the page number indicator). This keeps viewer rebuilds to a minimum and delivers smoother scrolling and better stability with large PDF files.