NOTE

Syncfusion recommends using Blazor PDF Viewer (NextGen) Component which provides fast rendering of pages and improved performance. Also, there is no need of external Web service for processing the files and ease out the deployment complexity. It can be used in Blazor Server, WASM and MAUI applications without any changes.

Events in Blazor PDF Viewer Component

5 Sep 20238 minutes to read

The events provided in PDF Viewer component are listed out as follows:

Name	Description
AddSignature	Triggers when signature is added over the page of the PDF document.
AjaxRequestFailed	Triggers when the AJAX request is failed.
AnnotationAdded	Triggers when an annotation is added over the page of the PDF document.
AnnotationMouseover	Triggers when mouse over the annotation object.
AnnotationMoved	Triggers when an annotation is moved over the page of the PDF document.
AnnotationPropertiesChanged	Triggers when the property of the annotation is changed in the page of the PDF document.
AnnotationRemoved	Triggers when an annotation is removed from the page of the PDF document.
AnnotationResized	Triggers when an annotation is resized over the page of the PDF document.
AnnotationSelected	Triggers when an annotation is selected over the page of the PDF document.
AnnotationUnselected	Triggers when an annotation is unselected over the page of the PDF document.
Created	Triggers when the PDFViewer component is created.
DocumentLoaded	Triggers while loading document into PdfViewer.
DocumentLoadFailed	Triggers while loading document got failed in PdfViewer.
DcoumentUnloaded	Triggers while close the document
DownloadEnd	Triggers an event when the download actions is finished.
DownloadStart	Triggers an event when the download action is started.
ExportFailed	Triggers when an export annotations failed in the PDF Viewer.
ExportStarted	Triggers when an exported annotations started in the PDF Viewer.
ExportSucceed	Triggers when an export annotations succeed in the PDF Viewer.
ExtractTextCompleted	Triggers when an text extraction is completed in the PDF Viewer.
ImportFailed	Triggers when an imports annotations failed in the PDF document.
ImportStarted	Triggers when an imported annotations started in the PDF document.
ImportSucceed	Triggers when an imports annotations succeed in the PDF document.
MoveSignature	Triggers when an signature is moved over the page of the PDF document.
OnAnnotationDoubleClick	Triggers an event when the annotation is double click.
OnHyperlinkClick	Triggers when hyperlink in the PDF Document is clicked
OnHyperlinkMouseOver	Triggers when hyperlink in the PDF Document is hovered
OnPageClick	Triggers when the mouse click is performed over the page of the PDF document.
OnTextSearchComplete	Triggers an event when the text search is completed.
OnTextSearchHighlight	Triggers an event when the text search text is highlighted.
OnTextSearchStart	Triggers an event when the text search is started.
OnTextSelectionEnd	Triggers an event when the text selection is finished.
OnTextSelectionStart	Triggers an event when the text selection is started.
OnThumbnailClick	Triggers an event when the thumbnail is clicked in the thumbnail panel of PDF Viewer.
PageChanged	Triggers when there is change in current page number.
PageMouseover	Triggers when mouse over the page.
PrintEnd	Triggers an event when the print actions is finished.
PrintStart	Triggers an event when the print action is started.
RemoveSignature	Triggers when signature is removed over the page of the PDF document.
ResizeSignature	Triggers when signature is resized over the page of the PDF document.
SignaturePropertiesChange	Triggers when the property of the signature is changed in the page of the PDF document.
SignatureSelected	Triggers when signature is selected over the page of the PDF document.
SignatureUnselected	Triggers when signature is unselected over the page of the PDF document.
ZoomChanged	Triggers when there is change in the magnification value.

Adding PDF Viewer events to Blazor component

The Syncfusion PDF Viewer events has to be wrapped inside the PdfViewerEvents tag.

<SfPdfViewerServer DocumentPath="@DocumentPath" Height="500px" Width="1060px" >
    <PdfViewerEvents DocumentLoaded="@DocumentLoaded"></PdfViewerEvents>
</SfPdfViewerServer>

@code{
    private string DocumentPath { get; set; } = "wwwroot/Data/PDF_Succinctly.pdf";
    private void DocumentLoaded(LoadEventArgs args)
    {
        object PageData = args.PageData;
    }
}

Created event

The Created event is triggered when the PDFViewer component is rendered.

The following code illustrates how to load PDF document on created event.

@using Syncfusion.Blazor.PdfViewerServer
@using Syncfusion.Blazor.PdfViewer

<SfPdfViewerServer DocumentPath="@DocumentPath" Width="560" Height="315">
    <PdfViewerEvents Created="created"></PdfViewerEvents>
</SfPdfViewerServer>

@code 
{
    public string DocumentPath { get; set; }

    //Triggers when the PDFViewer component is created.
    public void created()
    {
        string Link = "http://infolab.stanford.edu/pub/papers/google.pdf";
        System.Net.WebClient webClient = new System.Net.WebClient();
        //Returns the byte array containing the downloaded PDF file.
        byte[] byteArray = webClient.DownloadData(Link);
        //Converting the byte array to Base64 string and sets the document path.
        DocumentPath = "data:application/pdf;base64," + Convert.ToBase64String(byteArray);
    }  
}

NOTE

View sample in GitHub.

NOTE

You can refer to the Blazor PDF Viewer feature tour page for its groundbreaking feature representations. You can also explore the Blazor PDF Viewer example to understand how to explain core features of PDF Viewer.