Creating SfPdfViewerServer by RenderFragment and getting reference by AddComponentReferenceCapture

Question

public SfPdfViewerServer PdfViewer { get; set; } // reference for pdf viewer

protected RenderFragment RenderComponentHandler { get; set; } // renderer

protected RenderFragment CreatePdfComponent() => builder =>

{

builder.OpenComponent(0);

builder.AddComponentReferenceCapture(1, (inst) => { PdfViewer = inst as SfPdfViewerServer; }); // capturing reference here

builder.AddAttribute(2, "Height", "590px");

builder.AddAttribute(3, "DocumentPath", pdfPath);

builder.CloseComponent();

};

after running the code below , PdfViewer is always null. I could not understand why ?

RenderComponentHandler = CreatePdfComponent();

PdfViewer  is always null. I could not understand why ? RenderComponentHandler = CreatePdfComponent();

Visvesvar Venkatesan · Accepted Answer

From your sample, we thought that you have try to set the
DocumentPath after creating the component. Your component instance will be set
after the component is rendered on the UI. So please use the created event to
set the DocumentPath.    public void OnCreated()    {       
_viewer.DocumentPath = pdfPath;    }    RenderFragment DrawCounter()    {       
return new RenderFragment(builder =>       
{           
builder.OpenComponent(0, typeof(SfPdfViewerServer));           
builder.AddAttribute(1, "Height", "590px");           
//builder.AddAttribute(2,
"DocumentPath", pdfPath);             builder.AddAttribute(3, "ChildContent", (RenderFragment)((builder2) =>                  
{                      
builder2.OpenComponent(4, typeof(PdfViewerEvents));                      
builder2.AddAttribute(5, "Created", Microsoft.AspNetCore.Components.EventCallback.Factory.Create<object>(this, OnCreated));                      
builder2.CloseComponent();                  
}));           
builder.AddComponentReferenceCapture(6, inst => { _viewer = (SfPdfViewerServer)inst; });           
builder.CloseComponent();          });    }Please find the sample also: https://www.syncfusion.com/downloads/support/directtrac/general/ze/179045~1-1709857762.zip

Visvesvar Venkatesan · Answer

We have provided a code snippet and sample for getting a
reference in component reference capture.Code snippet:private SfPdfViewerServer _viewer = null;    private string pdfPath { get; set; } = "wwwroot/PDF_Succinctly.pdf";    public void Onclick()    {       
    }    RenderFragment DrawCounter()    {       
return new RenderFragment(builder =>       
{           
builder.OpenComponent(0, typeof(SfPdfViewerServer));           
builder.AddAttribute(1, "Height", "590px");           
builder.AddAttribute(2, "DocumentPath", pdfPath);           
builder.AddComponentReferenceCapture(3, inst => { _viewer = (SfPdfViewerServer)inst; });           
builder.CloseComponent();       
});    }Sample - https://www.syncfusion.com/downloads/support/directtrac/general/ze/componentreferencecapture-1008192453.zipKindly revert to us if you still have any other queries.

Emre Misirlioglu · Answer

I have prepared a small project which will show my problem.

Emre Misirlioglu · Answer

I have prepared a small project which will show my problem.

Emre Misirlioglu · Answer

have prepared a small project which will show my problem.

Attachment: QMS_139ba2a7.rar

Emre Misirlioglu · Answer

Thank you very much.