How to open PDF document from URL path using PDF viewer for WinRT

// Create an instance of HttpClient

 HttpClient httpClient = new HttpClient();

// Get the PDF document in byte array

Byte[] contentBytes = await httpClient.GetByteArrayAsync("Your PDF link");

// Load the Byte array

PdfLoadedDocument loadedDocument = new PdfLoadedDocument(contentBytes);

// Display the PDF document in PdfViewer

pdfViewer.LoadDocument(loadedDocument);