By default, the WinForms Document Viewer creates document pages in the Application.Idle
event. Users may access document pages as soon as pages are ready. The progress bar down below the viewer indicates a document generation progress. Users can stop document generation if required.
You may wish to enable the DocumentViewer.UseAsyncDocumentCreation option and enhance user experience while previewing, exporting, and printing reports. For more information, refer to the following article: How to create a report in a separate thread.