Hi,
Thank you for your inquiry.
Are you using PdfViewer Control? If so, I suggest you use PdfDocumentViewer Control, due to the PdfViewer Control is an integral control, you can’t customize the internal logic, however, you can customize PdfDocumentViewer Control according to your requirements.
For your first question, I don't quite understand what you mean. Our product doesn’t have a method to directly unload PDF file that have already been loaded in the control, but you can customize a button to load a blank PDF file.
For the second question, you can achieve your needs without adding the open button during the process of customizing the PdfDocumentViewer control. Regarding how to use the PDFDocumentViewer control function, I have attached a Word file that records the implementation steps for your reference. If you have any issue just feel free to contact us.
Step.zip
Sincerely,
Ula
E-iceblue support team
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