C# .NET - Save Invoice to PDF in QuickBooks use Windows SDK

I am need to create the  winform for download invoices from QuickBooks  save as pdf file. Can you pls help me is it possible in windows sdk.

No, not natively.  You'll have to grab your data and create your own PDFs using something like Aspose PDF.

Some PDF software lets you register it as a printer type.  If the SDK supports "send to printer" for the invoices, you could try that.  Instead of printing the document, the PDF software would be launched.

Unlike PNG and JPEG, Windows doesn't natively support PDF format so you'll need to use a library if you want to create a new PDF.

There are many a wide variety of libraries you can choose from like Haru, leadtools, etc.

I found the following links that might be of help to you:

http://www.codeproject.com/Articles/28050/Generate-PDF-Using-C

https://social.msdn.microsoft.com/Forums/vstudio/en-US/4a13a735-633c-445e-b633-268d96293170/create-pdf-file-from-cnet?forum=netfxbcl