How does the WinRT Chrome app print without triggering the OS's "Print" dialog?
From what I've seen elsewhere, every WinRT app must go through the Windows Print dialog to print. But when you print a page from the Chrome Metro app, you get the Chrome Print dialog, and the Windows Print dialog is not triggered.
I don't think you can. The one browser app that enjoys the privilege of being your WinRT browser also enjoys special privileges not granted to other WinRT apps. For example, you can bet that Chrome is neither a XAML app nor an HTML/JS app. Yet all WinRT apps (except the one browser app) must be one of these two.
Skipping the print dialog is probably a matter a simply calling the underlying Win32 print APIs -- something browsers are allowed to do but no other WinRT app is.
来源：https://stackoverflow.com/questions/18540605/how-does-the-winrt-chrome-app-print-without-triggering-the-oss-print-dialog