How To Determine When a Page Is Done Printing in WebBrowser Control

SUMMARY
The printing from a WebBrowser control can be customized by using custom headers and footers ( http://support.microsoft.com/kb/267240) or replacing the default print template. However, using such techniques conflicts with the PRINT_WAITFORCOMPLETION flag, which is used for synchronous printing.

Since Internet Explorer 6.0, the WebBrowser control raises the DWebBrowserEvents2::PrintTemplateTeardown event when a print template has been destroyed. If the printing involves a custom print template, this is a good indicator of print completion. You can create a event handler function in your application for this event to determin if a the WebBrowser control is finished printing a Web page.

MORE INFORMATION

The WebBrowser control launches another thread which hosts another MSHTML document which renders to the printer. When this thread is finished, if a custom print template is involved, the WebBrowser control destroys the print template and raises PrintTemplateTeardown event. This indicates that the WebBrowser control has completed printing the Web page.

If the default print template and the customization of headers and footers are desired, load the template from the source of IExplorer.exe, and use it as a custom template.

To translate the asynchronous printing to synchronous, a message loop need to be created (better if use with a timeout handler) .

BOOL PrintTemplateTeardownFired=FALSE;
//launch printing......
//loop until PrintTemplateTeardown is set to TRUE in the PrintTemplateTeardown event handler
MSG msg;
while (!PrintTemplateTeardownFired&&GetMessage(&msg, NULL, 0, 0) > 0)
{
  TranslateMessage(&msg);
  DispatchMessage(&msg);
}

Reference

• PrintTemplateTeardown Event(http://msdn.microsoft.com/library/default.asp?url=/workshop/browser/webbrowser/reference/events/printtemplateteardown.asp)
• How To Determine When a Page Is Done Loading in WebBrowser Control(http://support.microsoft.com/kb/180366)
• How To Handle Document Events in a Visual Basic .NET Application (http://support.microsoft.com/kb/311284)