/// <summary>
/// This takes the PrintWorkflowForegroundSetupRequestedEventArgs and gets the IPrinterExtensionContextNative from it,
/// via the PrintWorkflowConfiguration property.
/// </summary>
/// <param name="args">IActivatedEventArgs passed to OnActivated()</param>
/// <returns>Pointer to interface as IntPtr</returns>
private static IntPtr GetPrintWorkflowConfigurationNativeAsIntPtr(PrintWorkflowForegroundSetupRequestedEventArgs args)
{
Object printerExtensionContextNative = args.Configuration;
IntPtr ptr = IntPtr.Zero;
Guid iidIPrinterExtensionContextNative = new Guid("C056BE0A-9EE2-450A-9823-964F0006F2BB");
int hr = Marshal.QueryInterface(Marshal.GetIUnknownForObject(printerExtensionContextNative), ref iidIPrinterExtensionContextNative, out ptr);
if (hr < 0)
{
throw new InvalidCastException(iidIPrinterExtensionContextNative.ToString());
}
if (ptr != IntPtr.Zero)
{
// This is good
}
else
{
throw new InvalidCastException(iidIPrinterExtensionContextNative.ToString());
}
return(ptr);
}
/// <summary>
/// Handle the Print Task Setup Event
/// </summary>
/// <param name="sessionManager">Session manager</param>
/// <param name="printTaskSetupArgs">Has the Configuration and Controller</param>
internal void OnSetupRequested(PrintWorkflowForegroundSession sessionManager, PrintWorkflowForegroundSetupRequestedEventArgs printTaskSetupArgs)
{
// If anything asynchronous is going to be done, you need to take out a deferral here,
// since otherwise the next callback happens once this one exits, which may be premature
Deferral setupRequestedDeferral = printTaskSetupArgs.GetDeferral();
// Get information about the source application, print job title, and session ID
string sourceApplicationName = printTaskSetupArgs.Configuration.SourceAppDisplayName;
string jobTitle = printTaskSetupArgs.Configuration.JobTitle;
string sessionId = printTaskSetupArgs.Configuration.SessionId;
string localStorageVariablePrefix = string.Format("{0}::", sessionId);
localStorage.SetStorageKeyPrefix(localStorageVariablePrefix);
// Get the PrinterExtensionContextNative from the activation arguments
IntPtr ptr = GetPrintWorkflowConfigurationNativeAsIntPtr(printTaskSetupArgs);
// Create the Print Helper
PrintHelperClass printHelper = new PrintHelperClass(InitializationType.PrinterExtensionContextNativeType, (ulong)ptr);
printerName = printHelper.GetPrinterName();
WorkflowHeadingLabel = string.Format(workflowHeadingFormat, sourceApplicationName, printerName);
// Add callback handler on main page
try
{
printHelper.OnInkLevelReceived += OnQueryResultReceived;
// Send the BiDi query
printHelper.SendInkLevelQuery();
}
catch (Exception ex)
{
string errorMessage = ex.Message;
Debug.WriteLine(errorMessage);
}
finally
{
// Complete the deferral taken out at the start of OnSetupRequested
setupRequestedDeferral.Complete();
}
}