/// <summary>
/// Sends a ink status query to the selected printer.
/// </summary>
/// <param name="sender" type = "Windows.UI.Xaml.Controls.Button">A pointer to the button that the user hit to enumerate printers</param>
/// <param name="e">Arguments passed in by the event.</param>
void GetInkStatus(object sender, RoutedEventArgs e)
{
if (AssociatedPrinters.Items.Count > 0)
{
// Get the printer that the user has selected to query.
ComboBoxItem selectedItem = AssociatedPrinters.SelectedItem as ComboBoxItem;
// The interfaceId is retrieved from the detail field.
string interfaceId = selectedItem.DataContext as string;
try
{
// Unsubscribe existing ink level event handler, if any.
if (printHelper != null)
{
printHelper.OnInkLevelReceived -= OnInkLevelReceived;
printHelper = null;
}
object context = Windows.Devices.Printers.Extensions.PrintExtensionContext.FromDeviceId(interfaceId);
// Use the PrinterHelperClass to retrieve the bidi data and display it.
printHelper = new PrintHelperClass(context);
try
{
printHelper.OnInkLevelReceived += OnInkLevelReceived;
printHelper.SendInkLevelQuery();
rootPage.NotifyUser("Ink level query successful", NotifyType.StatusMessage);
}
catch (Exception)
{
rootPage.NotifyUser("Ink level query unsuccessful", NotifyType.ErrorMessage);
}
}
catch (Exception)
{
rootPage.NotifyUser("Error retrieving PrinterExtensionContext from InterfaceId", NotifyType.ErrorMessage);
}
}
}
/// <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();
}
}