/// <summary>
/// This method is invoked when a printer is selected on the UI.
/// Displays the print jobs in the selected printer's queue.
/// </summary>
private void Printer_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
try
{
// Remove the current printer queue view (if any) before displaying the new view.
if (currentPrinterQueueView != null)
{
currentPrinterQueueView.OnChanged -= OnPrinterQueueViewChanged;
currentPrinterQueueView = null;
}
// Retrieve a COM IPrinterExtensionContext object, using the static WinRT factory.
// Then instantiate one "PrinterExtensionContext" object that allows operations on the COM object.
PrinterInfo queue = (PrinterInfo)PrinterComboBox.SelectedItem;
Object comComtext = Windows.Devices.Printers.Extensions.PrintExtensionContext.FromDeviceId(queue.DeviceId);
PrinterExtensionContext context = new PrinterExtensionContext(comComtext);
// Display the printer queue view.
const int FirstPrintJobEnumerated = 0;
const int LastPrintJobEnumerated = 10;
currentPrinterQueueView = context.Queue.GetPrinterQueueView(FirstPrintJobEnumerated, LastPrintJobEnumerated);
currentPrinterQueueView.OnChanged += OnPrinterQueueViewChanged;
}
catch (Exception exception)
{
rootPage.NotifyUser("Caught an exception: " + exception.Message, NotifyType.ErrorMessage);
}
}
/// <summary>
/// Event handler for clicks on the "Send bidi request" button.
/// </summary>
private void SendBidiRequest_Click(object sender, RoutedEventArgs e)
{
try
{
PrinterInfo queue = (PrinterInfo)PrinterComboBox.SelectedItem;
// Retrieve a COM IPrinterExtensionContext object, using the static WinRT factory.
// Then instantiate one "PrinterExtensionContext" object that allows operations on the COM object.
Object comComtext = Windows.Devices.Printers.Extensions.PrintExtensionContext.FromDeviceId(queue.DeviceId);
PrinterExtensionContext context = new PrinterExtensionContext(comComtext);
// Create an instance of the callback object, and perform an asynchronous 'bidi set' operation.
PrinterBidiSetRequestCallback callback = new PrinterBidiSetRequestCallback();
// Add an event handler to the callback object's OnBidiResponseReceived event.
// The event handler will be invoked once the Bidi response is received.
callback.OnBidiResponseReceived += OnBidiResponseReceived;
// Send the Bidi "Set" query asynchronously.
IPrinterExtensionAsyncOperation operationContext
= context.Queue.SendBidiSetRequestAsync(BidiQueryInput.Text, callback);
// Note: The 'operationContext' object can be used to cancel the operation if required.
}
catch (Exception exception)
{
rootPage.NotifyUser("Caught an exception: " + exception.Message, NotifyType.ErrorMessage);
}
}