/// <summary>
/// GetDeviceSelector method returns the string needed to identify a PosPrinter. This is passed to FindAllAsync method to get the list of devices currently available and we connect the first device.
/// </summary>
private async Task <bool> FindReceiptPrinter()
{
if (printer == null)
{
rootPage.NotifyUser("Finding printer", NotifyType.StatusMessage);
DeviceInformationCollection deviceCollection = await DeviceInformation.FindAllAsync(PosPrinter.GetDeviceSelector());
if (deviceCollection != null && deviceCollection.Count > 0)
{
DeviceInformation deviceInfo = deviceCollection[0];
printer = await PosPrinter.FromIdAsync(deviceInfo.Id);
if (printer != null)
{
if (printer.Capabilities.Receipt.IsPrinterPresent)
{
rootPage.NotifyUser("Got Printer with Device Id : " + printer.DeviceId, NotifyType.StatusMessage);
return(true);
}
}
else
{
rootPage.NotifyUser("No Printer found", NotifyType.ErrorMessage);
return(false);
}
}
else
{
rootPage.NotifyUser("No devices returned by FindAllAsync.", NotifyType.ErrorMessage);
return(false);
}
}
return(true);
}
async void ClaimSamePrinter_Click()
{
ClaimResultText.Text = "";
rootPage.NotifyUser("", NotifyType.StatusMessage);
if (rootPage.Printer == null)
{
rootPage.NotifyUser("Use scenario 1 to find a printer first.", NotifyType.ErrorMessage);
return;
}
using (var printer = await PosPrinter.FromIdAsync(rootPage.Printer.DeviceId))
{
if (printer == null)
{
rootPage.NotifyUser("Cannot create same printer as scenario 1.", NotifyType.ErrorMessage);
}
using (var claimedPrinter = await printer.ClaimPrinterAsync())
{
if (claimedPrinter != null)
{
ClaimResultText.Text = "Claimed the printer.";
// This scenario doesn't do anything with the printer aside from claim it.
// The "using" statement will dispose the claimed printer.
}
else
{
ClaimResultText.Text = "Did not claim the printer.";
}
}
// The "using" statement will dispose the duplicate printer.
}
}
// By default, use all connections types.
public static async Task <PosPrinter> GetFirstReceiptPrinterAsync(PosConnectionTypes connectionTypes = PosConnectionTypes.All)
{
return(await DeviceHelpers.GetFirstDeviceAsync(PosPrinter.GetDeviceSelector(connectionTypes),
async (id) =>
{
PosPrinter printer = await PosPrinter.FromIdAsync(id);
if (printer != null && printer.Capabilities.Receipt.IsPrinterPresent)
{
return printer;
}
// Dispose the unwanted printer.
printer?.Dispose();
return null;
}));
}
async void FindPrinter_Click()
{
isBusy = true;
UpdateButtons();
rootPage.NotifyUser("", NotifyType.StatusMessage);
rootPage.ReleaseAllPrinters();
// Select a PosPrinter device using the Device Picker.
DevicePicker devicePicker = new DevicePicker();
devicePicker.Filter.SupportedDeviceSelectors.Add(PosPrinter.GetDeviceSelector());
// Anchor the picker on the Find button.
GeneralTransform ge = FindButton.TransformToVisual(Window.Current.Content as UIElement);
Rect rect = ge.TransformBounds(new Rect(0, 0, FindButton.ActualWidth, FindButton.ActualHeight));
DeviceInformation deviceInfo = await devicePicker.PickSingleDeviceAsync(rect);
rootPage.deviceInfo = deviceInfo;
PosPrinter printer = null;
if (deviceInfo != null)
{
printer = await PosPrinter.FromIdAsync(deviceInfo.Id);
}
if (printer != null && printer.Capabilities.Receipt.IsPrinterPresent)
{
rootPage.Printer = printer;
rootPage.NotifyUser("Found receipt printer.", NotifyType.StatusMessage);
}
else
{
// Get rid of the printer we can't use.
printer?.Dispose();
rootPage.NotifyUser("Please select a device whose printer is present.", NotifyType.ErrorMessage);
}
isBusy = false;
UpdateButtons();
}
/// <summary>
/// Find the first receipt printer and create two instances of it.
/// </summary>
/// <returns></returns>
private async Task <bool> FindReceiptPrinterInstances()
{
if (printerInstance1 == null || printerInstance2 == null)
{
rootPage.NotifyUser("Finding printer", NotifyType.StatusMessage);
printerInstance1 = await DeviceHelpers.GetFirstReceiptPrinterAsync();
if (printerInstance1 != null)
{
rootPage.NotifyUser("Got Printer Instance 1 with Device Id : " + printerInstance1.DeviceId, NotifyType.StatusMessage);
// Create another instance of the same printer.
if (printerInstance2 != null)
{
printerInstance2.Dispose();
printerInstance2 = null;
}
printerInstance2 = await PosPrinter.FromIdAsync(printerInstance1.DeviceId);
if (printerInstance2 != null)
{
rootPage.NotifyUser("Got Printer Instance 2 with Device Id : " + printerInstance2.DeviceId, NotifyType.StatusMessage);
return(true);
}
else
{
rootPage.NotifyUser("Couldn't create second instance of printer.", NotifyType.StatusMessage);
}
return(false);
}
else
{
rootPage.NotifyUser("No Printer found", NotifyType.ErrorMessage);
return(false);
}
}
return(true);
}