private async Task <string> RetrieveFormatContentAsync(FormatViewModel format)
{
string formatContent = null;
Connection connection = null;
try {
await Task.Factory.StartNew(() => {
connection = ConnectionCreator.Create(ViewModel.SelectedPrinter);
connection.Open();
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(connection);
ZebraPrinterLinkOs linkOsPrinter = ZebraPrinterFactory.CreateLinkOsPrinter(printer);
formatContent = Encoding.UTF8.GetString(printer.RetrieveFormatFromPrinter(format.PrinterPath));
});
} catch (Exception e) {
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
});
}
return(formatContent);
}
private async void SelectButton_Clicked(object sender, EventArgs eventArgs)
{
if (!viewModel.IsSelectingPrinter && Navigation.NavigationStack.Count > 0 && Navigation.NavigationStack.Last().GetType() == typeof(SelectPrinterPage))
{
await Task.Factory.StartNew(() => {
viewModel.IsSelectingPrinter = true;
});
try {
DiscoveredPrinter selectedPrinter = (DiscoveredPrinter)PrinterList.SelectedItem;
Connection connection = null;
try {
await Task.Factory.StartNew(() => {
connection = ConnectionCreator.Create(selectedPrinter);
connection.Open();
});
} catch (Exception e) {
await AlertCreator.ShowErrorAsync(this, e.Message);
return;
} finally {
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
});
}
await Task.Factory.StartNew(() => {
mainPage.ViewModel.SelectedPrinter = selectedPrinter;
});
mainPage.RefreshFormatLists();
await Navigation.PopAsync();
} finally {
await Task.Factory.StartNew(() => {
viewModel.IsSelectingPrinter = false;
});
}
}
}
private async Task AddPrinterFormatsToFormatListAsync()
{
Connection connection = null;
try {
List <FormatViewModel> formats = new List <FormatViewModel>();
await Task.Factory.StartNew(() => {
connection = ConnectionCreator.Create(ViewModel.SelectedPrinter);
connection.Open();
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(connection);
ZebraPrinterLinkOs linkOsPrinter = ZebraPrinterFactory.CreateLinkOsPrinter(printer);
string[] formatPrinterPaths = printer.RetrieveFileNames(new string[] { "ZPL" });
foreach (string formatPrinterPath in formatPrinterPaths)
{
int colonIndex = formatPrinterPath.IndexOf(":");
string driveLetter = formatPrinterPath.Substring(0, colonIndex);
string name = formatPrinterPath.Substring(colonIndex + 1, formatPrinterPath.LastIndexOf(".") - colonIndex - 1);
string extension = formatPrinterPath.Substring(formatPrinterPath.LastIndexOf(".") + 1);
if (!string.Equals(driveLetter, "Z", StringComparison.OrdinalIgnoreCase)) // Ignore all formats stored on printer's Z drive
{
formats.Add(new FormatViewModel {
DriveLetter = driveLetter,
Name = name,
Extension = extension,
Content = null, // Populate this later, upon navigating to print format page
Source = FormatSource.Printer,
OnSaveButtonClicked = new Command(async(object parameter) => {
if (!ViewModel.IsSavingFormat && !ViewModel.IsDeletingFormat && !ViewModel.IsStoredFormatListRefreshing)
{
FormatViewModel format = parameter as FormatViewModel;
await Task.Factory.StartNew(() => {
ViewModel.IsSavingFormat = true;
format.IsSaving = true;
});
await SavePrinterFormatAsync(format);
await Task.Factory.StartNew(() => {
format.IsSaving = false;
ViewModel.IsSavingFormat = false;
});
await RefreshStoredFormatListAsync();
}
}),
OnPrintButtonClicked = new Command(async(object parameter) => {
if (!ViewModel.IsSavingFormat)
{
FormatViewModel format = parameter as FormatViewModel;
await PushPageAsync(new PrintFormatPage(ViewModel.SelectedPrinter, format));
}
})
});
}
}
formats.ForEach(ViewModel.PrinterFormatList.Add);
});
} catch (Exception e) {
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
});
}
}
private async Task SavePrinterFormatAsync(FormatViewModel format)
{
PrintStationDatabase.StoredFormat storedFormat = null;
Connection connection = null;
bool fileWriteAttempted = false;
bool linePrintEnabled = false;
try {
await Task.Factory.StartNew(async() => {
connection = ConnectionCreator.Create(ViewModel.SelectedPrinter);
connection.Open();
string originalPrinterLanguage = SGD.GET(PrintFormatPage.DeviceLanguagesSgd, connection);
linePrintEnabled = "line_print".Equals(originalPrinterLanguage, StringComparison.OrdinalIgnoreCase);
if (linePrintEnabled)
{
SGD.SET(PrintFormatPage.DeviceLanguagesSgd, "zpl", connection);
}
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(connection);
ZebraPrinterLinkOs linkOsPrinter = ZebraPrinterFactory.CreateLinkOsPrinter(printer);
string formatContent = Encoding.UTF8.GetString(printer.RetrieveFormatFromPrinter(format.PrinterPath));
fileWriteAttempted = true;
storedFormat = new PrintStationDatabase.StoredFormat {
DriveLetter = format.DriveLetter,
Name = format.Name,
Extension = format.Extension,
Content = formatContent
};
await App.Database.SaveStoredFormatAsync(storedFormat);
});
} catch (Exception e) {
await Task.Factory.StartNew(async() => {
if (fileWriteAttempted && storedFormat != null)
{
await App.Database.DeleteStoredFormatByIdAsync(storedFormat.Id);
}
});
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
if (linePrintEnabled)
{
await Task.Factory.StartNew(() => {
try {
connection?.Open();
SGD.SET(PrintFormatPage.DeviceLanguagesSgd, "line_print", connection);
} catch (ConnectionException) { }
});
}
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
});
}
}
public MainPage()
{
InitializeComponent();
BindingContext = ViewModel;
if (Device.RuntimePlatform != Device.WPF || !DependencyService.Get <IPlatformHelper>().IsWindows10())
{
ToolbarItems.Remove(BluetoothHelpButton); // Bluetooth help dialog is specific to Windows 10
}
try {
if (DependencyService.Get <INfcManager>().IsNfcAvailable())
{
DependencyService.Get <INfcManager>().TagScanned += async(object sender, string nfcData) => {
Device.BeginInvokeOnMainThread(async() => {
await Navigation.PopToRootAsync(); // Must call Navigation.PopToRootAsync() on UI thread on Windows tablets
});
await Task.Factory.StartNew(() => {
ViewModel.IsSelectingNfcPrinter = true;
ViewModel.SelectedPrinter = null;
try {
ViewModel.StoredFormatList.Clear();
} catch (NotImplementedException) {
ViewModel.StoredFormatList.Clear(); // Workaround for Xamarin.Forms.Platform.WPF issue: https://github.com/xamarin/Xamarin.Forms/issues/3648
}
try {
ViewModel.PrinterFormatList.Clear();
} catch (NotImplementedException) {
ViewModel.PrinterFormatList.Clear(); // Workaround for Xamarin.Forms.Platform.WPF issue: https://github.com/xamarin/Xamarin.Forms/issues/3648
}
});
Connection connection = null;
DiscoveredPrinter printer = null;
bool success = false;
try {
await Task.Factory.StartNew(() => {
printer = NfcDiscoverer.DiscoverPrinter(nfcData);
connection = printer.GetConnection();
try {
connection.Open(); // Test connection
} catch (Exception e) {
throw new ConnectionException("Could not open connection. Please check your printer and device settings and try again.", e);
}
success = true;
});
} catch (Exception e) {
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (Exception) { }
if (success)
{
ViewModel.SelectedPrinter = printer;
ViewModel.IsSelectingNfcPrinter = false;
RefreshFormatLists();
}
else
{
ViewModel.IsSelectingNfcPrinter = false;
}
});
}
};
}
} catch (TypeLoadException) { } // NFC is not supported on Windows 7
InitializeStoredFormats();
}
private async Task PopulateVariableFieldListAsync()
{
await Task.Factory.StartNew(() => {
viewModel.IsVariableFieldListRefreshing = true;
try {
viewModel.FormatVariableList.Clear();
} catch (NotImplementedException) {
viewModel.FormatVariableList.Clear(); // Workaround for Xamarin.Forms.Platform.WPF issue: https://github.com/xamarin/Xamarin.Forms/issues/3648
}
});
Connection connection = null;
bool linePrintEnabled = false;
try {
await Task.Factory.StartNew(() => {
connection = ConnectionCreator.Create(selectedPrinter);
connection.Open();
string originalPrinterLanguage = SGD.GET(DeviceLanguagesSgd, connection);
linePrintEnabled = "line_print".Equals(originalPrinterLanguage, StringComparison.OrdinalIgnoreCase);
if (linePrintEnabled)
{
SGD.SET(DeviceLanguagesSgd, "zpl", connection);
}
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(connection);
ZebraPrinterLinkOs linkOsPrinter = ZebraPrinterFactory.CreateLinkOsPrinter(printer);
if (format.Source == FormatSource.Printer)
{
format.Content = Encoding.UTF8.GetString(printer.RetrieveFormatFromPrinter(format.PrinterPath));
}
FieldDescriptionData[] variableFields = printer.GetVariableFields(format.Content);
foreach (FieldDescriptionData variableField in variableFields)
{
viewModel.FormatVariableList.Add(new FormatVariable {
Name = variableField.FieldName ?? $"Field {variableField.FieldNumber}",
Index = variableField.FieldNumber,
});
}
});
} catch (Exception e) {
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
if (linePrintEnabled)
{
await ResetPrinterLanguageToLinePrintAsync(connection);
}
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
viewModel.IsVariableFieldListRefreshing = false;
});
}
}
private async void PrintButton_Clicked(object sender, EventArgs eventArgs)
{
await Task.Factory.StartNew(() => {
viewModel.IsSendingPrintJob = true;
});
Connection connection = null;
bool linePrintEnabled = false;
try {
await Task.Factory.StartNew(() => {
connection = ConnectionCreator.Create(selectedPrinter);
connection.Open();
string originalPrinterLanguage = SGD.GET(DeviceLanguagesSgd, connection);
linePrintEnabled = "line_print".Equals(originalPrinterLanguage, StringComparison.OrdinalIgnoreCase);
if (linePrintEnabled)
{
SGD.SET(DeviceLanguagesSgd, "zpl", connection);
}
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(connection);
ZebraPrinterLinkOs linkOsPrinter = ZebraPrinterFactory.CreateLinkOsPrinter(printer);
string errorMessage = GetPrinterStatusErrorMessage(printer.GetCurrentStatus());
if (errorMessage != null)
{
throw new PrinterNotReadyException($"{errorMessage}. Please check your printer and try again.");
}
else
{
if (format.Source != FormatSource.Printer)
{
connection.Write(Encoding.UTF8.GetBytes(format.Content));
}
linkOsPrinter.PrintStoredFormatWithVarGraphics(format.PrinterPath, BuildFormatVariableDictionary(), "UTF-8");
}
});
if (linePrintEnabled)
{
await ResetPrinterLanguageToLinePrintAsync(connection);
}
await Task.Factory.StartNew(() => {
viewModel.IsSendingPrintJob = false;
});
} catch (PrinterNotReadyException e) {
if (linePrintEnabled)
{
await ResetPrinterLanguageToLinePrintAsync(connection);
}
await Task.Factory.StartNew(() => {
viewModel.IsSendingPrintJob = false;
});
await AlertCreator.ShowAsync(this, "Printer Error", e.Message);
} catch (Exception e) {
if (linePrintEnabled)
{
await ResetPrinterLanguageToLinePrintAsync(connection);
}
await Task.Factory.StartNew(() => {
viewModel.IsSendingPrintJob = false;
});
await AlertCreator.ShowErrorAsync(this, e.Message);
} finally {
await Task.Factory.StartNew(() => {
try {
connection?.Close();
} catch (ConnectionException) { }
});
}
}