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 Task AddStoredFormatsToFormatListAsync()
{
List <FormatViewModel> formats = new List <FormatViewModel>();
await Task.Factory.StartNew(async() => {
List <PrintStationDatabase.StoredFormat> storedFormats = await App.Database.GetStoredFormatsAsync();
foreach (PrintStationDatabase.StoredFormat storedFormat in storedFormats)
{
if (string.Equals(storedFormat.Extension, "zpl", StringComparison.OrdinalIgnoreCase))
{
formats.Add(new FormatViewModel {
DatabaseId = storedFormat.Id,
DriveLetter = storedFormat.DriveLetter,
Name = storedFormat.Name,
Extension = storedFormat.Extension,
Content = storedFormat.Content,
Source = FormatSource.LocalStorage,
OnDeleteButtonClicked = new Command(async(object parameter) => {
if (!ViewModel.IsPrinterFormatListRefreshing && !ViewModel.IsSavingFormat)
{
FormatViewModel format = parameter as FormatViewModel;
bool deleteFormat = await DisplayAlert("Delete Format", $"Are you sure you want to delete the stored format '{format.PrinterPath}'?", "Delete", "Cancel");
if (deleteFormat)
{
await Task.Factory.StartNew(() => {
ViewModel.IsDeletingFormat = true;
format.IsDeleting = true;
});
await App.Database.DeleteStoredFormatByIdAsync(format.DatabaseId);
await Task.Factory.StartNew(() => {
format.IsDeleting = false;
ViewModel.IsDeletingFormat = false;
});
await RefreshStoredFormatListAsync();
}
}
}),
OnPrintButtonClicked = new Command(async(object parameter) => {
if (!ViewModel.IsPrinterFormatListRefreshing && !ViewModel.IsSavingFormat)
{
FormatViewModel format = parameter as FormatViewModel;
await PushPageAsync(new PrintFormatPage(ViewModel.SelectedPrinter, format));
}
})
});
}
}
formats.ForEach(ViewModel.StoredFormatList.Add);
});
}
public PrintFormatPage(DiscoveredPrinter selectedPrinter, FormatViewModel format)
{
InitializeComponent();
this.selectedPrinter = selectedPrinter;
this.format = format;
BindingContext = viewModel;
Device.BeginInvokeOnMainThread(async() => {
await PopulateVariableFieldListAsync();
});
}
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) { }
});
}
}
