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 void CreateFormatTableDialog()
{
SetButtonState(retrieveFormatsButton, false);
SetFormatListState(false);
string formatName = (string)storedFilesList.SelectedValue;
Connection printerConnection = null;
Task.Run(() => {
try {
printerConnection = connectionSelector.GetConnection();
printerConnection.Open();
ZebraPrinter printer = ZebraPrinterFactory.GetInstance(printerConnection);
byte[] formatData = printer.RetrieveFormatFromPrinter(formatName);
fieldDescDataVars = printer.GetVariableFields(Encoding.UTF8.GetString(formatData)).ToList();
fieldDescDataVars = FormatFieldDescriptionDataVars(fieldDescDataVars);
formatVariables = new ObservableCollection <FormatVariable>();
for (int i = 0; i < fieldDescDataVars.Count; ++i)
{
formatVariables.Add(new FormatVariable {
FieldName = fieldDescDataVars[i].FieldName, FieldValue = ""
});
}
try {
if (printerConnection != null)
{
printerConnection.Close();
}
} catch (ConnectionException) { }
ShowStoredFormatDialog(formatName);
} catch (Exception e) {
MessageBoxCreator.ShowError(e.Message, "Communication Error");
SetButtonState(retrieveFormatsButton, true);
SetFormatListState(true);
} finally {
try {
if (printerConnection != null && printerConnection.Connected)
{
printerConnection.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) { }
});
}
}
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;
});
}
}