private async void BarcodeScannerProviderConnection_SetBarcodeSymbologyAttributesRequested(BarcodeScannerProviderConnection sender, BarcodeScannerSetSymbologyAttributesRequestEventArgs args)
{
// Update the symbology attributes for the specified symbology.
BarcodeSymbologyAttributes newAttributes = args.Request.Attributes;
BarcodeSymbologyAttributes existingAttributes;
if (symbologyAttributes.TryGetValue(args.Request.Symbology, out existingAttributes))
{
// Our sample does not support these properties, but we update them for illustration purposes.
if (existingAttributes.IsDecodeLengthSupported)
{
existingAttributes.DecodeLength1 = newAttributes.DecodeLength1;
existingAttributes.DecodeLength2 = newAttributes.DecodeLength2;
existingAttributes.DecodeLengthKind = newAttributes.DecodeLengthKind;
}
if (existingAttributes.IsCheckDigitTransmissionSupported)
{
existingAttributes.IsCheckDigitTransmissionEnabled = newAttributes.IsCheckDigitTransmissionEnabled;
}
if (existingAttributes.IsCheckDigitValidationSupported)
{
existingAttributes.IsCheckDigitValidationEnabled = newAttributes.IsCheckDigitValidationEnabled;
}
// If we supported these properties, we would also have to update the parameters of the decoder
// at this point.
await args.Request.ReportCompletedAsync();
}
else
{
await args.Request.ReportFailedAsync(E_BOUNDS, "The requested symbology is not supported.");
}
}
private void Initialize()
{
deferral = backgroundTask.GetDeferral();
RegisterEventHandlers();
// Set provider information. This information is localized, so read it from our resources.
ResourceLoader resourceLoader = ResourceLoader.GetForViewIndependentUse();
connection.CompanyName = resourceLoader.GetString("Company");
connection.Name = resourceLoader.GetString("Product");
connection.Version = resourceLoader.GetString("Version");
decodeEngine = new DecodeEngine();
// Our decode engine does not support any of these features.
var attributesBuilder = new BarcodeSymbologyAttributesBuilder
{
IsCheckDigitTransmissionSupported = false,
IsCheckDigitValidationSupported = false,
IsDecodeLengthSupported = false,
};
// Tell the system which symbologies we support.
foreach (uint symbology in decodeEngine.SupportedSymbologies)
{
connection.SupportedSymbologies.Add(symbology);
// Populate a dictionary for tracking symbology attributes for each supported symbology.
// (This step is unnecessary in the case of this sample because none of these properties
// is marked as supported in our BarcodeSymbologyAttributesBuilder, but we track them
// in this sample in order to show how it could be done.)
BarcodeSymbologyAttributes defaultAttributes = attributesBuilder.CreateAttributes();
if (attributesBuilder.IsDecodeLengthSupported)
{
// These are the default values, but we set them explicitly for demonstration purposes.
defaultAttributes.DecodeLength1 = 0;
defaultAttributes.DecodeLength2 = 0;
defaultAttributes.DecodeLengthKind = BarcodeSymbologyDecodeLengthKind.AnyLength;
}
if (attributesBuilder.IsCheckDigitTransmissionSupported)
{
// This is the default value, but we set it explicitly for demonstration purposes.
defaultAttributes.IsCheckDigitTransmissionEnabled = false;
}
if (attributesBuilder.IsCheckDigitValidationSupported)
{
// This is the default value, but we set it explicitly for demonstration purposes.
defaultAttributes.IsCheckDigitValidationEnabled = false;
}
symbologyAttributes.Add(symbology, defaultAttributes);
}
// Start the connection after
// 1. Provider information is set
// 2. Supported symbologies are added
// 3. All event handlers are registered
connection.Start();
}
/// <summary>
/// Adds the barcode symbologies, which have specified attribute.
/// </summary>
/// <param name="result">The list to add.</param>
/// <param name="symbologyAttribute">The barcode symbology attribute.</param>
private void AddBarcodeSymbologyByAttributes(List <BarcodeSymbology> result, BarcodeSymbologyAttributes symbologyAttribute)
{
foreach (BarcodeSymbology barcodeSymbology in _barcodeSymbologies)
{
if ((barcodeSymbology.Attributes & symbologyAttribute) != 0)
{
result.Add(barcodeSymbology);
}
}
}
/// <summary>
/// Event handler for Symbology listbox selection changed.
/// Get symbology attributes and populate attribute UI components
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private async void SymbologySelection_Changed(object sender, SelectionChangedEventArgs args)
{
if (claimedScanner != null)
{
SymbologyListEntry symbologyListEntry = (SymbologyListEntry)SymbologyListBox.SelectedItem;
if (symbologyListEntry != null)
{
SetSymbologyAttributesButton.IsEnabled = false;
try
{
symbologyAttributes = await claimedScanner.GetSymbologyAttributesAsync(symbologyListEntry.Id);
}
catch (Exception)
{
symbologyAttributes = null;
}
if (symbologyAttributes != null)
{
SetSymbologyAttributesButton.IsEnabled = true;
// initialize attributes UIs
EnableCheckDigit.IsEnabled = symbologyAttributes.IsCheckDigitValidationSupported;
EnableCheckDigit.IsChecked = symbologyAttributes.IsCheckDigitValidationEnabled;
TransmitCheckDigit.IsEnabled = symbologyAttributes.IsCheckDigitTransmissionSupported;
TransmitCheckDigit.IsChecked = symbologyAttributes.IsCheckDigitTransmissionEnabled;
SetDecodeRangeLimits.IsEnabled = symbologyAttributes.IsDecodeLengthSupported;
bool decodeLengthEnabled = (symbologyAttributes.DecodeLengthKind == BarcodeSymbologyDecodeLengthKind.Range);
SetDecodeRangeLimits.IsChecked = decodeLengthEnabled;
if (decodeLengthEnabled)
{
MinimumDecodeLength.Value = Math.Min(symbologyAttributes.DecodeLength1, symbologyAttributes.DecodeLength2);
MaximumDecodeLength.Value = Math.Max(symbologyAttributes.DecodeLength1, symbologyAttributes.DecodeLength2);
}
}
else
{
rootPage.NotifyUser("Symbology attributes are not available.", NotifyType.ErrorMessage);
EnableCheckDigit.IsEnabled = false;
TransmitCheckDigit.IsEnabled = false;
SetDecodeRangeLimits.IsEnabled = false;
}
}
}
}
/// <summary>
/// Reset the Scenario state
/// </summary>
private void ResetTheScenarioState()
{
if (claimedScanner != null)
{
// Detach the event handlers
claimedScanner.DataReceived -= claimedScanner_DataReceived;
claimedScanner.ReleaseDeviceRequested -= claimedScanner_ReleaseDeviceRequested;
// Release the Barcode Scanner and set to null
claimedScanner.Dispose();
claimedScanner = null;
}
if (scanner != null)
{
scanner.Dispose();
scanner = null;
}
symbologyAttributes = null;
// Reset the UI if we are still the current page.
if (Frame.Content == this)
{
rootPage.NotifyUser("Click the start scanning button to begin.", NotifyType.StatusMessage);
this.ScenarioOutputScanData.Text = "No data";
this.ScenarioOutputScanDataLabel.Text = "No data";
this.ScenarioOutputScanDataType.Text = "No data";
// reset the button state
ScenarioEndScanButton.IsEnabled = false;
ScenarioStartScanButton.IsEnabled = true;
SetSymbologyAttributesButton.IsEnabled = false;
EnableCheckDigit.IsEnabled = false;
TransmitCheckDigit.IsEnabled = false;
SetDecodeRangeLimits.IsEnabled = false;
// reset symbology list
listOfSymbologies.Clear();
}
}
