private async void BarcodeScannerProviderConnection_EnableScannerRequested(BarcodeScannerProviderConnection sender, BarcodeScannerEnableScannerRequestEventArgs args)
{
// For BarcodeScannerProviderConnection events,
// a deferral is not required if the only async operation
// is ReportCompletedAsync or ReportFailedAsync.
scannerEnabled = true;
await args.Request.ReportCompletedAsync();
}
public Provider(IBackgroundTaskInstance backgroundTask)
{
this.backgroundTask = backgroundTask;
var triggerDetails = (BarcodeScannerProviderTriggerDetails)backgroundTask.TriggerDetails;
connection = triggerDetails.Connection;
Initialize();
}
private async void BarcodeScannerProviderConnection_DisableScannerRequested(BarcodeScannerProviderConnection sender, BarcodeScannerDisableScannerRequestEventArgs args)
{
using (args.GetDeferral())
{
scannerEnabled = false;
// Stop frame reader when disabled
if (frameReader != null)
{
await frameReader.StopAsync();
}
await args.Request.ReportCompletedAsync();
}
}
protected virtual void Dispose(bool disposing)
{
if (disposed)
{
return;
}
if (disposing)
{
frameReader?.Dispose();
frameReader = null;
connection?.Dispose();
connection = null;
deferral?.Complete();
deferral = null;
disposed = true;
}
}
private async void BarcodeScannerProviderConnection_SetActiveSymbologiesRequested(BarcodeScannerProviderConnection sender, BarcodeScannerSetActiveSymbologiesRequestEventArgs args)
{
// Ensure all symbologies being set to active are supported.
foreach (var symbology in args.Request.Symbologies)
{
if (!decodeEngine.SupportedSymbologies.Contains(symbology))
{
// Found invalid symbology.
await args.Request.ReportFailedAsync();
return;
}
}
decodeEngine.ActiveSymbologies = new List <uint>(args.Request.Symbologies);
await args.Request.ReportCompletedAsync();
}
private async void BarcodeScannerProviderConnection_HideVideoPreviewRequested(BarcodeScannerProviderConnection sender, BarcodeScannerHideVideoPreviewRequestEventArgs args)
{
// There is no video preview running as background task. Simply report completed.
await args.Request.ReportCompletedAsync();
}
private async void BarcodeScannerProviderConnection_StopSoftwareTriggerRequested(BarcodeScannerProviderConnection sender, BarcodeScannerStopSoftwareTriggerRequestEventArgs args)
{
using (args.GetDeferral())
{
if (frameReader != null)
{
await frameReader.StopAsync();
}
await args.Request.ReportCompletedAsync();
}
}
private async void BarcodeScannerProviderConnection_StartSoftwareTriggerRequested(BarcodeScannerProviderConnection sender, BarcodeScannerStartSoftwareTriggerRequestEventArgs args)
{
using (args.GetDeferral())
{
bool readerStarted = false;
if (scannerEnabled)
{
if (frameReader == null)
{
// Create frame reader to read video frames
frameReader = await connection.CreateFrameReaderAsync(BitmapPixelFormat.Nv12, new BitmapSize()
{
Width = 1280, Height = 720
});
frameReader.FrameArrived += FrameReader_FrameArrived;
}
readerStarted = await frameReader.StartAsync();
}
if (readerStarted)
{
await args.Request.ReportCompletedAsync();
}
else
{
await args.Request.ReportFailedAsync();
}
}
}
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 async void BarcodeScannerProviderConnection_GetBarcodeSymbologyAttributesRequested(BarcodeScannerProviderConnection sender, BarcodeScannerGetSymbologyAttributesRequestEventArgs args)
{
BarcodeSymbologyAttributes attributes;
if (symbologyAttributes.TryGetValue(args.Request.Symbology, out attributes))
{
await args.Request.ReportCompletedAsync(attributes);
}
else
{
await args.Request.ReportFailedAsync(E_BOUNDS, "The requested symbology is not supported.");
}
}
