ClaimedBarcodeScanner.ReleaseDeviceRequested Kejadian
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Terjadi ketika perangkat mendapatkan permintaan untuk merilis klaim eksklusifnya.
// Register
event_token ReleaseDeviceRequested(EventHandler<ClaimedBarcodeScanner> const& handler) const;
// Revoke with event_token
void ReleaseDeviceRequested(event_token const* cookie) const;
// Revoke with event_revoker
ClaimedBarcodeScanner::ReleaseDeviceRequested_revoker ReleaseDeviceRequested(auto_revoke_t, EventHandler<ClaimedBarcodeScanner> const& handler) const;
public event System.EventHandler<ClaimedBarcodeScanner> ReleaseDeviceRequested;
function onReleaseDeviceRequested(eventArgs) { /* Your code */ }
claimedBarcodeScanner.addEventListener("releasedevicerequested", onReleaseDeviceRequested);
claimedBarcodeScanner.removeEventListener("releasedevicerequested", onReleaseDeviceRequested);
- or -
claimedBarcodeScanner.onreleasedevicerequested = onReleaseDeviceRequested;
Public Custom Event ReleaseDeviceRequested As EventHandler(Of ClaimedBarcodeScanner)
Jenis Acara
Contoh
Contoh berikut menunjukkan cara menyiapkan penanganan aktivitas.
void Scenario1::ScenarioStartScanButton_Click(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
// Create the barcode scanner.
create_task(CreateDefaultScannerObject()).then([this](void)
{
if (scanner != nullptr)
{
// Claim the scanner for exclusive use by your application.
create_task(ClaimScanner()).then([this](void)
{
if (claimedScanner)
{
// Add a release device requested event handler. If this event is not handled,
// another app can claim the barcode scanner.
releaseDeviceRequestedToken = claimedScanner->ReleaseDeviceRequested::add(ref new EventHandler<ClaimedBarcodeScanner^>(this, &Scenario1::OnReleaseDeviceRequested));
/// Add a data receive event handler.
dataReceivedToken = claimedScanner->DataReceived::add(ref new TypedEventHandler<ClaimedBarcodeScanner^, BarcodeScannerDataReceivedEventArgs^>(this, &Scenario1::OnDataReceived));
UpdateOutput("Attached the DataReceived Event handler.");
// Set the app to decode the raw data from the barcode scanner
claimedScanner->IsDecodeDataEnabled = true;
// Enable the scanner.
create_task(EnableScanner()).then([this](void)
{
UpdateOutput("Ready to Scan.");
// Reset the button state
ScenarioEndScanButton->IsEnabled = true;
ScenarioStartScanButton->IsEnabled = false;
});
}
});
}
});
}
private async void ScenarioStartScanButton_Click(object sender, RoutedEventArgs e)
{
// Create the barcode scanner.
if (await CreateDefaultScannerObject())
{
// Claim the scanner for exclusive use by your application.
if (await ClaimScanner())
{
// Add a release device requested event handler. If this event is not handled,
// another app can claim the barcode scanner.
claimedScanner.ReleaseDeviceRequested += claimedScanner_ReleaseDeviceRequested;
// Add a data receive event handler.
claimedScanner.DataReceived += claimedScanner_DataReceived;
UpdateOutput("Attached the DataReceived Event handler.");
// Set the app to decode the raw data from the barcode scanner
claimedScanner.IsDecodeDataEnabled = true;
// Enable the scanner.
if (await EnableScanner())
{
// Reset the button state
ScenarioEndScanButton.IsEnabled = true;
ScenarioStartScanButton.IsEnabled = false;
UpdateOutput("Ready to Scan.");
}
}
}
else
{
UpdateOutput("No Barcode Scanner found");
}
}
void Scenario1::OnReleaseDeviceRequested(Platform::Object ^sender, Windows::Devices::PointOfService::ClaimedBarcodeScanner ^args)
{
Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
[this,args]()
{
args->RetainDevice();
UpdateOutput("Received event ReleaseDeviceRequested. Retaining the barcode scanner.");
}));
}
async void claimedScanner_ReleaseDeviceRequested(object sender, ClaimedBarcodeScanner e)
{
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
e.RetainDevice();
});
}
Keterangan
Jika aplikasi Anda menerima peristiwa ReleaseDeviceRequested dari aplikasi lain, aplikasi tersebut mungkin kehilangan klaim eksklusifnya kecuali aplikasi Anda mempertahankan perangkat.
Berlaku untuk
Lihat juga
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