/// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached.
/// This parameter is typically used to configure the page.</param>
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
// Request the right to have background tasks run in the future. This need only be done once
// after the app is installed, but it is harmless to do it every time the app is launched.
if (await BackgroundExecutiondManager.RequestAccessAsync() == BackgroundAccessStatus.Denied)
{
// TODO: What?
}
// Acquire the set of background tasks that we already have registered. Store them into a dictionary, keyed
// by task name. (For each LE device, we will use a task name that is derived from its Bluetooth address).
Dictionary <string, BackgroundTaskRegistration> taskRegistrations = new Dictionary <string, BackgroundTaskRegistration>();
foreach (BackgroundTaskRegistration reg in BackgroundTaskRegistration.AllTasks.Values)
{
taskRegistrations[reg.Name] = reg;
}
// Get the list of paired Bluetooth LE devicdes, and add them to our 'devices' list. Associate each device with
// its pre-existing registration if any, and remove that registration from our dictionary.
Devices.Clear();
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector()))
{
BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromIdAsync(di.Id);
Racer device = new Racer(bleDevice);
if (taskRegistrations.ContainsKey(device.TaskName))
{
device.TaskRegistration = taskRegistrations[device.TaskName];
taskRegistrations.Remove(device.TaskName);
}
Devices.Add(device);
}
// Unregister any remaining background tasks that remain in our dictionary. These are tasks that we registered
// for Bluetooth LE devices that have since been unpaired.
foreach (BackgroundTaskRegistration reg in taskRegistrations.Values)
{
reg.Unregister(false);
}
}
/// <summary>
/// Get all available BT devices.
/// </summary>
/// <exception cref="UnauthorizedAccessException">You have not set correct capabilities for your platform.</exception>
/// <returns>Returns all available BT devices.</returns>
public async override Task <List <DeviceInformation> > GetAllDevicesAsync()
{
var selector = RfcommDeviceService.GetDeviceSelector(RfcommServiceId.SerialPort);
DeviceInformationCollection platformDevices;
try
{
platformDevices = await PlatformDeviceInformation.FindAllAsync(selector);
}
catch (UnauthorizedAccessException)
{
if (Debugger.IsAttached)
{
// This exception likely occured becaused you have not added this to Package.appxmanifest:
/*
* <m2:DeviceCapability Name="bluetooth.rfcomm">
* <m2:Device Id="any">
* <m2:Function Type="name:serialPort" />
* </m2:Device>
* </m2:DeviceCapability>
*/
Debugger.Break();
}
throw;
}
var devices = new List <DeviceInformation>();
foreach (var platformDevice in platformDevices)
{
var device = new DeviceInformation();
device.DisplayName = platformDevice.Name;
device.PlatformDeviceObject = platformDevice;
devices.Add(device);
}
return(devices);
}
private async void MainWindow_Loaded(object sender, RoutedEventArgs ea)
{
setLanguageList();
bool hasCamera = await setCameraListAsync();
if (hasCamera)
{
await InitializeMediaCaptureAsync();
setBrightnessControl();
initializeTimer();
}
return;
#region local functions in MainWindow_Loaded
void setLanguageList()
{
IReadOnlyList <UwpLanguage> langList = UwpOcrEngine.AvailableRecognizerLanguages;
this.LangComboBox.ItemsSource = langList;
this.LangComboBox.DisplayMemberPath = nameof(UwpLanguage.DisplayName);
this.LangComboBox.SelectedValuePath = nameof(UwpLanguage.LanguageTag);
var ocrEngine
= UwpOcrEngine.TryCreateFromUserProfileLanguages();
this.LangComboBox.SelectedValue = ocrEngine.RecognizerLanguage.LanguageTag;
}
async Task <bool> setCameraListAsync()
{
var devices = await UwpDeviceInformation.FindAllAsync(UwpDeviceClass.VideoCapture);
if (devices.Count == 0)
{
hideCameraUI();
return(false);
}
setupCameraComboBox(devices);
return(true);
void hideCameraUI()
{
this.CameraLabel.Visibility = Visibility.Collapsed;
this.CameraComboBox.Visibility = Visibility.Collapsed;
this.MonitorCameraButton.Visibility = Visibility.Collapsed;
this.CameraControlGrid.Visibility = Visibility.Collapsed;
this.OcrCameraButtan.Visibility = Visibility.Collapsed;
}
void setupCameraComboBox(IReadOnlyList <UwpDeviceInformation> deviceList)
{
this.CameraComboBox.ItemsSource = deviceList;
this.CameraComboBox.DisplayMemberPath = nameof(UwpDeviceInformation.Name);
this.CameraComboBox.SelectedValuePath = nameof(UwpDeviceInformation.Id);
this.CameraComboBox.SelectedIndex = 0;
}
}
void setBrightnessControl()
{
// [明るさ] スライダーを設定
var brightCtl = _mediaCapture.BrightnessControl;
this.BrightSlider.Minimum = brightCtl.Capabilities.Min;
this.BrightSlider.Maximum = brightCtl.Capabilities.Max;
if (brightCtl.TryGetValue(out double bright))
{
this.BrightSlider.Value = bright;
}
// [コントラスト] スライダーを設定
var contrastCtl = _mediaCapture.ContrastControl;
this.ContrastSlider.Minimum = contrastCtl.Capabilities.Min;
this.ContrastSlider.Maximum = contrastCtl.Capabilities.Max;
if (contrastCtl.TryGetValue(out double contrast))
{
this.ContrastSlider.Value = contrast;
}
}
void initializeTimer()
{
// CapturePhotoToStreamAsync() が、どうも毎秒1回程度しかキャプチャさせてくれないようだ。
// タイマー動作にする必要はなかったかもしれない。
_dispatcherTimer = new DispatcherTimer(DispatcherPriority.Normal)
{
Interval = TimeSpan.FromMilliseconds(333),
};
_dispatcherTimer.Tick += new EventHandler(OnTimerTickAsync);
_dispatcherTimer.Start();
}
#endregion
} // END MainWindow_Loaded
