I am trying to create a simple application which will have the functionality to switch on and off the flash light in a Windows Media Device.
I have initialized the camera as following:
var devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
var rearCamera = devices.FirstOrDefault(item => item.EnclosureLocation != null &&
item.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back);
if (rearCamera != null)
{
DeviceName.Content = rearCamera.Name;
FlashButton.Visibility = System.Windows.Visibility.Visible;
mediaCapture = new MediaCapture();
await mediaCapture.InitializeAsync(new MediaCaptureInitializationSettings
{
VideoDeviceId = rearCamera.Id
});
LowLagPhotoCapture lowLagCaptureMgr = null;
// Image properties
ImageEncodingProperties imgFormat = ImageEncodingProperties.CreateJpeg();
// Create LowLagPhotoCapture object
lowLagCaptureMgr = await mediaCapture.PrepareLowLagPhotoCaptureAsync(imgFormat);
}
And to switch on the flash I have written the following code:
var MyVideoDeviceController = mediaCapture.VideoDeviceController;
var MyTorch = MyVideoDeviceController.TorchControl;
var MyFlash = MyVideoDeviceController.FlashControl;
if (MyTorch.Supported)
{
MyTorch.PowerPercent = 100;
MyTorch.Enabled = true;
}
else
{
if (MyFlash.Supported)
{
MyFlash.PowerPercent = 100;
MyFlash.Enabled = true;
}
else
{
MessageBox.Show("No Flash and Torch Support", "Flash and Torch");
}
}
But seems both TorchControl and FlashControl are not supported in the code. I am not sure if am using the right APIs too. I am trying to run this on a Motion F5m - Tablet PC
Thanks in advance
The TorchControl is used for constant video light, so if you're taking a photograph, it's not the most appropriate control to use. One reason is that on many devices, video light will be dimmer than a photo flash, but especially because on some devices, the torch will only turn on while a video recording is in progress. Depending on the capabilities of the device, this may interfere with the ability to take photos.
You have the right idea setting MyFlash.Enabled = true, but just to be safe, I would also set MyFlash.Auto = false, so that the flash will fire each time, and not only when it's dark.
The CameraManualControls sample on the Microsoft GitHub repository shows you how to use the Flash and Torch controls, and many more. It targets Windows 10, though, so if you're on 8.1 you'll have to adapt the code or upgrade your tablet.
Now, all of the above is assuming that the device you're running your app on has flash support in the first place. When you say that the controls are not supported, that means that the camera driver on the device is not advertising the capability to Windows. I assume that the built-in Microsoft Camera app doesn't allow you to use the flash either?
I see the manufacturer of your tablet lists an "Illuminator Light" on their camera specs list, but there is a chance that the only way to control it is through their proprietary application. In that case you'd have to reach out to them for support.
Related
I'm trying to play the built-in webcam feed in a MediaElement within a UWP app. It works fine for a few users but there is no feed played for most and I'm lost on what could be the issue.
Some observations when the webcam feed doesn't play:
The code executes without any exceptions
The dialog that requests user permission to access the camera is shown
The LED indicating the webcam is in use turns on soon as it is executed, but there is no feed.
Skype and Camera apps work fine.
The app was working as expected until a week back. A few things that changed in the mean time that could have had an impact are
Installed Kaspersky
A bunch of windows updates
Uninstalled VS2017 professional edition & VS2019 Community edition and installed VS2019 Professional Edition
Some additional information that might be needed to narrow down the reason.
Webcam is enabled in the Package manifest of the app
App Target version: 18362
App Min version: 18362
Windows OS Version : 18362
Any help on this would be highly appreciated. Thanks much in advance!
Here is the piece of code used to play the webcam feed where VideoStreamer is a MediaElement.
private async Task PlayLiveVideo()
{
var allGroups = await MediaFrameSourceGroup.FindAllAsync();
var eligibleGroups = allGroups.Select(g => new
{
Group = g,
// For each source kind, find the source which offers that kind of media frame,
// or null if there is no such source.
SourceInfos = new MediaFrameSourceInfo[]
{
g.SourceInfos.FirstOrDefault(info => info.DeviceInformation?.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Front
&& info.SourceKind == MediaFrameSourceKind.Color),
g.SourceInfos.FirstOrDefault(info => info.DeviceInformation?.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back
&& info.SourceKind == MediaFrameSourceKind.Color)
}
}).Where(g => g.SourceInfos.Any(info => info != null)).ToList();
if (eligibleGroups.Count == 0)
{
System.Diagnostics.Debug.WriteLine("No source group with front and back-facing camera found.");
return;
}
var selectedGroupIndex = 0; // Select the first eligible group
MediaFrameSourceGroup selectedGroup = eligibleGroups[selectedGroupIndex].Group;
MediaFrameSourceInfo frontSourceInfo = selectedGroup.SourceInfos[0];
MediaCapture mediaCapture = new MediaCapture();
MediaCaptureInitializationSettings settings = new MediaCaptureInitializationSettings()
{
SourceGroup = selectedGroup,
SharingMode = MediaCaptureSharingMode.ExclusiveControl,
MemoryPreference = MediaCaptureMemoryPreference.Cpu,
StreamingCaptureMode = StreamingCaptureMode.Video,
};
try
{
await mediaCapture.InitializeAsync(settings);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("MediaCapture initialization failed: " + ex.Message);
return;
}
var frameMediaSource1 = MediaSource.CreateFromMediaFrameSource(mediaCapture.FrameSources[frontSourceInfo.Id]);
VideoStreamer.SetPlaybackSource(frameMediaSource1);
VideoStreamer.Play();
}
As mentioned by Faywang-MSFT here , it worked after marking the application as trusted in Kaspersky.
I just converted one of my apps to target Android API 9 (was targeting API 8); now when notifications are sent out, the volume of media is lowered and never comes back to full volume.
The app uses WebView to play media files. This was not happening prior to targeting API 9. I had to convert the app into level 9 so that I could upload to the Google Play Store. I am running a Samsung S7 which was originally designed for API level 6 (with the OS upgraded to 8.0), not sure if that has something to do with the issue. Another detail is that I use Xamarin.Android for development, not sure if that matters either.
Additionally, I forced the notifications to play a blank sound (a very short[couple ms] blank mp3) in the same build that I converted the app to target API 9:
var channelSilent = new Android.App.NotificationChannel(CHANNEL_ID, name + " Silent", Android.App.NotificationImportance.High)
{
Description = description
};
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build()
//blank is blank mp3 file with nothing in it, a few ms in duration
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3")
channelSilent.SetSound(uri, alarmAttributes);
...so it could also be the blank sound that is causing the ducking to malfunction, not the API change. Is there something to do with notification sound ducking that could be causing the issue? Is there any other way to mute a notification with Xamarin.Android other than playing a blank sound? That is one route I think would be worth trying to fix this issue.
Here is the code I am using to generate notifications:
private static List<CustomNotification> _sentNotificationList = new List<CustomNotification>();
private static NotificationManagerCompat _notificationManager;
public async void SendNotifications(List<CustomNotification> notificationList)
{
await Task.Run(() =>
{
try
{
var _ctx = Android.App.Application.Context;
if (_notificationManager == null)
{
_notificationManager = Android.Support.V4.App.NotificationManagerCompat.From(_ctx);
}
if (notificationList.Count == 0)
{
return;
}
int notePos = 0;
foreach (var note in notificationList)
{
var resultIntent = new Intent(_ctx, typeof(MainActivity));
var valuesForActivity = new Bundle();
valuesForActivity.PutInt(MainActivity.COUNT_KEY, _count);
valuesForActivity.PutString("URL", note._noteLink);
resultIntent.PutExtras(valuesForActivity);
var resultPendingIntent = PendingIntent.GetActivity(_ctx, MainActivity.NOTIFICATION_ID, resultIntent, PendingIntentFlags.UpdateCurrent);
resultIntent.AddFlags(ActivityFlags.SingleTop);
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build();
//I am playing this blank sound to prevent android from spamming sounds as the notifications get sent out
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3");
//if the notification is the first in our batch then use this
//code block to send the notifications with sound
if (!_sentNotificationList.Contains(note) && notePos == 0)
{
var builder = new Android.Support.V4.App.NotificationCompat.Builder(_ctx, MainActivity.CHANNEL_ID + 1)
.SetAutoCancel(true)
.SetContentIntent(resultPendingIntent) // Start up this activity when the user clicks the intent.
.SetContentTitle(note._noteText) // Set the title
.SetNumber(1) // Display the count in the Content Info
.SetSmallIcon(Resource.Drawable.bitchute_notification2)
.SetContentText(note._noteType)
.SetPriority(NotificationCompat.PriorityMin);
MainActivity.NOTIFICATION_ID++;
_notificationManager.Notify(MainActivity.NOTIFICATION_ID, builder.Build());
_sentNotificationList.Add(note);
notePos++;
}
//if the notification isn't the first in our batch, then use this
//code block to send the notifications without sound
else if (!_sentNotificationList.Contains(note))
{
var builder = new Android.Support.V4.App.NotificationCompat.Builder(_ctx, MainActivity.CHANNEL_ID)
.SetAutoCancel(true) // Dismiss the notification from the notification area when the user clicks on it
.SetContentIntent(resultPendingIntent) // Start up this activity when the user clicks the intent.
.SetContentTitle(note._noteText) // Set the title
.SetNumber(1) // Display the count in the Content Info
.SetSmallIcon(Resource.Drawable.bitchute_notification2)
.SetContentText(note._noteType)
.SetPriority(NotificationCompat.PriorityHigh);
MainActivity.NOTIFICATION_ID++;
_notificationManager.Notify(MainActivity.NOTIFICATION_ID, builder.Build());
_sentNotificationList.Add(note);
notePos++;
}
ExtStickyService._notificationsHaveBeenSent = true;
}
}
catch
{
}
});
}
In my MainActivity I've created two different notification channels: one is silent; the other uses default notification setting for the device:
void CreateNotificationChannel()
{
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build();
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3");
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
// Notification channels are new in API 26 (and not a part of the
// support library). There is no need to create a notification
// channel on older versions of Android.
return;
}
var name = "BitChute";
var description = "BitChute for Android";
var channelSilent = new Android.App.NotificationChannel(CHANNEL_ID, name + " Silent", Android.App.NotificationImportance.High)
{
Description = description
};
var channel = new Android.App.NotificationChannel(CHANNEL_ID + 1, name, Android.App.NotificationImportance.High)
{
Description = description
};
channel.LockscreenVisibility = NotificationVisibility.Private;
//here is where I set the sound for the silent channel... this could be the issue?
var notificationManager = (Android.App.NotificationManager)GetSystemService(NotificationService);
channelSilent.SetSound(uri, alarmAttributes);
notificationManager.CreateNotificationChannel(channel);
notificationManager.CreateNotificationChannel(channelSilent);
}
Full source: https://github.com/hexag0d/BitChute_Mobile_Android_BottomNav/tree/APILevel9
EDIT: something really interesting is that if I pulldown the system ui bar, the volume goes back to normal. Very strange workaround but it might help diagnose the cause.
DOUBLE EDIT: I used .SetSound(null, null) instead of using the blank .mp3 and the ducking works fine now. See comments
I'm developing an UWP app for Desktop and Mobile. I'd like using DeviceConnectionChangeTrigger to identify when my BT device is in range, but when i try using it, I cannot register background task cause it keeps return System.ArgumentException "Value does not fall within the expected range." when executing "Register" method of BackgroundTaskBuilder.
code is very simple
var current = BackgroundExecutionManager.GetAccessStatus();
if (current == BackgroundAccessStatus.Unspecified || current == BackgroundAccessStatus.Denied)
{
var result = await BackgroundExecutionManager.RequestAccessAsync();
if (result == BackgroundAccessStatus.Denied || result == BackgroundAccessStatus.Unspecified)
throw new Exception("You cannot register Access");
}
//I tested it with BT and BTLE device but no luck
//var devices = await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector());
var devices = await DeviceInformation.FindAllAsync(BluetoothDevice.GetDeviceSelector());
var device = devices.FirstOrDefault();
if (device == null) throw new Exception("Device not found");
var trigger = await DeviceConnectionChangeTrigger.FromIdAsync(device.Id);
//trigger.MaintainConnection = true;
var builder = new BackgroundTaskBuilder
{
Name = "BluetoothConnectionWatcher",
TaskEntryPoint = typeof(BluetoothConnectionWatcherTask).FullName
};
builder.SetTrigger(trigger);
//error on next line!
var r = builder.Register();
My project has Bluetooth capabilities and one background task registered with Bluetooth property flagged.
All Bluetooth functionalities work well and I can communicate with devices without problem.
I tried several BT and BTLE device and for all of them seems I have the same problem.
I tried on Desktop and Mobile version of Windows 10 (both last fast insider build). Same problem.
The device.Id returned by code is similar to "Bluetooth#Bluetooth00:1a:7d:da:71:0a-fc:58:fa:4c:17:0a" for every BT device i tried (of course 2nd MAC address change based on device...)
Any advice?
Thanks in advance
As far as I know, with BLE you should use the Triggers designed for it. Thus if it is characteristics change you would want to get knowledge about, then you should use GattCharacteristicNotificationTrigger, and example on using it can be found from my blog.
Then if it just BLE device availability, and you can detect yours via scanrecord data, then do use the BluetoothLEAdvertisementWatcherTrigger instead. My Friend Juhana has example fro this in his blog.
Can anyone say how to toggle flashlight in Windows Phone 8.1 using C#? It seems like there are lots of API changes in Windows Phone 8.1 and most of the API's in WP 8.0 are not supported. Answers are highly appreciated.
I'm able to use TorchControl on my Lumia 820 like this - first you have to specify which camera you will use - the default is front (I think that's why you may find some problems) and we want the back one - the one with flash light. Sample code:
// edit - I forgot to show GetCameraID:
private static async Task<DeviceInformation> GetCameraID(Windows.Devices.Enumeration.Panel desiredCamera)
{
DeviceInformation deviceID = (await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture))
.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == desiredCamera);
if (deviceID != null) return deviceID;
else throw new Exception(string.Format("Camera of type {0} doesn't exist.", desiredCamera));
}
// init camera
async private void InitCameraBtn_Click(object sender, RoutedEventArgs e)
{
var cameraID = await GetCameraID(Windows.Devices.Enumeration.Panel.Back);
captureManager = new MediaCapture();
await captureManager.InitializeAsync(new MediaCaptureInitializationSettings
{
StreamingCaptureMode = StreamingCaptureMode.Video,
PhotoCaptureSource = PhotoCaptureSource.VideoPreview,
AudioDeviceId = string.Empty,
VideoDeviceId = cameraID.Id
});
}
// then to turn on/off camera
var torch = captureManager.VideoDeviceController.TorchControl;
if (torch.Supported) torch.Enabled = true;
// turn off
if (torch.Supported) torch.Enabled = false;
Note that it's a good idea to call captureManager.Dispose() after you finish with it.
Note also that on some phones to turn on torch/flashlight you will need to start preview first.
Windows Phone 8.1 is the first version with a dedicated API for controlling the camera light. This API stems from Windows 8.1 but is usable in Windows Phone 8.1 projects and in Windows Phone Silverlight 8.1 projects.
var mediaDev = new MediaCapture();
await mediaDev.InitializeAsync();
var videoDev = mediaDev.VideoDeviceController;
var tc = videoDev.TorchControl;
if (tc.Supported)
{
if (tc.PowerSupported)
tc.PowerPercent = 100;
tc.Enabled = true;
}
Note:
Note: TorchControl.Supported returns false on most phones in WP8.1 developer preview. It is expected to be fixed by a firmware update by the time WP 8.1 is released. Tested Phones at the time of writing: Lumia 620, 822, 1020: not working, Lumia 1520: working.
In Nokia Lumia 1520, you use FlashControl to toggle the flash light instead of TorchControl.
//to switch OFF flash light
mediacapture.VideoDeviceController.FlashControl.Enabled = false;
//to switch ON flash light
mediacapture.VideoDeviceController.FlashControl.Enabled = true;
Doesn't work on my Lumia 1520. You need to start video recording to get flashlight working:
var videoEncodingProperties = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Vga);
var videoStorageFile = await KnownFolders.VideosLibrary.CreateFileAsync("tempVideo.mp4", CreationCollisionOption.GenerateUniqueName);
await captureManager.StartRecordToStorageFileAsync(videoEncodingProperties, videoStorageFile);
In my Lumia 1520. I need to start video recording and start preview to get flashlight working:
await captureManager.StartPreviewAsync();
I'm working on a mobile application (C#/WPF on a tablet PC) that prints to a bluetooth connected printer. Right now I just fire off a print job, and if the printer is not present the printer subsystem reports an error to the user. I'm not doing anything programatically with Bluetooth, just using PrintDialog().
I'd like to modify this process to detect the printer first - if it is not available, then I'll just store the document without printing. Is there a way in code for me to detect if the bluetooth device is connected/active/available?
If I look at the device in the Bluetooth panel under Control Panel, it doesn't seem to have any sort of status that reflects whether or not the device is available, so maybe this isn't possible.
I'm assuming the printer has already been setup and configured in Windows - all I need to do is detect if it is actually present at a given point in time.
Perhaps use the 32feet.NET library (of which I am the maintainer) and check if the printer is present before submitting the job. You'd need to know the Bluetooth address of the printer; can one get that from the system, or maybe you always know it.
Discovery on the MSFT Bluetooth stack always returns all known devices in amongst those in range :-( but we can use other means to detect the device's presence/absence. Perhaps using BluetoothDeviceInfo.GetServiceRecords in its BeginGetServiceRecords form. e.g. something like (not tested/compiled):
bool IsPresent(BluetoothAddress addr) // address from config somehow
{
BluetoothDeviceInfo bdi = new BluetoothDeviceInfo(addr);
if (bdi.Connected) {
return true;
}
Guid arbitraryClass = BluetoothService.Headset;
AsyncResult<bool> ourAr = new AsyncResult<bool>(); // Jeffrey Richter's impl
IAsyncResult ar = bdi.BeginGetService(arbitraryClass, IsPresent_GsrCallback, ourAr);
bool signalled = ourAr.AsyncWaitHandle.WaitOne(Timeout);
if (!signalled) {
return false; // Taken too long, so not in range
} else {
return ourAr.Result;
}
}
void IsPresent_GsrCallback(IAsyncResult ar)
{
AsyncResult<bool> ourAr = (AsyncResult<bool>)ar.AsyncState;
const bool IsInRange = true;
const bool completedSyncFalse = true;
try {
bdi.EndGetServiceResult(ar);
ourAr.SetAsCompleted(IsInRange, completedSyncFalse);
} catch {
// If this returns quickly, then it is in range and
// if slowly then out of range but caller will have
// moved on by then... So set true in both cases...
// TODO check what error codes we get here. SocketException(10108) iirc
ourAr.SetAsCompleted(IsInrange, completedSyncFalse);
}
}