Develop Reference

HidSharp Never Receives Input Report

I'm attempting to use HidSharp to read reports from a Vendor USB HID device using the below code, but I never manage to poll any input.
var device = DeviceList.Local.GetHidDevices().Where(d => /* My Vendor stuff */).First();
var deviceDescriptor = device.GetReportDescriptor();
if (device.TryOpen(out var inputStream))
{
var inputReport = deviceDescriptor.InputReports.First();
var inputReportParser = inputReport.DeviceItem.CreateDeviceItemInputParser();
var inputReportReciever = deviceDescriptor.CreateHidDeviceInputReceiver();
var inputReportBuffer = new byte[inputReport.Length];
while (inputReportReciever.IsRunning)
{
if (inputReportReciever.WaitHandle.WaitOne(10000))
{
while (inputReportReciever.TryRead(inputReportBuffer, 0, out var report))
{
if (inputReportParser.TryParseReport(inputReportBuffer, 0, report))
{
if (inputReportParser.HasChanged)
{
var data = inputReportParser.GetValue(inputReportParser.GetNextChangedIndex());
Console.WriteLine("Data: " + data.ToString());
}
}
}
}
}
}
I can see in the device manager that the device is recognized as an HID USB device, and Wireshark shows that I am sending periodic reports like so:
(I'm a java developer so I'm really struggling with Visual Studio) I can't step in to the library to see what's happening, but there are no errors being thrown and the 'test' included with the project parses reports from at least one other USB device (a headset) so the library seems ok. I'm not at all sure how to proceed with debugging further. Any direction on this library or USB is appreciated.

How to fix exception Device xxx disconnected while writing characteristic with yyy in xamarin forms?

I am creating a BLE app where I am successfully connecting to a BLE device. I am able to read the GATT characteristics as well. But when I try to do write operation I get exception
Device xxx disconnected while writing characteristic with yyy
This is my code
private async Task<string> ProcessDeviceInformationService(IService deviceInfoService)
{
try
{
await adapter.ConnectToDeviceAsync(device);
var sb = new StringBuilder("Getting information from Device Information service: \n");
var characteristics = await deviceInfoService.GetCharacteristicsAsync();
var characteristic = await deviceInfoService.GetCharacteristicAsync(Guid.Parse("00002b0f-0000-1000-8000-00805f9b34fb"));
//{
try
{
deviceInfoService.GetCharacteristicAsync(GattCharacteristicIdentifiers.DataExchange);
if (characteristic != null)
{
var sbnew = new StringBuilder("BLE Characteristics\n");
byte[] senddata = Encoding.UTF8.GetBytes(string.IsNullOrEmpty(SendMessageLabel.Text) ? "0x21" : SendMessageLabel.Text);
await Task.Delay(300);
var newbytes = await characteristic.WriteAsync(senddata);
byte[] characteristicsvalue = characteristic.Value;
var str = Encoding.UTF8.GetString(characteristicsvalue);
sbnew.AppendLine($"Characteristics found on this device: {string.Join(", ", str.ToString())}");
CharactericsLabel.Text = sbnew.ToString();
}
}
catch (Exception ex)
{
return ex.Message;
}
return CharactericsLabel.Text;
}
catch (Exception ex)
{
return ex.ToString();
}
}
After some search I found that I need to pass hexadecimal value.Even I tried sending hexadecimal value as you can see in code but it's not working. For android its working fine but for iOS it is still showing this exception.I'm using device Iphone 8 plus and OS version of Iphone is 13.5.1.The write operation works in Light Blue app which I downloaded from App store for iOS. My write type is set to default which is write with response. But it is giving exception in my xamarin app only for the iOS part. I'm using latest stable version 2.1.1 of Plugin.BLE. I have no clue how to fix this any suggestions?

I fixed this exception by getting write without response for characteristic from the peripheral side.

Android Notification Sound Causes Media Volume to Duck (Lower) & It Never Comes Back

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

How do you know if a UWP device has Chat/SMS Available?

Is there a C# method to call to see if Chat/SMS is available on a Windows10 device?

You can have the chat capabilities even on devices without a SIM card. Even Skype can also play the role of the default SMS app...
This link is giving you a sample
private async void ComposeSms(Windows.ApplicationModel.Contacts.Contact recipient, string messageBody, StorageFile attachmentFile, string mimeType)
{
var chatMessage = new Windows.ApplicationModel.Chat.ChatMessage();
chatMessage.Body = messageBody;
if (attachmentFile != null)
{
var stream = Windows.Storage.Streams.RandomAccessStreamReference.CreateFromFile(attachmentFile);
var attachment = new Windows.ApplicationModel.Chat.ChatMessageAttachment(mimeType, stream);
chatMessage.Attachments.Add(attachment);
}
var phone = recipient.Phones.FirstOrDefault<Windows.ApplicationModel.Contacts.ContactPhone>();
if (phone != null)
{
chatMessage.Recipients.Add(phone.Number);
}
await Windows.ApplicationModel.Chat.ChatMessageManager.ShowComposeSmsMessageAsync(chatMessage);
}
To check if the message is a SIM message, you should take a look at the property ChatMessage.IsSimMessage
var isSimMessage = chatMessage.isSimMessage;

You may try:
if (Windows.Foundation.Metadata.ApiInformation.IsTypePresent("Windows.ApplicationModel.Chat "))
{
}
Only if the method returns “true” the code inside it will be implemented, which indicates that SMS/Chat is available in this device.
Otherwise, your project will skip this part of code since the capability is unavailable in the device in case that your app may crash on these devices.
For more details, may check this document.

DeviceConnectionChangeTrigger - Value does not fall within the expected range

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.