using GoogleApiClient I am able to get location in this way:
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
#Override
public void onConnected(Bundle connectionHint) {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
mLatitudeText = String.valueOf(mLastLocation.getLatitude());
Log.d("the lat is",mLatitudeText);
mLongitudeText = String.valueOf(mLastLocation.getLongitude());
Log.d("the lon is",mLongitudeText);
}
}
but this does not work for android TV application. Neither onConnected nor onConnectionFailed is called. I did not find any documentation too.
The Android developer documentation on handling TV hardware states:
TVs have a different purpose from other devices, and so they do not have hardware features that other Android-powered devices often have. For this reason, the Android system does not support the following features for a TV device:
GPS - android.hardware.location.gps
That might be tripping you up.
The documentation offers some hints on solutions:
TVs are stationary, indoor devices, and do not have built-in global positioning system (GPS) receivers. If your app uses location information, you can still allow users to search for a location, or use a static location provider such as a zip code configured during the TV device setup.
Related
I am trying scan the Bluetooth devices using 32feet.NET library using the following code.
private void Button_Click(object sender, RoutedEventArgs e)
{
BluetoothClient client = new BluetoothClient();
foreach (BluetoothDeviceInfo bdi in client.DiscoverDevices())
{
System.Diagnostics.Debug.WriteLine(bdi.DeviceName + " " + bdi.DeviceAddress);
}
}
The above code returns list of available Bluetooth devices in WPF application. But when I use the same code in UWP application I am getting the following exception.
System.Runtime.InteropServices.COMException: 'A method was called at an unexpected time.
When I tried to use the async/await as per the suggestion given here to fix this exception, I am not able to use async/await in collections. So I used Task.FromResult method as below then also the exception is not fixed.
private async void Button_Click(object sender, RoutedEventArgs e)
{
BluetoothClient client = new BluetoothClient();
var dev = await Task.FromResult(client.DiscoverDevices());
foreach (BluetoothDeviceInfo bdi in dev)
{
System.Diagnostics.Debug.WriteLine(bdi.DeviceName + " " + bdi.DeviceAddress);
}
}
Can someone help me why the same code works in WPF application but not in UWP application?
Unable to Discover Bluetooth Devices in UWP application but works in WPF application
I'm afraid the third part library does not support UWP platform, if you want to discover Bluetooth device in UWP platform, we suggest you use DeviceWatcher class to enumerate all Bluetooth device.
Here is official code sample that you could refer and here is official document.
UWP applications are containerised (sandboxed). This means that UWP applications cannot communicate with the kernel and other parts of the operating system directly. The only way a UWP application can communicate with the operating system is through Windows 10/11 API calls. Example: await Windows.System.Launcher.LaunchUriAsync(new Uri("ms-settings"));
There exist a couple of workarounds, one notable example is to download the UWP SDK in a WPF application and use UWP libraries within that respective WPF application.
Look here: https://www.thomasclaudiushuber.com/2019/04/26/calling-windows-10-apis-from-your-wpf-application/
I want to use Apple and Google's new APIs to support Covid contact tracing as desribedin this API document. But when I try to use these APIs in XCode, the classes are not found:
let request = CTSelfTracingInfoRequest()
How do I enable these APIs?
The APIs for iOS are restricted. While you can write code against the ExposureNotifcation framework using XCode 11.5 and iOS 13.5, you can't run the code even in a simulator without Apple granting you a provisioning profile with the com.apple.developer.exposure-notification entitlement. And Apple is only giving that entitlement to developers associated with government health agencies after a manual approval process.
Below is more information on what you can do without special permission from Apple.
iOS releases prior to 13.5 disallowed transmitting the Exposure Notification Service beacon bluetooth advertising format in the specification. Starting with 13.5, advertising is possible only by the operating system -- 3rd party apps cannot emit that advertisement without using higher-level APIs.
Starting with iOS 13.5, Apple also blocks direct detection of this beacon format by third party apps, forcing them to use higher-level APIs. Earlier versions of iOS do allow detection of this beacon format.
Android, however, is another story.
While Google has similarly restricted use of these APIs in Google Play Services to API keys with special permissions granted from Google, Android versions 5.0+ allows 3rd party apps to both sending and detect the Exposure Notification Service beacon advertisement that the bluetooth specification envisions:
Using the free and open-source Android Beacon Library 2.17+, you can transmit this beacon like this:
String uuidString = "01020304-0506-0708-090a-0b0c0d0e0f10";
Beacon beacon = new Beacon.Builder()
.setId1(uuidString)
.build();
// This beacon layout is for the Exposure Notification Service Bluetooth Spec
BeaconParser contactDetectionBeaconParser = new BeaconParser()
.setBeaconLayout("s:0-1=fd6f,p:-:-59,i:2-17");
BeaconTransmitter beaconTransmitter = new
BeaconTransmitter(getApplicationContext(), contactDetectionBeaconParser);
beaconTransmitter.startAdvertising(beacon
And scan for it like this:
BeaconManager beaconManager = BeaconManager.getInstanceForApplication(this);
beaconManager.getBeaconParsers().add(new BeaconParser().setBeaconLayout("s:0-1=fd6f,p:-:-59,i:2-17"));
...
beaconManager.startRangingBeaconsInRegion(new Region("All Exposure Notification Service beacons", null));
...
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {
for (Beacon beacon: beacons) {
Log.i(TAG, "I see an Exposure Notification Service beacon with rolling proximity identifier "+beacon.getId1());
}
}
On Android, the above transmission and detection is possible even in the background. See library documentation for details.
The ability to transmit and receive Exposure Notification Service beacons is built into the BeaconScope Android app. You can use this as a tool to help test any apps you build.
You can read more in my blog post which shows you how to build your own app to do this.
As for iOS, while transmission is impossible as of this writing, you can scan for these beacons on iOS 13.4.x and earlier with code like this:
let exposureNotificationServiceUuid = CBUUID(string: "FD6F")
centralManager?.scanForPeripherals(withServices: [exposureNotificationServiceUuid], options: [CBCentralManagerScanOptionAllowDuplicatesKey: true])
...
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
if let advDatas = advertisementData[CBAdvertisementDataServiceDataKey] as? NSDictionary {
if let advData = advDatas.object(forKey: CBUUID(string: "FD6F")) as? Data {
let hexString = advData.map { String(format: "%02hhx", $0) }.joined()
let proximityId = String(hexString.prefix(32))
let metadata = hexString.suffix(8)
NSLog("Discovered Exposure Notification Service Beacon with Proximity ID\(proximityId), metadata \(metadata) and RSSI \(RSSI)")
}
}
}
Beware, however, that Apple blocked this from working as of iOS 13.5 beta 2. The didDiscover method above is never called for advertisements with the Exposure Notification Service UUID.
Full Disclosure: I am the lead developer on the Android Beacon Library open source project and the author of the BeaconScope app built on this library.
EDIT April 26, 2020: Updated answer above to link to the revised 1.1 version of the Exposure Notification Service Bluetooth Spec, to update naming conventions from that change, and to revise code samples to show the metadata.
EDIT April 30, 2020: Updated answer based on Apple's release of iOS 13.5 beta 2 and XCode 11.5 beta, and the fact that Apple now blocks 3rd party apps from detecting the Exposure Notification Service beacon.
EDIT June 2, 2020: Updated answer based on Apple's final release of iOS 13.5 and Google's release of Google Play Services.
You also may use other open-source contact tracing protocols like Apple/Google's.
For instance OpenCovidTrace – it is an open source implementation of the Google/Apple protocol with minor changes, or DP-3T – it is a protocol proposed by european science community.
I created a test Xamarin.Forms project, tabbed app, with support for iOS, Android, and UWP. The app with the boilerplate starter code builds and and runs correctly on all 3 platforms.
Am trying to test receiving UDP broadcast in the app. The UDP broadcast is being sent from another machine on the same subnet (have tested broadcasting from another machine and from the same machine, results are the same). If I run a standalone, unmanaged UDP listener test tool on this machine (one we wrote internally), I can see all the messages coming through from the other machine.
I added the code (shown below) to the Xamarin.Forms project and ran the UWP build on this machine. What I'm seeing is that in the debug output I get the "started receiving" message, then nothing else. I'm not actually receiving the messages (or at least, the callback is not being invoked). I checked netstat and can see that when my Xamarin.Forms app is running, it is bound to the specified UDP port. But my OnUdpDataReceived never gets called.
EDIT: I double-clicked the UWP project's Package.appxmanifest file in solution explorer which brought up a UI and in that I checked "Capabilities >> Internet (Client & Server)" thinking it was a permissions thing, but this did not help.
EDIT: I verified connectivity by creating two console projects, a sender and a receiver. The sender just loops forever sending a test UDP broadcast each second. The receiver uses the same code shown here. These projects work as expected. So the same receiver code is working in the console project, but not in the Xamarin.Forms project.
First, a simple UDP receiver class.
public class BaseUdpReceiver
{
private UdpClient _udpClient;
public BaseUdpReceiver()
{
}
public void Start()
{
_udpClient = new UdpClient()
{
ExclusiveAddressUse = false,
EnableBroadcast = true
};
_udpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
_udpClient.Client.Bind(new IPEndPoint(IPAddress.Any, Constants.Network.SOME_CONSTANT_PORT_INTEGER));
_udpClient.BeginReceive(OnUdpDataReceived, _udpClient);
Debug.WriteLine($">>> started receiving");
}
private static void OnUdpDataReceived(IAsyncResult result)
{
Debug.WriteLine($">>> in receive");
var udpClient = result.AsyncState as UdpClient;
if (udpClient == null)
return;
IPEndPoint remoteAddr = null;
var recvBuffer = udpClient.EndReceive(result, ref remoteAddr);
Debug.WriteLine($"MESSAGE FROM: {remoteAddr.Address}:{remoteAddr.Port}, MESSAGE SIZE: {recvBuffer?.Length ?? 0}");
udpClient.BeginReceive(OnUdpDataReceived, udpClient);
}
}
Then, the code in App.xaml.cs which uses this class.
public partial class App : Application
{
private BaseUdpReceiver _udpReceiver;
public App()
{
InitializeComponent();
DependencyService.Register<MockDataStore>();
MainPage = new MainPage();
_udpReceiver = new BaseUdpReceiver();
_udpReceiver.Start();
}
protected override void OnStart()
{
}
protected override void OnSleep()
{
}
protected override void OnResume()
{
}
}
version info
Visual Studio 2019 Enterprise v16.4.5
Xamarin 16.4.000.322 (d16-4#ddfd842)
Windows 10 64-bit v1909 (OS Build 18363.657)
Microsoft.NETCore.UniversalWindowsPlatform, v6.2.9
NETStandard.Library, v2.0.3
Xamarin.Essentials, v1.5.0
Xamarin.Forms, v4.5.0.356
Got it working for both UWP and Android with help from MS support.
Note that the code provided in the original post is correct and works, given the following considerations.
UWP
Due to network isolation with UWP, you can't broadcast and receive on the same machine, while this works fine with the console apps, it doesn't work with Xamarin.Forms UWP, so the trick is you just have to broadcast from a different machine
Need to adjust Package.appxmanifest >> Capabilities settings
On 2 machines (a wifi laptop and wired desktop), I found it was sufficient to have "Internet (Client)" and "Internet (Client & Server)" checked
On a 3rd desktop machine with 2 NICs, one plugged in and one unplugged, it still didn't work with the above options, it was necessary to also check the "Private Networks (Client & Server)"
Android
The emulator appears to create its own subnet, you can see this by checking the emulator's network settings, it clearly isn't on the same subnet as the desktop machine on which its running
As a result, you can't get UDP broadcasts in the Android emulator in an easy way (aside from some sort of forwarding scheme which I did not experiment with)
Verified that with a physical Android tablet (tested with Samsung Galaxy Tab A 8"), it works and I'm able to receive UDP broadcasts
Note that on Android I didn't have to change any permissions from the defaults as with UWP, it worked without issue
iOS
As of yet, have not tested on a physical iOS device, I have an iPhone, but I'm using a cloud Mac build server so can't test on my device
When it comes time to deal with iOS, it looks like I'll probably need to get a local Mac
getting NETWORK_COMMUNICATION when calling coreRouter.calculateRoute
not sure what url is't trying to reach ,
so can not test connection issue.
coreRouter.calculateRoute(routePlan, new CoreRouter.Listener() {
#Override
public void onCalculateRouteFinished(List<RouteResult> list,
RoutingError routingError) {
the routingError returns NETWORK_COMMUNICATION .
Using phone to test and am connected to the wifi network and can view webpages via the chrome browser
NETWORK_COMMUNICATION with SDK usually indicates a connectivity issue with HERE Servers, the connectivity issue could occur
if there are issues accessing HERE Servers by the SDK, make sure all *here.com are whitelisting if you device is using any proxy or
The map data on the device is very old and it is not being maintained anymore and make sure the device map is updated using the corresponding method in SDK MapLoader.checkForMapDataUpdate() and MapLoader.performMapDataUpdate()
I am trying to create a QT based application that scan and connect WiFi networks. I am using this example as a reference code.
Is it possible to assign static IP for the WiFi connection using QNetworkConfiguration or any related class ?
How to authenticate the networks that are password protected ?
thanks in advance......
I have created a net work session using the below code set..
void BearerMonitor::createNewSessionFromQml(QString ssid)
{
QList<QNetworkConfiguration> allConfigurations = manager.allConfigurations();
while (!allConfigurations.isEmpty()) {
QNetworkConfiguration config = allConfigurations.takeFirst();
if(config.name()==ssid)
createSessionFor(config);
}
}
SessionWidget::SessionWidget(const QNetworkConfiguration &config, QObject *parent):QObject(parent)
{
session = new QNetworkSession(config, this);
session->open();
}
No you can't. At least not with just Qt APIs.
Please read this and in particular this. QNetworkConfiguration is just a facility to manage network configurations. Editing such configurations is demanded to native code / OS interactions. From the second link:
Note that the QNetworkConfiguration object only provides limited information about the configuration details themselves. It's main purpose is to act as a configuration identifier through which link layer connections can be created, destroyed and monitored.
Even the "start/stop network interfaces" claim is not entirely true since such a feature is available only in certain OSs (not the mobile ones). See the "Platform capabilities" section of the second link for more details about that.
The same reasoning applies to the password question. Once a network is registed in the OS with the corresponding password (because of native code or the user physically registering it) a new configuration is available to the NetworkConfigurationManager, granted that the list of configurations is updated via updateConfigurations(). The new configuration contains the password but you can't edit it from Qt APIs.
Native code is the only solution, as said. Still, Apple does not want you to mess up with WiFi programatically since private APIs for that cannot be used in iOS > 5.1 (the oldest version supported by Qt as for Qt 5.4).