Develop Reference

How to programmatically connect to wifi in Android

I've been searching on this for quite some time, and have found lots of solutions that ultimately use the Android GUI to prompt the end-user for connection/confirmation. We would like to present a user with a form and directly connect to the specified network. I understand from a security perspective why this is necessary, but in our case, it is a system app going on a fully managed Android device. It is not intended for general use in the Play store. We are using Xamarin, but I can adapt any Java/Kotlin code.
The closest I've found thus far is the following (using C#):
public void ConnectToWifi(string ssid, string password = "") {
var wifiNetworkSpecifier = new WifiNetworkSpecifier.Builder().SetSsid(ssid);
if (!string.IsNullOrEmpty(password))
wifiNetworkSpecifier.SetWpa2Passphrase(password);
var networkRequest = new NetworkRequest.Builder().AddTransportType(TransportType.Wifi)?
.SetNetworkSpecifier(wifiNetworkSpecifier.Build())?.Build();
if (networkRequest is null)
return;
var theNetworkCallback = new TheNetworkCallback();
var connectivityManager = (ConnectivityManager?)MainActivity.Current.ApplicationContext?
.GetSystemService(Context.ConnectivityService);
connectivityManager?.RequestNetwork(networkRequest, theNetworkCallback);
}
It sorta works, but does prompt the end-user, and my understanding, this approach is deprecated and doesn't work well in newer versions of Android. We're hoping for a solution that works in Android 11.
I'm even fine if there's a solution to write directly to wifi files on the OS. I've seen various solutions to manually populate entries via ADB, but I'm having a tough time adapting that to Xamarin/Java (can't seem to access the /data/misc/wifi directories). Again, this is intended for use exclusively on our own managed devices.

I have a blog post about this topic here: https://blog.ostebaronen.dk/2020/11/android-11-wifi.html
Android Network API is not the greatest thing to work with as there are pitfals depending on the API level the code runs on.
From Android 10 and up a lot of the Network stuff has been restricted for "privacy" reasons, so you cannot work around not asking the user for input, unless the device is rooted or your App is set up as Device Admin.
For Android 11, there is a new API to present a system dialog and allow the user to save and connect to a network. This will look something like:
You can launch this through an Intent called android.settings.WIFI_ADD_NETWORKS:
var intent = new Intent(
"android.settings.WIFI_ADD_NETWORKS");
var bundle = new Bundle();
bundle.PutParcelableArrayList(
"android.provider.extra.WIFI_NETWORK_LIST",
new List<IParcelable>
{
new WifiNetworkSuggestion.Builder()
.SetSsid(ssid)
.SetWpa2Passphrase(password)
.Build()
});
intent.PutExtras(bundle);
StartActivityForResult(intent, AddWifiSettingsRequestCode);
You can then get the result in your Activity overriding OnActivityResult and fetching the result like so:
if (requestCode == AddWifiSettingsRequestCode)
{
if (data != null && data.HasExtra(
"android.provider.extra.WIFI_NETWORK_RESULT_LIST"))
{
var extras =
data.GetIntegerArrayListExtra(
"android.provider.extra.WIFI_NETWORK_RESULT_LIST")
?.Select(i => i.IntValue()).ToArray() ?? new int[0];
if (extras.Length > 0)
{
var ok = extras
.Select(GetResultFromCode)
.All(r => r == Result.Ok);
// if ok is true, BINGO!
return;
}
}
}
I have a repository here with the full sample: https://github.com/Cheesebaron/Android11WiFi
From using this in the wild, I've found that this API does not work nicely with some OEMs such as OnePlus and Huawei. Some of these either restrict or the System Settings App simply crashes due to a misconfiguration on their part. For those I fall back to the API's introduced in Android 10.

Is the Android Wifi-API really so broken on Android 10+?

I'm working on a Wifi auto connect feature and I am shocked how broken that API is.
I'm using now 5 different APIs and I still don't get it in a way the user would expect it.
I have a setting to enable wifi auto connection on Android 10+ I'll try this:
Check if I hold the ACCESS_WIFI_STATE permission with:
appOpsManager.unsafeCheckOp("android:change_wifi_state", Process.myUid(), context.packageName) == AppOpsManager.MODE_ALLOWED
When I own the permission I go on with 2. if not I continue with 6.
When I hold the permission I'll check on Android 11+ if from a previous run my wifi suggestion was saved wifiManager.networkSuggestions.isNotEmpty() if that is true I check which Wifi I'm currently connected with see step x. On lower levels I skip this and go to step 3
I use the wifi suggestion API with the WifiNetworkSuggestion.Builder() and suggest the user my wifi with
val status = wifiManager.addNetworkSuggestions(listOf(suggestion))
// Strage bug: On first usage the return value is always SUCCESS
val success = status == WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS
When the user accepts my suggestion I'm fine so far. I cannot verify on Android 10 if my suggestion was accepted. On Android 11 this is possible (see step 2). However I still don't know if the device actually connected with the wifi. So I go to step 7
When the user rejected my suggestion I'm almost out of the game I can never ask the user again (well technically there is a well hidden feature where you can switch the permission, but no user will ever find it). On Android 10 I can just check if I'm connected with the right wifi, well at least theoretically (see step 7).
On Android 11+ I can fallback to the Settings.ACTION_WIFI_ADD_NETWORKS intent which can always add Wifis (with the downside that the user can share the wifi password)
I need to verify if the steps before worked and the user is actually connected to the desired wifi. To do so I already own the permissions ACCESS_WIFI_STATE, ACCESS_NETWORK_STATE, ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION. However the ConnectivityManager API don't return the actual SSID, that drives me crazy.
If the user is not connected to the right wifi I would try to use the Settings.Panel.ACTION_WIFI action to let the user to connect to the right wifi
To summarize that:
I use the WifiNetworkSuggestion API
I fallback to Settings.ACTION_WIFI_ADD_NETWORKS where possible
I try to verify if the user is currently connected to the right wifi
I try to assist the user to conenct to the right wifi (or even turn wifi on) with the Settings.Panel.ACTION_WIFI action
Is that really such a mess or is there a easier way?
I'm currently accessing the SSID like this:
private val currentSsid: String?
get() =
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val wifiInfo = connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)?.transportInfo as? WifiInfo
wifiInfo?.ssid
} else {
wifiManager.connectionInfo?.ssid
}
Based on Unable to get WIFI SSID using onCapabilitiesChanged in Android 12 I think that way I access the value is not supported. I get currently the value "<unknown ssid>".

Well just a half answer, but it might help anyway. Here is how I get the current SSID of the user (you need to hold the location permission):
fun updateSsid(networkCapabilities: NetworkCapabilities) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
currentSsid = (networkCapabilities.transportInfo as? WifiInfo)?.ssid?.trim('"')
}
}
wifiCallback = when {
Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
object: ConnectivityManager.NetworkCallback(FLAG_INCLUDE_LOCATION_INFO) {
override fun onCapabilitiesChanged(network: Network, networkCapabilities: NetworkCapabilities) {
updateSsid(networkCapabilities)
}
}
}
Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q -> {
object: ConnectivityManager.NetworkCallback() {
override fun onCapabilitiesChanged(network: Network, networkCapabilities: NetworkCapabilities) {
updateSsid(networkCapabilities)
}
}
}
else -> null
}
wifiCallback?.let {
fragment.lifecycle.addObserver(object: DefaultLifecycleObserver {
override fun onResume(owner: LifecycleOwner) {
connectivityManager.registerNetworkCallback(request, it)
}
override fun onPause(owner: LifecycleOwner) {
connectivityManager.unregisterNetworkCallback(it)
}
})
}
So basically aspects of your code need to check apis for the levels <10, 10, 11 and 12. What a mess.
This might be quiet handy if you want the user to pick the configured wifi:
fun showWifiDialog() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
try {
fragment.startActivity(Intent(android.provider.Settings.Panel.ACTION_WIFI))
} catch (e: Exception) {
// ignored
}
}
}

CompanionDeviceManager without using an intent chooser and scanning

I already have mac addresses of the Bluetooth device that I need to connect to. I do not wish to ask for any location permission. when my app is launched I need to scan and connect to the Bluetooth device using the mac address that is specified. Companion Device pairing that has been introduced in the latest android version.. I do not wish to open a chooser and get the callback result in onActivityResult. If there is any other way I could route all the scanning done by the Companion Device.
deviceManager.associate(pairingRequest,
object : CompanionDeviceManager.Callback() {
// Called when a device is found. Launch the IntentSender so the user
// can select the device they want to pair with.
override fun onDeviceFound(chooserLauncher: IntentSender) {
startIntentSenderForResult(chooserLauncher,
SELECT_DEVICE_REQUEST_CODE, null, 0, 0, 0)
}
override fun onFailure(error: CharSequence?) {
// Handle the failure.
}
}, null)
in the below code if there is any way I could use a different mechanism so that my scanning can happen and I get the result somewhere and it does not ask for a dialog box for the user to enter.
startIntentSenderForResult(chooserLauncher,
SELECT_DEVICE_REQUEST_CODE, null, 0, 0, 0)
or is there any way to use bluetooth functionality without asking for location permission?

If you already know the mac address there is no need to scan. You can use
BluetoothDevice device = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(macAddress)

val scanFilter = ScanFilter.Builder().setDeviceAddress(staticBtMac).build()
val ledeviceFilter: BluetoothLeDeviceFilter = BluetoothLeDeviceFilter.Builder()
.setScanFilter(scanFilter)
.build()
Before you create the pairingRequest above in AssociationRequest.Builder
You would
val pairingRequest: AssociationRequest = AssociationRequest.Builder()
.addDeviceFilter(ledeviceFilter)
.setSingleDevice(true)
This will not list devices but just a permission pop up dialog with ->
"Allow 'Appname' to access your 'BT ADV Device name'" [Allow] [Don't Allow] buttons. It looks slightly different depending on if its Pixel or Samsung or other phone but it comes down to simple yes/no.
There is also the
..setSelfManaged(true)
But this involves far more complexity and even more interaction with the framework.
If you really want to get into it you can see the actual code at https://cs.android.com/

Reconnecting call with WebRtc after network offline Android

I try to reconnect after network offline.
I success to re connecting to call if the network fail in receiver side.
But i don't success to do it if network fail in the caller side.
I try to re -init the web WebRTC client , it's don't work.
Also try to create new offer , it's also don't work.
Do anyone know how to handle re connect in android with WebRTC?

My case was slightly different since I ran into this issue while trying to implement WIFI > DATA network connection transition but I'm confident that this should work for you as well.
The solution for me was to recreate the offer and add a new constraint IceRestart in MediaConstraints and set it to true:
val mediaConstraint = MediaConstraints().apply {
mandatory.add(MediaConstraints.KeyValuePair("IceRestart", "true"))
}
Then you just add the param in createOffer() (which you should probably have already) like so:
peerConnection.createOffer(object : SdpObserver() {
override fun onCreateSuccess(p0: SessionDescription?) {
// normal implementation
}
},mediaConstraint)
Hope it helps :)

Android 5.0 (L) - Check data Roaming Setting

I have a problem identifying the data roaming setting in Android L. In previous versions of Android, I was able to access either Settings.Secure or Settings.Global (depending on the Android version), and get the setting.
But now, on Android L, this no longer works. Whether data roaming is on or off, the return from the Settings.Global is always 0.
Android L supports multi SIM out of the box, so, a new manager was created to handle this: SubscriptionManager. This subscription manager, handles the several settings of the several SIM cards in the form of SubInfoRecord classes. I can retrieve the settings per SIM card.
However, the dataRoaming filed inside that class is always 0 as well.
Does anyone know how can this be achieved on the new API?
My app is a system app that comes embedded in the phones from factory so, I should be able to access all the APIs available.
However, I've spent a long time looking in the source code but I found nothing. In the Settings.Global class there's no indication that that setting no longer works on Android.
Does anyone have a clue on where this setting was moved to?
Thanks in advance!

Check this DevicePolicyManager.setGlobalSetting
as from documentation this can only be called by device owner app.
Is your app is installed as device owner ?
If not you can check the following links
Create device owner without root
Create device owner with root
Do something like this
DevicePolicyManager manager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
manager.setGlobalSetting(<Admin_Component>, Settings.Global.DATA_ROAMING, <value>);
Admin_Component: Component instance
Value: "0" for disable or "1" for enable

Since android 5.0, android supports multiple SIM cards, use the following code to check for data roaming.
public static boolean isDataRoamingEnabled(Context context) {
SubscriptionManager subMngr = (SubscriptionManager) context.getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE);
int id = SubscriptionManager.getDefaultDataSubscriptionId();
if (ActivityCompat.checkSelfPermission(context, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
return false;
}
SubscriptionInfo ino = subMngr.getActiveSubscriptionInfo(id);
if (ino == null)
return false;
return ino.getDataRoaming() == 1;
}