Connect android phone to UWP application offline - c#

I am building a C# UWP Windows 8.1 application. I will like to know if there is a way I can connect my phone to my UWP Desktop app offline. I intended to transfer certain data and eliminate the time it takes for the devices to communicate with the server (- especially in cases of bad/no network here in Nigeria).

You can connect the two devices either using Bluetooth or Wi-fi direct. Bluetooth will probably be easier to setup. The process will be different for both platforms:
Bluetooth - UWP, Android
Wi-Fi Direct - UWP, Android
Bluetooth has broader support, but Wi-Fi direct may prove faster if you want "near real-time" performance.

Related

Discover Nearby Smartphone Devices on Android

Problem Statement
I am trying to make an application for Android that can detect nearby smartphone devices. I need to discover smartphone devices regardless of their connection to a WLAN or their operating system. The only requirement is that their bluetooth or wifi setting is enabled. I am trying to capture the MAC Address and maybe RSSI of these devices. An example of an application I am trying to emulate is Meshlium.
Methods Already Considered
Android Classic Bluetooth:
I have followed the guide to discover devices that aren't currently paired with my device.
The smartphones I am trying to discover need to be in "discovery" mode in order to be found. For most modern phones that means they need to be on their bluetooth settings page.
Android P2P (Wifi Direct):
I have followed the guide again and can't discover smartphones nearby.
Similar to bluetooth, both devices (mine and the device I am trying to find) need to be both trying to discover wifi direct devices.
Also it seems iOS doesn't support wifi direct anyways.
Google Nearby:
Nearby Connections works only with devices running an application that is using the nearby connections api. So only devices with the app currently running the advertising or discovery feature will be available for detection.
Wifi Network Service Discovery:
This lets me see devices that are currently advertising services on a network and not the actual devices themselves.
Device Specifications
The device I am using is running android version 6.0.1 and Model number rk3368-box. The device also has root permissions.
Question
Is there a way on my android device to discover the nearby smartphones with the only requirement being their wifi or bluetooth is enabled? Perhaps packet sniffing the probe requests of the devices? I have researched packet sniffing but can't find any solid resources for Android. Also I would love to be able to do so in c# and Xamarin.Android if possible.
Update
Is a custom ROM an option? I am not looking to make an application for the play store, but one for custom hardware. Perhaps when I enable the wifi hotspot on the device it logs the probe requests from the devices nearby and saves as a file to export later?
There is no way to do this. And there shouldn't be- unless I'm working with you (in which case multiple of the above will work) its a massive invasion of my privacy for you to be able to detect my device.
If you are able to find mac address for WLAN adaptor of a device than try to search for bluetooth devices having mac address same as WLAN adaptor but last digit changed by 1.
This way you can find a Bluetooth device even if it's visibility is hidden

How to communicate with android smartphone as BLE Gatt-Server from universal windows BLE Gatt-client?

Currently under Windows 10 it is not possible to connect to BLE device without pairing manually first. The devices that I want to handle as a server (peripheral in BLE communication concept) is android smartphone with OS version 5 and Bluetooth version 4.
I'm using two following samples, one for android gatt-server and another as UWP Gatt-client app.
https://github.com/devunwired/accessory-samples/tree/master/BluetoothGattPeripheral
https://github.com/Microsoft/Windows-universal-samples/blob/master/Samples/BluetoothLEClient
I have two problems about this issue. One is that, the client does not find the android-server for paring and connecting, unless the server (smartphone) be paired with windows via Bluetooth Setting App. The second problem is that after the paring although the client can see the server but I cannot connect to that, at this time I have an error on this line.
bluetoothLeDevice = await BluetoothLEDevice.FromIdAsync(rootPage.SelectedBleDeviceId);
Now how we can communicate with BLE android Gatt-Server through windows 10 universal apps as BLE Gatt-Client?

How can I determine whether I am connected to WiFi or a cellular network wpf?

I am working with a WPF app for tablets with Windows 8.1. The app connects to SAP. In the settings I have to implement an option for synchronisation to only occur over a WiFi network.
How can I determine if the tablet is connected to WiFi or a cellular network? From my research I have found ways to do this on XP and Vista or using Universal Apps. How can I implement this feature using WPF and Windows 8.1?

Can I use the Bluetooth serial port in Windows Phone 7.1 and up?

I want to develop an app for the Windows Phone app store that communicates with my car's OBD2 port via Bluetooth.
Long story short, the app will use the bluetooth serial port to send a hex value and retrieve the corresponding value in the ECU's register. There's an android app called Torque which does this.
I can't figure out how to use the serial port though. The only bluetooth functionality mentioned is high-level stuff like pushing objects, pairing, etc. But nothing about setting baud rates or writing to a specific COM port.
Is this possible on WP7/*? Or alternatively, how can I make this possible and get my app approved for distribution?
UPDATE: I haven't been able to get my hands on a WP8 device yet, so I can't verify whether or not this is possible using SSP.
As a bonus note in case you came here looking for alternatives: you can also NOT connect to ad-hoc wifi connections, so the wife-based OBD2 adapters are no good either. There is an ugly way of connecting to the latter which involves having a laptop in your car which is simultaneously connected in ad-hoc mode the the device and is also acting as a wifi hotspot. It is utterly impractical.
Using the Bluetooth Serial Port (SSP) is not possible with public APIs of Windows Phone 7.x. As you've kind of guessed already, the app will likely not be approved for the marketplace if private APIs are P/invoked or otherwise used.
Consider upgrading to Windows Phone 8 as the Bluetooth SSP is partially available there, see Nokias Developer site for example.

can c# be used for communicating mobile and pc?

As a minor project in my degree I would like to communicate mobile and pc .I am interested to communicate through bluetooth is it possible to do so in c#?
If possible please provide me list of application or hardware i would requiere in order to do so.
thanks in advance
If (and it's a big if based on the lack of information in your question) you mean "How do I write an app on my PC, using C#, that can communicate with a Windows Mobile device that is connected to my PC via ActiveSync or WMDC" then the answer is RAPI. A free, open-source managed wrapper for it is here.
Yes its possible if its with windows mobile phone or pocket pc with bluetooth. You need a bluetooth enabled computer and mobile phone. For dev you need to download the windows mobile 6 sdk.
Then developing of the communication between desktop app and mobile phone app, you can use the 32feet.Net is open source.
When you download it and installs (well it unpacks to program files folder) you will have the dll that you make reference to in Visual Studio. Also you will get some sample apps. One of them is a Bluetooth Chat that works in Desktop, Pocket PC and SmartPhone.
Another option you could use is set up a web service that acts like an intermediary between the device and your machine. One huge benefit of this is that no longer are you bound by the distance requirements of bluetooth.
Of course if you're trying to build some sort of proximity service (do z when item x is 3 meters from item y) then bluetooth is probably the way to go.

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