问题
This question is mostly answered by: Windows UWP connect to BLE device after discovery
I am writing a custom service and testing,for now, using a C#.NET WinForm on Windows 10 to connect to a Bluetooth Low Energy (BLE) device. I am using Framework 4.6.1. We are using a TI SmartRF06 Evaluation Board with a TI CC2650 BLE daughter card. Another developer is handling the Firmware of the Board.
Currently using methods similar to the reference answer above I am able to connect to an already bound BLE device. This device was manually bound and Windows did require me to enter a PIN. Since the device has no PIN simply entering "0" allowed the device to connect. Once connected, in this manner, I can get to all the GATT services and do what I need to do. So I have no issues with finding and getting a hold of a Advertising BLE device.
The issue is that how do I connect to BLE device that has not already been paired? I have gone through the net and found many examples of BLE code but nothing specific to showing how the pairing in code is done. Not sure I even need it to pair but Windows seems to only show my the GATT services on paired devices.
When I do this with unpaired device:
private void BleWatcherOnReceived(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs args)
{
var dev = await BluetoothLEDevice.FromBluetoothAddressAsync(args.BluetoothAddress);
// dev.DeviceInformation.Pairing.CanPair is true
// dpr.Status is Failed
DevicePairingResult dpr = await dev.DeviceInformation.Pairing.PairAsync(DevicePairingProtectionLevel.None);
var service = await GattDeviceService.FromIdAsync(dev.DeviceInformation.Id);
}
The result of dpr is always failed when device has not been manually paired. Which results in the GattDeviceServices being empty. But I am able to get the advertisement and the properties of the BLE device.
There is also this type of method to connect but I can't figure out how to use it:
var prslt = await device.DeviceInformation.Pairing.Custom.PairAsync(DevicePairingKinds.ProvidePin, DevicePairingProtectionLevel.None,IDevicePairingSettings);
IdeviceParingSettings is an Interface. Not sure what Class to use with it. I am thinking this is where I can set the PIN of "O" that I might need?
Has anyone had any luck pairing to a BLE device in Windows using C# where the BLE device has no security. Basically it should be wide open. I feel like I am missing something simple or this is simply not possible (which I have seen some posts claiming that is the case. Most of those were many years old).
I did try the methods described in the mentioned post without any difference in result.
Any help is appreciated. If you need more of the code please look at the link I provided at top as that is what I started with. I will be happy to provide all of my actual code if there is, perhaps, a sequence that I am doing out of place.
回答1:
I figured it out. I was on the right track.
After you connect using:
var dev = await BluetoothLEDevice.FromBluetoothAddressAsync(args.BluetoothAddress);
You need to do a custom Pairing:
var prslt = await device.DeviceInformation.Pairing.Custom.PairAsync(DevicePairingKinds.ProvidePin, DevicePairingProtectionLevel.None);
But that would simply give you an error. You must also create a device.DeviceInformation.Pairing.Custom.PairingRequested event handler.
So I created this handler:
private void handlerPairingReq(DeviceInformationCustomPairing CP, DevicePairingRequestedEventArgs DPR)
{
//so we get here for custom pairing request.
//this is the magic place where your pin goes.
//my device actually does not require a pin but
//windows requires at least a "0". So this solved
//it. This does not pull up the Windows UI either.
DPR.Accept("0");
}
Hooked it up just before the PairAsync call Like:
device.DeviceInformation.Pairing.Custom.PairingRequested += handlerPairingRequested;
Example code for the BlueToothAdvertisementWatcher Code that does my connection:
private BluetoothLEAdvertisementWatcher BTWatch = new BluetoothLEAdvertisementWatcher();
private void Inits()
{
BTWatch.Received += new TypedEventHandler<BluetoothLEAdvertisementWatcher, BluetoothLEAdvertisementReceivedEventArgs>(BtAddRx);
BTWatch.Start();
}
private async void BtAddRx(BluetoothLEAdvertisementWatcher bw, BluetoothLEAdvertisementReceivedEventArgs args)
{
GattCommunicationStatus srslt;
GattReadResult rslt;
bw.Stop();//Stop this while inside.
device = await BluetoothLEDevice.FromBluetoothAddressAsync(args.BluetoothAddress);
if (device.DeviceInformation.Pairing.IsPaired == false)
{
/* Optional Below - Some examples say use FromIdAsync
to get the device. I don't think that it matters. */
var did = device.DeviceInformation.Id; //I reuse did to reload later.
device.Dispose();
device = null;
device = await BluetoothLEDevice.FromIdAsync(did);
/* end optional */
var handlerPairingRequested = new TypedEventHandler<DeviceInformationCustomPairing, DevicePairingRequestedEventArgs>(handlerPairingReq);
device.DeviceInformation.Pairing.Custom.PairingRequested += handlerPairingRequested;
log("Pairing to device now....");
var prslt = await device.DeviceInformation.Pairing.Custom.PairAsync(DevicePairingKinds.ProvidePin, DevicePairingProtectionLevel.None);
log("Custom PAIR complete status: " + prslt.Status.ToString() + " Connection Status: " + device.ConnectionStatus.ToString());
device.DeviceInformation.Pairing.Custom.PairingRequested -= handlerPairingRequested; //Don't need it anymore once paired.
if (prslt.Status != DevicePairingResultStatus.Paired)
{ //This should not happen. If so we exit to try again.
log("prslt exiting. prslt.status=" + prslt.Status.ToString());// so the status may have updated. lets drop out of here and get the device again. should be paired the 2nd time around?
bw.Start();//restart this watcher.
return;
}
else
{
// The pairing takes some time to complete. If you don't wait you may have issues. 5 seconds seems to do the trick.
System.Threading.Thread.Sleep(5000); //try 5 second lay.
device.Dispose();
//Reload device so that the GATT services are there. This is why we wait.
device = await BluetoothLEDevice.FromIdAsync(did);
}
var services = device.GattServices;
//then more code to finish it up.
}
If you wish to disconnect just use:
await device.DeviceInformation.Pairing.UnpairAsync();
Sorry for the messy Code. If there is anyone that finds is useful or has question let me know. I could not find any WinForm examples of this code anywhere. Actually I could not find any code to show how to pair with PIN without the UI. So I hope this helps anyone that might get stuck.
来源：https://stackoverflow.com/questions/41420069/how-to-bind-manually-to-a-bluetooth-low-energy-device-in-a-winform-using-c