窗户UWP连接到后发现BLE装置 [英] Windows UWP connect to BLE device after discovery

问题描述

我用 BluetoothLEAdvertisementWatcher 来找到附近的BLE装置，它的工作好。找到他们后，我想连接和读/ GATT通过写入数据。但我无法弄清楚如何让后 BluetoothLEAdvertisement （https://msdn.microsoft.com/de-de/library/windows/apps/windows.devices.bluetooth.genericattributeprofile ）。

I'm using BluetoothLEAdvertisementWatcher to find nearby BLE devices and it's working well. After finding them I want to connect and read/write data via GATT. But I can't figure out how to use the API after getting the BluetoothLEAdvertisement (https://msdn.microsoft.com/de-de/library/windows/apps/windows.devices.bluetooth.genericattributeprofile).

public class Adapter
{
    private readonly BluetoothLEAdvertisementWatcher _bleWatcher = new BluetoothLEAdvertisementWatcher();

    public Adapter()
    {
        _bleWatcher.Received += BleWatcherOnReceived;
    }

    private void BleWatcherOnReceived(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs args)
    {       
        // how to connect?
        // I know, it's the wrong place to to this, but this is just an example
    }

    public void StartScanningForDevices(Guid[] serviceUuids)
    {
        _blewatcher.advertisementfilter.advertisement.serviceuuids.clear();
        foreach (var uuid in serviceuuids)
        {
            _blewatcher.advertisementfilter.advertisement.serviceuuids.add(uuid);
        }
        _blewatcher.start();
    }
}

我发现，使用<$ C样品$ C> DeviceInformation.FindAllAsync 而不是 BluetoothLEAdvertisementWatcher 但这些不工作/找到任何设备。

I've found Samples that are using DeviceInformation.FindAllAsync instead of BluetoothLEAdvertisementWatcher but these are not working / finding any device.

更新

周围的一些时间挖后，我发现下面的方法。但不幸的是，配对失败。该设备仅仅是一个带有BLE盾牌一个Arduino。我可以与Android和iOS绝对连接。因此，它必须能够以某种方式UWP。 ：/

After digging around some time, I found the following way. But unfortunately, the pairing fails. The device is just an Arduino with a BLE shield. I can definitely connect with Android and iOS. So it must be possible with UWP somehow. :/

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);
}

更新＃2

我现在可以发现和配对（不稳定，但确定目前如此），但

I'm now able to discover and pair (unstable, but ok for now), but

var service = await GattDeviceService.FromIdAsync(args.Id);

抛出以下异常

throws the following Exception

System.IO.FileNotFoundException：找不到
系统找不到指定的文件。 （异常来自HRESULT：0x80070002）。

System.IO.FileNotFoundException: The system cannot find the file specified. (Exception from HRESULT: 0x80070002)

我不知道为什么。

推荐答案

从杰森的正确答案继有关设备需要进行配对有他们的服务被发现，这里是一些示例代码来解决这个问题：

Following on from Jason's correct answer about devices needing to be paired to have their services be discovered, here is some sample code to address this:

    private void SetupBluetooth()
    {
        Watcher = new BluetoothLEAdvertisementWatcher { ScanningMode = BluetoothLEScanningMode.Active };
        Watcher.Received += DeviceFound;

        DeviceWatcher = DeviceInformation.CreateWatcher();
        DeviceWatcher.Added += DeviceAdded;
        DeviceWatcher.Updated += DeviceUpdated;

        StartScanning();
    }

    private void StartScanning()
    {
        Watcher.Start();
        DeviceWatcher.Start();
    }

    private void StopScanning()
    {
        Watcher.Stop();
        DeviceWatcher.Stop();
    }

    private async void DeviceFound(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs btAdv)
    {
        if (_devices.Contains(btAdv.Advertisement.LocalName))
        {
            await Dispatcher.RunAsync(CoreDispatcherPriority.Low, async () =>
            {
                Debug.WriteLine($"---------------------- {btAdv.Advertisement.LocalName} ----------------------");
                Debug.WriteLine($"Advertisement Data: {btAdv.Advertisement.ServiceUuids.Count}");
                var device = await BluetoothLEDevice.FromBluetoothAddressAsync(btAdv.BluetoothAddress);
                var result = await device.DeviceInformation.Pairing.PairAsync(DevicePairingProtectionLevel.None);
                Debug.WriteLine($"Pairing Result: {result.Status}");
                Debug.WriteLine($"Connected Data: {device.GattServices.Count}");
            });
        }
    }

    private async void DeviceAdded(DeviceWatcher watcher, DeviceInformation device)
    {
        if (_devices.Contains(device.Name))
        {
            try
            {
                var service = await GattDeviceService.FromIdAsync(device.Id);
                Debug.WriteLine("Opened Service!!");
            }
            catch
            {
                Debug.WriteLine("Failed to open service.");
            }
        }
    }

    private void DeviceUpdated(DeviceWatcher watcher, DeviceInformationUpdate update)
    {
        Debug.WriteLine($"Device updated: {update.Id}");
    }

这里要注意的关键事情是：

The key things to note here are:

• DeviceWatcher需要同时添加和更新的属性设置工作。


• 您需要捕捉试图审问时发生异常FileNotFound服务未配对，或尚未准备好。

这篇关于窗户UWP连接到后发现BLE装置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！