连接到 Windows 10 上的 BLE 外围设备

Question

我尝试连接到 BLE 外围设备。首先，我看广告：

watcher = new BluetoothLEAdvertisementWatcher { ScanningMode = BluetoothLEScanningMode.Active };
watcher.Received += WatcherOnReceived;
watcher.Start();

在 WatcherOnReceived 回调中我尝试创建 BluetoothLEDevice

public async void WatcherOnReceived(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs btAdv)
{
    BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromBluetoothAddressAsync(btAdv.BluetoothAddress);
}

但是，我总是在 WatcherOnReceived 回调中得到 bleDevice == null。为什么以及如何解决它？在 UWP 应用程序中创建 BLE 设备的正确方法是什么？然后我需要连接到该设备，发现它的 GATT 服务和特性，在其中一些上启用通知并读/写其中一些。

Answer 1

这个问题的答案很简单——不要在 Windows 10 上使用 BLE。API 不起作用或行为随机，并且完全没有文档记录。我喜欢每个人都在谈论物联网是下一次工业革命，而微软在 BLE 存在 6 年后没有工作的 BLE API。

Answer 2

如果您希望能够连接到以前未配对的 BLE 设备，例如使用带有蓝牙 LE 选择器的 DeviceWatcher，请参阅 https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/DeviceEnumerationAndPairing 中的示例 8 和 9。

否则，您需要先在系统的蓝牙配对设置中进行配对，然后才能从 FromBluetoothAddressAsync 检索 BluetoothLEDevice。

Answer 3

您可以查看WatcherOnReceived() 中的设备信息，以确保该设备是您要连接的设备。这样做：

public async void WatcherOnReceived(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs btAdv)
{
    if (btAdv.Advertisement.LocalName == "SensorTag")
    {
        BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromBluetoothAddressAsync(btAdv.BluetoothAddress);
    }    
}

使用您自己的 BLE 设备名称而不是“SensorTag”。

注意：您需要事先配对您的 BLE 设备（以编程方式，如 DeviceEnumerationAndPairing 示例或 PC 的设置应用程序，如下图所示。）。