在 Windows 中列出来自 CPython 的已连接 BLE 设备

Question

我正在将 Linux 上的 Python 代码运行移植到 Windows，并且需要实现 2 个简单的特定于平台的功能（通过 [=11 处理） =] 在 Linux 下调用):

列出所有当前连接的 BLE 设备
- 例如list_connected() → [('F9:18:AF:E7:9D:40','HeadPhones'),('aa:93:88:1e:03','SmartWatch')]
强制断开连接的设备
- 例如disconnect('F9:18:AF:E7:9D:40',timeout=2)

由于 bleak，其余 BLE 功能已经跨平台。

我只有很少的 Windows 经验，尤其是最近的 API。我环顾四周，不明白 WinRT（Windows 运行时 API）是 UWP（通用 Windows 平台）的一部分，可以从 CPython 通过 pythonnet 和 winrt 包；这是正确的实施方式吗？

感谢提示。

Answer 1

以下是列出和断开设备的主要代码片段（完整代码已通过电子邮件发送给 OP）。我没有包括异常处理和从异步到同步的包装，因为这是 Python 特有的，对其他人来说可能并不那么重要。

import winrt.windows.foundation as wf
import winrt.windows.devices.bluetooth as bt
import winrt.windows.devices.enumeration as denum

import asyncio # to support async / await because winrt doesn't have sync versions of BLE functions

# the naming in the Python wrapper looks a bit messy, underscores mixed up with PascalCase
# another caveat is that we have to call the specific override with the second argument `[]`
# otherwise Python winrt wrapper gets confused with multiple versions of find_all_async
dev_infos = await denum.DeviceInformation.find_all_async(bt.BluetoothLEDevice.get_device_selector(), [])

id_name_pairs = []
    
for dev_info in dev_infos:
    # getting the device itself to access it's "connected" status
    le_device = await bt.BluetoothLEDevice.from_id_async(dev_info.id);
    
    if le_device is None: # enumerator sometimes has stale devices; this can also happen when you unplug BLE dongle
        continue
        
    # in status context, Microsoft calls it "CONNECTED", but later, when disconnecting, it needs "unpair"
    # and there is no any "disconnect" function. Microsoft is messy in this regard
    if le_device.connection_status == bt.BluetoothConnectionStatus.CONNECTED:
        id_name_pairs.append((le_device.device_id, le_device.name));

重要 - Microsoft 通过其完整 ID 而不是 BLE 地址来识别 BLE 设备。如果我们希望稍后能够断开设备，我们必须知道 ID。如果我们不将 ID 存储在任何地方并按地址断开连接，我们将不得不再次运行枚举并按地址查找 ID。

从设备 ID 中轻松提取 BLE 地址：

addressed_devices = list(map(lambda dev: (dev[0][-17:], dev[1]), id_name_pairs))

要断开已知 ID 的设备：

le_device = await bt.BluetoothLEDevice.from_id_async(dev_id)
await le_device.device_information.pairing.unpair_async()

要求：Windows10，2018 年 10 月更新或更高版本，Python for Windows，版本 3.7 或更高版本，pip，版本 19 或更高版本。

使用 pip install winrt 获取 Python winrt 包装器库。

总而言之，一项乍一看似乎微不足道的任务，由于 .NET / Python 命名和覆盖差异以及 Microsoft 的 pairing/connection 导致了一些 head-scratching执行;很容易与不能使用 BLE 配对信息的经典蓝牙 BR/EDR API 混淆。

在 Windows 中列出来自 CPython 的已连接 BLE 设备

Listing connected BLE devices from CPython in Windows

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