在windows 下用unity添加蓝牙搜索功能需要什么第三方库

在 Windows 下使用 Unity 添加蓝牙搜索功能，需要使用 Windows.Devices.Bluetooth 命名空间提供的 API。不需要额外安装第三方库。

以下是使用 Windows.Devices.Bluetooth API 搜索蓝牙设备的示例代码：

using UnityEngine;
using System.Collections.Generic;
using System.Threading.Tasks;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.Advertisement;

public class BluetoothScanner : MonoBehaviour
{
    private BluetoothLEAdvertisementWatcher watcher;
    private List<BluetoothDevice> devices = new List<BluetoothDevice>();

    private async void Start()
    {
        // 初始化 watcher
        watcher = new BluetoothLEAdvertisementWatcher();
        watcher.Received += Watcher_Received;

        // 开始搜索
        watcher.Start();

        // 等待搜索完成
        await Task.Delay(5000);

        // 停止搜索
        watcher.Stop();
    }

    private void Watcher_Received(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs args)
    {
        // 处理搜索到的设备
        BluetoothDevice device = new BluetoothDevice(args.BluetoothAddress, args.RawSignalStrengthInDBm);
        if (!devices.Contains(device))
        {
            devices.Add(device);
            Debug.Log("Found device: " + device.Name);
        }
    }

    private void OnDestroy()
    {
        // 释放 watcher
        if (watcher != null)
        {
            watcher.Stop();
            watcher.Received -= Watcher_Received;
            watcher = null;
        }
    }
}

public class BluetoothDevice
{
    public ulong Address { get; private set; }
    public string Name { get; private set; }
    public short SignalStrength { get; private set; }

    public BluetoothDevice(ulong address, short signalStrength)
    {
        Address = address;
        SignalStrength = signalStrength;
        Name = "Unknown";
    }

    public override bool Equals(object obj)
    {
        if (obj is BluetoothDevice other)
        {
            return Address == other.Address;
        }
        return false;
    }

    public override int GetHashCode()
    {
        return Address.GetHashCode();
    }
}

在代码中，我们创建了一个 BluetoothLEAdvertisementWatcher 对象，并在 Start() 方法中调用 Start() 方法开始搜索。当搜索到设备时，Watcher_Received() 方法会被调用并处理搜索到的设备。最后，在 OnDestroy() 方法中调用 Stop() 方法停止搜索。

需要注意的是，使用 Windows.Devices.Bluetooth API 搜索蓝牙设备需要在 Unity 中使用 .NET 4.x API，而不是 Unity 默认的 .NET 3.5 API。可以在 Unity 编辑器中选择 Edit -> Project Settings -> Player -> Other Settings，然后将 Scripting Runtime Version 设置为 .NET 4.x Equivalent。