用C#写一个蓝牙4.0搜索、连接、接收、发送功能的demo

以下是一个简单的C#蓝牙4.0搜索、连接、接收、发送功能的示例代码。请注意，此代码仅供参考，具体实现可能因操作系统版本、硬件设备等因素而有所不同。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Threading;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;

namespace BluetoothDemo
{
    class Program
    {
        private static readonly Guid ServiceUUID = new Guid("0000fff0-0000-1000-8000-00805f9b34fb");
        private static readonly Guid CharacteristicUUID = new Guid("0000fff1-0000-1000-8000-00805f9b34fb");

        static async Task Main(string[] args)
        {
            Console.WriteLine("Searching for Bluetooth devices...");
            var deviceInformationCollection = await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector());
            if (deviceInformationCollection.Count == 0)
            {
                Console.WriteLine("No devices found.");
                return;
            }

            Console.WriteLine("Select a device to connect:");
            for (int i = 0; i < deviceInformationCollection.Count; i++)
            {
                Console.WriteLine($"{i}: {deviceInformationCollection[i].Name} - {deviceInformationCollection[i].Id}");
            }

            int selectedIndex = int.Parse(Console.ReadLine());

            var selectedDevice = await BluetoothLEDevice.FromIdAsync(deviceInformationCollection[selectedIndex].Id);

            Console.WriteLine($"Connecting to device {selectedDevice.Name}...");

            var gattServicesResult = await selectedDevice.GetGattServicesAsync();
            if (gattServicesResult.Status != GattCommunicationStatus.Success)
            {
                Console.WriteLine($"Failed to get GATT services. Status: {gattServicesResult.Status}");
                return;
            }

            var service = gattServicesResult.Services.FirstOrDefault(s => s.Uuid == ServiceUUID);
            if (service == null)
            {
                Console.WriteLine($"Service {ServiceUUID} not found.");
                return;
            }

            var characteristicsResult = await service.GetCharacteristicsAsync();
            if (characteristicsResult.Status != GattCommunicationStatus.Success)
            {
                Console.WriteLine($"Failed to get characteristics. Status: {characteristicsResult.Status}");
                return;
            }

            var characteristic = characteristicsResult.Characteristics.FirstOrDefault(c => c.Uuid == CharacteristicUUID);
            if (characteristic == null)
            {
                Console.WriteLine($"Characteristic {CharacteristicUUID} not found.");
                return;
            }

            Console.WriteLine("Connected!");

            characteristic.ValueChanged += Characteristic_ValueChanged;

            var status = await characteristic.WriteClientCharacteristicConfigurationDescriptorAsync(GattClientCharacteristicConfigurationDescriptorValue.Notify);
            if (status != GattCommunicationStatus.Success)
            {
                Console.WriteLine($"Failed to configure characteristic for notifications. Status: {status}");
                return;
            }

            Console.WriteLine("Waiting for notifications...");

            while (true)
            {
                await Task.Delay(1000);
            }
        }

        private static void Characteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
        {
            var data = Encoding.UTF8.GetString(args.CharacteristicValue.ToArray());
            Console.WriteLine($"Received data: {data}");
        }
    }
}

在这个示例中，我们首先搜索可用的蓝牙设备，然后让用户选择要连接的设备。连接后，我们获取设备的GATT服务和特性，并将特性配置为可以接收通知。最后，我们等待特性的值改变事件，并读取从设备接收到的数据。

请注意，此示例在Windows 10操作系统上测试通过，需要使用Visual Studio开发环境和Windows.Devices.Bluetooth.GenericAttributeProfile和Windows.Devices.Bluetooth命名空间。同时，还需要确保操作系统支持蓝牙4.0，并且硬件设备已经正确安装和配置。