UWP应用中如何响应蓝牙LE特征读取请求

我尝试按照这里的示例创建一个充当蓝牙LE外设的UWP应用程序： 但当尝试使用request.RespondWithValue响应特征读取请求时，我遇到一个异常： System.Exception:'对象已提交。（来自HRESULT:0x800001E的例外情况）'

如果我为特征设置了静态值，则正确读取该值

 ReadParameters.StaticValue = (new byte[] { 0x21 }).AsBuffer();

我在Windows 10 PC和Windows 10 IoT内核上都尝试过该代码，但得到了相同的异常

响应读取请求还需要其他什么吗

public sealed partial class MainPage : Page
{
    GattLocalCharacteristic _readCharacteristic;
    GattServiceProvider _serviceProvider;
    public MainPage()
    {
        this.InitializeComponent();
        SetupBle();
    }
    public async Task<bool> SetupBle()
    {
        GattServiceProviderResult result = await GattServiceProvider.CreateAsync(GattServiceUuids.Battery);
        if (result.Error == BluetoothError.Success)
        {
            _serviceProvider = result.ServiceProvider;
            var ReadParameters = new GattLocalCharacteristicParameters();
            ReadParameters.CharacteristicProperties = GattCharacteristicProperties.Read;
            ReadParameters.UserDescription = "Battery service";
            //ReadParameters.StaticValue = (new byte[] { 0x21 }).AsBuffer(); //if this is uncommented the static battery level value is read correctly
            GattLocalCharacteristicResult characteristicResult = await _serviceProvider.Service.CreateCharacteristicAsync(GattCharacteristicUuids.BatteryLevel, 
                ReadParameters);
            if (characteristicResult.Error != BluetoothError.Success)
            {
                return false;
            }
            _readCharacteristic = characteristicResult.Characteristic;
            _readCharacteristic.ReadRequested += _readCharacteristic_ReadRequested;
            GattServiceProviderAdvertisingParameters advParameters = new GattServiceProviderAdvertisingParameters
            {
                IsDiscoverable = true,
                IsConnectable = true
            };
            _serviceProvider.StartAdvertising(advParameters);
            return true;
        }
        return false;
    }
    private async void _readCharacteristic_ReadRequested(GattLocalCharacteristic sender, GattReadRequestedEventArgs args)
    {
        var writer = new DataWriter();
        writer.WriteByte(0x21);
        var request = await args.GetRequestAsync();
        request.RespondWithValue(writer.DetachBuffer());//will throw System.Exception: 'The object has been committed. (Exception from HRESULT: 0x8000001E)'
    }
}

公共密封部分类主页面：第页
{
GattLocalCharacteristic\u readCharacteristic；
GattServiceProvider\u服务提供商；
公共主页（）
{
this.InitializeComponent（）；
SetupBle（）；
}
公共异步任务SetupBle（）
{
GattServiceProviderResult=等待GattServiceProvider.CreateAsync（GattServiceUuids.Battery）；
if（result.Error==BluetoothError.Success）
{
_serviceProvider=result.serviceProvider；
var ReadParameters=新的GattLocalCharacteristicParameters（）；
ReadParameters.CharacteristicProperties=GattCharacteristicProperties.Read；
ReadParameters.UserDescription=“电池服务”；
//ReadParameters.StaticValue=（新字节[]{0x21}）.AsBuffer（）；//如果未注释，则静态电池电量值读取正确
GattLocalCharacteristicResult characteristicResult=Wait_serviceProvider.Service.CreateCharacteristicAsync（GattCharacteristicUuids.BatteryLevel，
读取参数）；
if（characteristicResult.Error！=BluetoothError.Success）
{
返回false；
}
_readCharacteristic=characteristicResult.Characteristic；
_readCharacteristic.ReadRequested+=\u readCharacteristic\u ReadRequested；
GattServiceProviderAdvertisingParameters advParameters=新的GattServiceProviderAdvertisingParameters
{
IsDiscoverable=true，
不可连接=真
};
_serviceProvider.startAvertising（advParameters）；
返回true；
}
返回false；
}
专用异步无效\u readCharacteristic\u ReadRequested（GattLocalCharacteristic发送方，GattReadRequestedEventArgs参数）
{
var writer=newdatawriter（）；
writer.WriteByte（0x21）；
var request=await args.GetRequestAsync（）；
request.RespondWithValue（writer.DetachBuffer（））；//将引发System.Exception:“该对象已提交。（来自HRESULT的异常：0x800001E）”
}
}

根据这里的评论 还有这里的评论 文件过时且不正确

此代码适用于我：

    private async void _readCharacteristic_ReadRequested(GattLocalCharacteristic sender, GattReadRequestedEventArgs args)
    {
        var deferral = args.GetDeferral();
        var writer = new DataWriter();
        writer.WriteByte(0x21);
        var request = await args.GetRequestAsync();
        request.RespondWithValue(writer.DetachBuffer());
        deferral.Complete();
    }