如何修复“Gatt 写入特性失败” xamarin 形式的例外？

如何解决如何修复“Gatt 写入特性失败” xamarin 形式的例外？

我正在尝试在通知后在 BLE 中执行 GATT 写操作，我从服务器获取值。当没有先前的 GATT 操作（如通知）时，写入操作可以正常工作。所以这是我通过通知读取值

的代码

public async Task ReadConfigData(ICharacteristic characteristics)
        {
            if (characteristics != null)
            {
                try
                {
                    await _adapter.ConnectToDeviceAsync(_device);
                   
                        characteristics.ValueUpdated += (o,e) =>
                    {
                          Device.BeginInvokeOnMainThread(async () =>
                         {
                        //var readvalue2 = characteristics.Value;
                        var bytes = e.Characteristic.Value;
                        //var readvalue = await characteristics.ReadAsync();
                        BLEresultnew = System.Text.Encoding.UTF8.GetString(bytes);

                        Console.WriteLine(BLEresultnew);
                        //if(BLEresultnew.Contains("start"))
                        //{
                        concat += BLEresultnew;
                             //}
                         });
                    };
                    await characteristics.StartUpdatesAsync();
                   
                }

                catch (Exception ex)
                {
                    Console.WriteLine(ex);
                }
                
            

这就是我如何进行写操作

 public async task WriteDataAsync(String data)
        {
            if (_characteristicsBLE != null)
            {
                try
                {
                    
                       // await _adapter.ConnectToDeviceAsync(_device);
                        byte[] senddata = Encoding.UTF8.GetBytes(data);
                    int start = 0;
                    while (start < senddata.Length)
                    {
                        
                            int chunkLength = Math.Min(20,senddata.Length - start);
                        byte[] chunk = new byte[chunkLength];
                        Array.Copy(senddata,start,chunk,chunkLength);
                        Device.BeginInvokeOnMainThread(async () =>
                        {
                            await Task.Delay(300);
                            await _characteristicsBLE.WriteAsync(chunk);
                        });
                        start += 20;
                        
                    }

                   
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex);
                }
            }

我什至在主线程中调用了写操作以避免任何线程问题。但我仍然收到 GATT 错误。我不知道如何解决这个问题，有什么建议吗？