我试图从Windows 10读取Android外围设备广播的ServiceUuid,如下所示:
private void OnAdvertisementReceived(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs advertisementArg)
{
Debug.WriteLine(" serviceUuids for advertisement " + advertisementArg.Advertisement.ServiceUuids.Count);
foreach(Guid guid in advertisementArg.Advertisement.ServiceUuids)
{
Debug.WriteLine("uuid is " + guid.ToString() + " address is " +advertisementArg.BluetoothAddress+ " name is "+ advertisementArg.Advertisement.LocalName);
}
}
但是,当收到来自Android外围设备的广告时,ServiceUuids列表的大小始终为0.
这很奇怪,因为服务数据已正确放置在广告的BluetoothLeAdvertisementDataSection中:
IList<BluetoothLEAdvertisementDataSection> dataSection = advertisementArg.Advertisement.DataSections;
foreach (BluetoothLEAdvertisementDataSection ad in dataSection)
{
if (ad.Data.Length > 0)
{
DataReader dataReader = DataReader.FromBuffer(ad.Data);
byte[] bytes = new byte[ad.Data.Length];
dataReader.ReadBytes(bytes);
if (bytes.Length > 0)
{
string data = System.Text.Encoding.UTF8.GetString(crcBytes, 0, crcBytes.Length);
Debug.WriteLine("ANDROID DEVICE FOUND " + data);
}
}
}
因此,只是缺少了ServiceUuid.
服务数据像这样在Android外设中添加:
AdvertiseData.Builder dataBuilder = new AdvertiseData.Builder();
dataBuilder.addServiceData(new ParcelUuid(bluetoothUuid), advertiseData.getBytes());
解决方法:
Android数据是“服务数据”部分类型,而不是“服务UUID列表”部分类型.服务UUIDs属性仅适用于服务UUID列表,不适用于服务数据.
对于蓝牙广告(Beacons)可用于发送包含通用唯一标识符(UUID)的信息包,该包的数据部分可由应用程序开发人员定制.
我们应该能够解析BluetoothLEManufacturerData中的数据以获得UUID.
例如:
private void OnAdvertisementReceived(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs eventArgs)
{
var manufacturerSections = eventArgs.Advertisement.ManufacturerData;
if (manufacturerSections.Count > 0)
{
var manufacturerData = manufacturerSections[0];
var data = new byte[manufacturerData.Data.Length];
using (var reader = DataReader.FromBuffer(manufacturerData.Data))
{
reader.ReadBytes(data);
}
}
}
有一个大约BluetoothAdvertisement的官方样本,它显示了如何使用Bluetooth Advertisement API发送和接收Bluetooth Low Energy广告.