UWP BLE 广播状态已中止

Question

每当我从 UWP 应用程序启动 BluetoothLEAdvertisementWatcher 时，它的状态都会中止。在控制台应用程序中使用相同的功能是没有问题的（包括所需的库）。当我想与 BLE 设备配对时，我使用 UWP 应用程序中的 DeviceWatcher 没有问题。操作系统为Win10，使用VS2015 Community。

为了说明这个问题，我制作了一个 UWP 项目，其中包含蓝牙功能：

   <Capabilities>
   <Capability Name="internetClient" />
   <DeviceCapability Name="bluetooth" />
   </Capabilities>

MainPage 上有用于显示BluetoothLEAdvertisementWatcher 状态的Start、Stop 和View 按钮和TextBlock。代码呈现：

public sealed partial class MainPage : Page
    {
        private BluetoothLEAdvertisementWatcher watcher = null;

        public MainPage()
        {
            this.InitializeComponent();

            watcher = new BluetoothLEAdvertisementWatcher();
            watcher.ScanningMode = BluetoothLEScanningMode.Active;

            textBlock.Text = watcher.Status.ToString();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            watcher.Received += OnAdvertisementReceived;

            watcher.Stopped += OnAdvertisementWatcherStopped;
        }


        private void StopButton_Click(object sender, RoutedEventArgs e)
        {
            watcher.Stop();
        }

        private async void OnAdvertisementReceived(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs eventArgs)
        {

            await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
            {
                textBlock.Text = "rcvd" + watcher.Status.ToString();
            });
        }

        private async void OnAdvertisementWatcherStopped(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementWatcherStoppedEventArgs eventArgs)
        {
            // Notify the user that the watcher was stopped
            await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
            {
                textBlock.Text = "stopped:" + watcher.Status.ToString();
            });
        }

        private void buttonStart_Click(object sender, RoutedEventArgs e)
        {
            watcher.Start();
            textBlock.Text = watcher.Status.ToString();
        }
        private void buttonStop_Click(object sender, RoutedEventArgs e)
        {
            watcher.Stop();
            textBlock.Text = watcher.Status.ToString();
        }

        private void buttonView_Click(object sender, RoutedEventArgs e)
        {
            textBlock.Text = watcher.Status.ToString();
        }
    }

程序启动时，BluetoothLEAdvertisementWatcher 状态为 Created。按下 Start 按钮后，watcher 启动，但状态变为 Aborted，并触发事件 OnAdvertisementWatcherStopped（状态仍为 Aborted）。

对于克服这个问题有什么建议吗？或者可以做些什么来澄清问题？

更新

应用程序在不同的笔记本电脑上执行。结果是一样的，所以不是硬件问题。

网上有两个建议：

1. 启用蓝牙（Dmitry 在第一个回答中建议）

2. 检查功能（ https://keyoti.com/blog/bluetooth-low-energy-in-windows-10-troubleshooting-capabilities/)

没有提供结果。

补充说明：当 Stopped 的事件注册被移除时， (// watcher.Stopped += OnAdvertisementWatcherStopped;) 第一个结果是 Started。下一次单击按钮 View 将显示 Aborted。在很短的时间内，结果成功有效。

任何配置设置建议？

Answer 1

这个帖子帮助了我。

https://social.msdn.microsoft.com/Forums/windowshardware/en-US/5351a1f0-92f3-498b-a0c1-805d568cb55c/when-uwp-ble-advertising-watcher-is-started-its-status-is-aborted?forum=wdk

解决方案是为 uwp 应用启用“与设备同步”权限（设置->隐私->其他设备）。

Answer 2

我遇到了与 OP 类似的问题。在GattServiceProvider.StartAdvertising() 之后，属性GattServiceProvider.AdvertisementStatus 返回Aborted。我尝试了上述所有建议，但均未成功。

接下来，我从 https://github.com/microsoft/Windows-universal-samples/tree/main/Samples/BluetoothLE 下载了一个官方的 Microsoft 示例，构建并启动它并在那里体验了 Aborted 状态。

听起来很简单——我的开发笔记本电脑的简单重启解决了这个问题。下次我启动 Microsoft 示例时，它就可以工作了。

Answer 3

我认为您需要尝试在设备上启用蓝牙，同时获得“已中止”状态。

我为此添加了 LaunchBluetoothSettingsAsync() 方法。当 OnAdvertisementWatcherStopped 被触发且状态为 aborted 时调用它。

public sealed partial class MainPage : Page
{

    private BluetoothLEAdvertisementWatcher watcher = null;
    private IAsyncOperation<IUICommand> _bluetoothNotOnDialogOperation;

    public MainPage()
    {
        this.InitializeComponent();

        watcher = new BluetoothLEAdvertisementWatcher();
        watcher.ScanningMode = BluetoothLEScanningMode.Active;

        textBlock.Text = watcher.Status.ToString();
    }

    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        watcher.Received += OnAdvertisementReceived;

        watcher.Stopped += OnAdvertisementWatcherStopped;
    }


    private void StopButton_Click(object sender, RoutedEventArgs e)
    {
        watcher.Stop();
    }

    private async void OnAdvertisementReceived(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs eventArgs)
    {

        await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
        {
            textBlock.Text = "rcvd" + watcher.Status.ToString();
        });
    }

    private async void OnAdvertisementWatcherStopped(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementWatcherStoppedEventArgs eventArgs)
    {
        if (watcher .Status == BluetoothLEAdvertisementWatcherStatus.Aborted && _bluetoothNotOnDialogOperation == null)
        {
            MessageDialog messageDialog = new MessageDialog(
                "Do you wish to enable Bluetooth on this device?",
                "Failed to start Bluetooth LE advertisement watcher");

            messageDialog.Commands.Add(new UICommand("Yes",
                async command => { await LaunchBluetoothSettingsAsync(); }));

            messageDialog.Commands.Add(new UICommand("No",
                command => { watcher.Stop(); }));

            _bluetoothNotOnDialogOperation = messageDialog.ShowAsync();
        }
    }

    private void buttonStart_Click(object sender, RoutedEventArgs e)
    {
        watcher.Start();
        textBlock.Text = watcher.Status.ToString();
    }
    private void buttonStop_Click(object sender, RoutedEventArgs e)
    {
        watcher.Stop();
        textBlock.Text = watcher.Status.ToString();
    }

    private void buttonView_Click(object sender, RoutedEventArgs e)
    {
        textBlock.Text = watcher.Status.ToString();
    }

    private async Task LaunchBluetoothSettingsAsync()
    {
        await Launcher.LaunchUriAsync(new Uri("ms-settings-bluetooth:"));
    }
}