为什么GattDeviceService.FromIdASync()无法完成?

时间:2017-03-31 22:18:09

标签: c# bluetooth bluetooth-lowenergy windows-10-universal hm-10

我正在开发一个Windows 10 Universal Application,通过HM-10芯片与嵌入式系统进行通信。

我尝试了什么以及其他情况

芯片已设置,连接时没有问题。从这些设备的iPhone应用程序,我可以通过Arduino Serial窗口和iPhone应用程序进行双向消息传递。 我的计算机也可以看到它,并可以从Microsoft提供的示例应用程序连接到它。

在运行之前,它已在蓝牙设置中配对并连接。我也试过没有配对和连接,但是当时DeviceInformation没有发现它。

MainPage.xaml.cs

using System;
using System.Diagnostics;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using System.Threading.Tasks;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409

namespace App1
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    /// 

    public sealed partial class MainPage : Page
    {

        public List<string> deviceList = new List<string>();
        public MainPage()
        {
            this.InitializeComponent();
            Debug.WriteLine("A");
            var taskDevices = getDevices();
            Task.WaitAll(taskDevices);
            Debug.WriteLine("B");

        }
        public async Task<List<string>> getDevices()
        {
            Debug.WriteLine("C");
            foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(GattDeviceService.GetDeviceSelectorFromUuid(GattServiceUuids.GenericAccess), null))
            {
                Debug.WriteLine("D");
                Debug.WriteLine(di.Name);
                Debug.WriteLine(di.Id);
                Debug.WriteLine(di.IsEnabled);
                var bleDevice = await GattDeviceService.FromIdAsync(di.Id);
                Debug.WriteLine("E");
                // Add the dvice name into the list.  
               // deviceList.Add(bleDevice.Name);
            }
            return deviceList;
        }

        private void button_Click(object sender, RoutedEventArgs e)
        {

        }

        private void textBox_TextChanged(object sender, TextChangedEventArgs e)
        {

        }

我进行了搜索,我意识到清单需要增加蓝牙功能。

Package.appxmanifest

<?xml version="1.0" encoding="utf-8"?>
<Package xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10" xmlns:mp="http://schemas.microsoft.com/appx/2014/phone/manifest" xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10"  xmlns:m2="http://schemas.microsoft.com/appx/manifest/foundation/windows10" IgnorableNamespaces="uap mp">
  <Identity Name="acbf6f03-e62b-4d1e-8c25-9f649ca5af4c" Publisher="CN=Boomkin" Version="1.0.0.0" />
  <mp:PhoneIdentity PhoneProductId="acbf6f03-e62b-4d1e-8c25-9f649ca5af4c" PhonePublisherId="00000000-0000-0000-0000-000000000000" />
  <Properties>
    <DisplayName>App1</DisplayName>
    <PublisherDisplayName>Boomkin</PublisherDisplayName>
    <Logo>Assets\StoreLogo.png</Logo>
  </Properties>
  <Dependencies>
    <TargetDeviceFamily Name="Windows.Universal" MinVersion="10.0.0.0" MaxVersionTested="10.0.0.0" />
  </Dependencies>
  <Resources>
    <Resource Language="x-generate" />
  </Resources>
  <Applications>
    <Application Id="App" Executable="$targetnametoken$.exe" EntryPoint="App1.App">
      <uap:VisualElements DisplayName="Histamine Control Panel" Square150x150Logo="Assets\Square150x150Logo.png" Square44x44Logo="Assets\Square44x44Logo.png" Description="App1" BackgroundColor="transparent">
        <uap:DefaultTile Wide310x150Logo="Assets\Wide310x150Logo.png">
        </uap:DefaultTile>
        <uap:SplashScreen Image="Assets\SplashScreen.png" />
      </uap:VisualElements>
    </Application>
  </Applications>
  <Capabilities>
    <m2:DeviceCapability Name="bluetooth.genericAttributeProfile">
      <m2:Device Id="any">
        <m2:Function Type="serviceId:00001800-0000-1000-8000-00805f9b34fb"/>
      </m2:Device>
    </m2:DeviceCapability>
  </Capabilities>
</Package>

我尝试了很多其他版本,添加和删除了internetclient和蓝牙功能,没有任何成功。我目前猜测问题就在这里。

问题

正如问题所述,FromIdAsync部分没有返回任何内容。甚至不是null(正如我在这里看到的许多其他问题),它只是没有完成并且线程最终存在。

日志

A
C
D
HIST
\\?\BTHLEDevice#{00001800-0000-1000-8000-00805f9b34fb}_f45eabaaf694#8&2782425b&13&0006#{6e3bb679-4372-40c8-9eaa-4509df260cd8}
True

然后等了一会儿

The thread 0x3c6c has exited with code 0 (0x0).

谢谢,我真的很感激任何帮助。

1 个答案:

答案 0 :(得分:2)

你的问题在这里:

Task.WaitAll(taskDevices);

Blocking on asynchronous code causes a deadlock。正确的解决方案是使用async all the way

在您的特定情况下,您需要(同步,立即)以“加载”状态创建视图 - 无论您希望如何查看。然后,当异步代码完成时,视图更新为“已加载”状态。有关详细信息,请参阅我在async data binding上的MSDN文章。