用C#开发一个 UWP BLUETOOTH BLE 扫描APP

什么是WINDOWS UWP

UWP即Windows 10 中的Universal Windows Platform简称。即Windows通用应用平台，在Win 10 Mobile/Surface(Windows平板电脑）/PC/Xbox/HoloLens等平台上运行，uwp不同于传统pc上的exe应用也跟只适用于手机端的app有本质区别。它并不是为某一个终端而设计，而是可以在所有windows10设备上运行。

微软在MWC 2015上首次展示了Win10统一平台战略的“代表作”：Win10通用应用（Windows10 Universal App）平台。在Win10中，所有设备将会运行在一个统一的Windows10系统核心之上。这样的设计使得一款应用可以在所有Win10设备上运行，今后Win10手机、平板电脑、笔记本电脑、PC、Xbox，甚至是3D全息眼镜HoloLens、巨屏触控Surface Hub和物联网设备例如Raspberry Pi 2等都不再有界限。新的通用平台允许新类型的Windows10通用应用真正实现一次编写、一套业务逻辑和统一的用户界面。应用在统一的Win10商店中将只会有一个安装包，而它将适用于所有Win10设备。^[1]在 Windows 10 Insider Preview 中的 Universal Windows Platform (UWP)借助 Windows 10 UWP 将在 Windows 应用中更上一层楼。UWP 会根据不同的设备类型使用相应的自适应 UI 控件，并使用运行 Windows 10 Insider Preview 的所有设备上必须具有的通用 API 集。简单的说，uwp就是通用应用的意思可以在电脑端，手机端，或其他设备通用。不用分别为不同的平台设计不同的软件。即一个软件就可以通吃。这估计现在是win10系统的一个软件发展趋势了。不管是开发者，还是使用者，都省事。

什么是蓝牙BLE

蓝牙低能耗(BLE)技术是低成本、短距离、可互操作的鲁棒性无线技术，工作在免许可的2.4GHz ISM射频频段。它从一开始就设计为超低功耗(ULP)无线技术。它利用许多智能手段最大限度地降低功耗。蓝牙低能耗技术采用可变连接时间间隔，这个间隔根据具体应用可以设置为几毫秒到几秒不等。另外，因为BLE技术采用非常快速的连接方式，因此平时可以处于“非连接”状态（节省能源），此时链路两端相互间只是知晓对方，只有在必要时才开启链路，然后在尽可能短的时间内关闭链路。

BLE技术的工作模式非常适合用于从微型无线传感器（每半秒交换一次数据）或使用完全异步通信的遥控器等其它外设传送数据。这些设备发送的数据量非常少（通常几个字节），而且发送次数也很少（例如每秒几次到每分钟一次，甚至更少）。

用Visual Studio 2015 开发一个BLE扫描程序

打开VISUAL STUDIO， 新建一个空白应用（通用WINDOWS）

将工程名称命名为 BleScanner

UWP平台处理蓝牙BLE的命名空间主要有下列几个

using Windows.Devices.Bluetooth.Advertisement;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;

我们将会用到的类是 BluetoothLEAdvertisementWatcher， 这个类负责扫描所有的BLE设备。

代码如下

using System;
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.Bluetooth.Advertisement;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;
using System.Diagnostics;
using System.Collections.ObjectModel;
using Windows.UI.Xaml.Shapes;
using Windows.UI;

//“空白页”项模板在 http://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409 上有介绍

namespace BleScanner
{
    /// <summary>
    /// 可用于自身或导航至 Frame 内部的空白页。
    /// </summary>
    public sealed partial class MainPage : Page
    {
        BluetoothLEAdvertisementWatcher bleWatvher = new BluetoothLEAdvertisementWatcher();
        DeviceWatcher devWatcher = DeviceInformation.CreateWatcher(BluetoothLEDevice.GetDeviceSelector(), null);

public MainPage()
        {

this.InitializeComponent();
            Bloos = new ObservableCollection<BlooDevice>();

startScanner();

}

private void startScanner()
        {
            bleWatvher.Received += BleWatvher_Received;
            bleWatvher.Stopped += BleWatvher_Stopped;
            devWatcher.Added += DevWatcher_Added;
            devWatcher.EnumerationCompleted += DevWatcher_EnumerationCompleted;
            devWatcher.Removed += DevWatcher_Removed;
            devWatcher.Stopped += DevWatcher_Stopped;
            devWatcher.Updated += DevWatcher_Updated;

bleWatvher.Start();
            Debug.WriteLine(Bloos.Count);
        }

private void DevWatcher_Updated(DeviceWatcher sender, DeviceInformationUpdate args)
        {

}

private void DevWatcher_Stopped(DeviceWatcher sender, object args)
        {
            devWatcher.Start();
        }

private void DevWatcher_Removed(DeviceWatcher sender, DeviceInformationUpdate args)
        {

}

private void DevWatcher_EnumerationCompleted(DeviceWatcher sender, object args)
        {

}

private void DevWatcher_Added(DeviceWatcher sender, DeviceInformation args)
        {

}

private void BleWatvher_Stopped(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementWatcherStoppedEventArgs args)
        {
            bleWatvher.Start();
        }

public ObservableCollection<BlooDevice> Bloos
        {
            get;
            set;
        }

private async void BleWatvher_Received(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs args)
        {
            await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
            {
                var exists = Bloos.Where(b => b.BluetoothAddress == args.BluetoothAddress).ToList();
                if (exists.Count == 0)
                {

Bloos.Add(new BlooDevice
                    {
                        Name = args.Advertisement.LocalName,
                        Rssi = args.RawSignalStrengthInDBm,
                        BluetoothAddress = args.BluetoothAddress
                    });

}
                else
                {

exists.ForEach(delegate (BlooDevice e)
                    {
                        e.BluetoothAddress = args.BluetoothAddress;
                        e.Name = args.Advertisement.LocalName;
                        e.Rssi = args.RawSignalStrengthInDBm;
                    });

}

});

}
    }
}

XAML 代码如下

<Page
    x:Class="BleScanner.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:BleScanner"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" RequestedTheme="Dark">

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <StackPanel  Orientation="Horizontal" Grid.Row="0" Margin="10,40,0,0"  >
            <Image Source="assets/ble_bw.png" Width="64" Height="64" VerticalAlignment="Center"/>
            <TextBlock Text="Ble Scanner" FontSize="24" FontWeight="Bold" VerticalAlignment="Center" Margin="20,0,0,0"></TextBlock>
        </StackPanel>
       
        <Border  Margin="10,10,10,10" Grid.Row="1" BorderBrush="AntiqueWhite" BorderThickness="1">

<ListView ItemsSource="{x:Bind Bloos}" >
                <ListView.Template>
                    <ControlTemplate>
                        <ScrollViewer>
                            <ItemsPresenter />
                        </ScrollViewer>

</ControlTemplate>
                </ListView.Template>
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="256"></ColumnDefinition>
                                <ColumnDefinition Width="128"></ColumnDefinition>
                                <ColumnDefinition Width="Auto"></ColumnDefinition>
                            </Grid.ColumnDefinitions>
                            <TextBlock Text="{Binding Name}" Grid.Column="0"/>
                            <TextBlock Text="{Binding Rssi}" Grid.Column="1"/>
                            <TextBlock Text="{Binding BluetoothAddressHex}" Grid.Column="2"/>

</Grid>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
        </Border >

</Grid>
</Page>

运行效果如图

源代码github地址

https://github.com/dingbig/BleScanner

相关的电路图

http://www.cirmall.com/user/3064949