bh003- Blazor hybrid / Maui 使用蓝牙BLE快速教程

1. 建立工程 bh003_ble

源码

2. 添加 nuget 包

<PackageReference Include="BlazorHybrid.Maui.Permissions" Version="0.0.2" />
<PackageReference Include="BootstrapBlazor" Version="7.*" />
<PackageReference Include="Densen.Extensions.BootstrapBlazor" Version="7.*" />

BlazorHybrid.Maui.Permissions 因为源码比较长,主要是一些检查和申请权限,BLE权限相关代码,就不占用篇幅列出,感兴趣的同学直接打开源码参考

顺便打开可空 <Nullable>enable</Nullable>

3. 添加蓝牙权限

安卓

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
  <application android:allowBackup="true" android:icon="@mipmap/appicon" android:roundIcon="@mipmap/appicon_round" android:supportsRtl="true"></application>
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
  <uses-permission android:name="android.permission.INTERNET" />
  <!--蓝牙-->
  <uses-feature android:name="android.hardware.bluetooth_le" android:required="true" />

  <!-- csproj文件指定SupportedOSPlatformVersion android 28.0 可以继续使用安卓9的权限 -->
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
  <uses-permission android:name="android.permission.BLUETOOTH"/>
  <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

  <!-- csproj文件指定SupportedOSPlatformVersion android 31.0 使用安卓12的权限 -->
  <!-- Android 12以下才需要定位权限，Android 9以下官方建议申请ACCESS_COARSE_LOCATION -->

  <!--<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" android:maxSdkVersion="30"/>
	<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" android:maxSdkVersion="30"/>
	<uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30"/>
	<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" android:maxSdkVersion="30"/>-->

  <!-- Android 12在不申请定位权限时，必须加上android:usesPermissionFlags="neverForLocation"，否则搜不到设备 -->
  <uses-permission android:name="android.permission.BLUETOOTH_SCAN" android:usesPermissionFlags="neverForLocation"/>

  <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
  <!--蓝牙 END-->
</manifest>

iOS

Info.plist

    <key>UIBackgroundModes</key>
    <array>
        <string>bluetooth-central</string>
        <string>bluetooth-peripheral</string>
    </array>
    <key>NSBluetoothPeripheralUsageDescription</key>
    <string>此应用程序需要访问您的蓝牙。请根据要求授予权限.</string>
    <key>NSBluetoothAlwaysUsageDescription</key>
    <string>此应用程序需要访问您的蓝牙。请根据要求授予权限.</string>

以下是完整文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>LSRequiresIPhoneOS</key>
    <true/>
    <key>UIDeviceFamily</key>
    <array>
        <integer>1</integer>
        <integer>2</integer>
    </array>
    <key>UIRequiredDeviceCapabilities</key>
    <array>
        <string>arm64</string>
    </array>
    <key>UISupportedInterfaceOrientations</key>
    <array>
        <string>UIInterfaceOrientationPortrait</string>
        <string>UIInterfaceOrientationLandscapeLeft</string>
        <string>UIInterfaceOrientationLandscapeRight</string>
    </array>
    <key>UISupportedInterfaceOrientations~ipad</key>
    <array>
        <string>UIInterfaceOrientationPortrait</string>
        <string>UIInterfaceOrientationPortraitUpsideDown</string>
        <string>UIInterfaceOrientationLandscapeLeft</string>
        <string>UIInterfaceOrientationLandscapeRight</string>
    </array>
    <key>XSAppIconAssets</key>
    <string>Assets.xcassets/appicon.appiconset</string>
    <key>UIBackgroundModes</key>
    <array>
        <string>bluetooth-central</string>
        <string>bluetooth-peripheral</string>
    </array>
    <key>NSBluetoothPeripheralUsageDescription</key>
    <string>此应用程序需要访问您的蓝牙。请根据要求授予权限.</string>
    <key>NSBluetoothAlwaysUsageDescription</key>
    <string>此应用程序需要访问您的蓝牙。请根据要求授予权限.</string>

</dict>
</plist>

Windows

Package.appxmanifest

4. 编辑 Index.html 文件,引用 BootstrapBlazor UI 库.

完整文件

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover" />
    <title>bh003_ble</title>
    <base href="/" />
    <link href="_content/BootstrapBlazor.FontAwesome/css/font-awesome.min.css" rel="stylesheet">
    <link href="_content/BootstrapBlazor/css/bootstrap.blazor.bundle.min.css" rel="stylesheet">
    <link href="_content/BootstrapBlazor/css/motronic.min.css" rel="stylesheet">
    <link href="css/app.css" rel="stylesheet" />
    <link href="bh003_ble.styles.css" rel="stylesheet" />
</head>

<body>

    <div class="status-bar-safe-area"></div>

    <div id="app">Loading...</div>

    <div id="blazor-error-ui">
        An unhandled error has occurred.
        <a href="" class="reload">Reload</a>
        <a class="dismiss"><i class="fa-solid fa-xmark"></i></a>
    </div>

    <script src="_content/BootstrapBlazor/js/bootstrap.blazor.bundle.min.js"></script>
    <script src="_framework/blazor.webview.js" autostart="false"></script>

</body>

</html>

5. 添加 BootstrapBlazorRoot 组件

Main.razor 文件添加 BootstrapBlazorRoot 组件

6. 添加命名空间引用

_Imports.razor

@using BootstrapBlazor.Components

7. 添加服务

MauiProgram.cs

添加

            builder.Services.AddDensenExtensions();
            builder.Services.ConfigureJsonLocalizationOptions(op =>
            {
                // 忽略文化信息丢失日志
                op.IgnoreLocalizerMissing = true;

            });
            builder.Services.AddSingleton<BluetoothLEServices>();
            builder.Services.AddScoped<IStorage, StorageService>();

完整文件

using bh003_ble.Data;
using Microsoft.Extensions.Logging;
using BlazorHybrid.Maui.Shared;
using BootstrapBlazor.WebAPI.Services;

namespace bh003_ble
{
    public static class MauiProgram
    {
        public static MauiApp CreateMauiApp()
        {
            var builder = MauiApp.CreateBuilder();
            builder
                .UseMauiApp<App>()
                .ConfigureFonts(fonts =>
                {
                    fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                });

            builder.Services.AddMauiBlazorWebView();

#if DEBUG
		builder.Services.AddBlazorWebViewDeveloperTools();
		builder.Logging.AddDebug();
#endif

            builder.Services.AddSingleton<WeatherForecastService>();
            builder.Services.AddDensenExtensions();
            builder.Services.ConfigureJsonLocalizationOptions(op =>
            {
                // 忽略文化信息丢失日志
                op.IgnoreLocalizerMissing = true;

            });
            builder.Services.AddSingleton<BluetoothLEServices>();
            builder.Services.AddScoped<IStorage, StorageService>();

            return builder.Build();
        }
    }
}

8. 添加代码后置文件 Pages/Index.razor.cs

Index.razor.cs

using BlazorHybrid.Core.Device;
using BlazorHybrid.Maui.Shared;
using BootstrapBlazor.Components;
using BootstrapBlazor.WebAPI.Services;
using Microsoft.AspNetCore.Components;
using System.Diagnostics.CodeAnalysis;

namespace bh003_ble.Pages;

public partial class Index : IAsyncDisposable
{
    [Inject, NotNull]
    BluetoothLEServices? MyBleTester { get; set; }
    [Inject, NotNull] protected IStorage? Storage { get; set; }
    [Inject, NotNull] protected ToastService? ToastService { get; set; }

    public void SetTagDeviceName(BleTagDevice ble)
    {
        MyBleTester.TagDevice = ble;

        if (!isInit)
        {
            MyBleTester.OnMessage += OnMessage;
            MyBleTester.OnDataReceived += OnDataReceived;
            MyBleTester.OnStateConnect += OnStateConnect;
            isInit = true;
        }
    }

    public event Action<string>? OnMessage;
    public event Action<string>? OnDataReceived;
    public event Action<bool>? OnStateConnect;

    bool isInit = false;

    public async Task<List<BleDevice>?> StartScanAsync() => await MyBleTester.StartScanAsync();

    public async Task<List<BleService>?> ConnectToKnownDeviceAsync(Guid deviceID, string? deviceName = null) => await MyBleTester.ConnectToKnownDeviceAsync(deviceID, deviceName);

    public async Task<List<BleCharacteristic>?> GetCharacteristicsAsync(Guid serviceid) => await MyBleTester.GetCharacteristicsAsync(serviceid);

    public async Task<string?> ReadDeviceName(Guid? serviceid, Guid? characteristic) => await MyBleTester.ReadDeviceName(serviceid, characteristic);

    public async Task<byte[]?> ReadDataAsync(Guid characteristic) => await MyBleTester.ReadDataAsync(characteristic);

    public async Task<bool> SendDataAsync(Guid characteristic, byte[] ary) => await MyBleTester.SendDataAsync(characteristic, ary);

    public async Task<bool> DisConnectDeviceAsync() => await MyBleTester.DisConnectDeviceAsync();


    public Task<bool> BluetoothIsBusy() => MyBleTester.BluetoothIsBusy();




    private bool IsScanning = false;
    private List<BleDevice>? Devices { get; set; }
    private List<BleService>? Services { get; set; }
    private List<BleCharacteristic>? Characteristics { get; set; }
    private string? ReadResult { get; set; }
    private string? Message { get; set; } = "";

    BleTagDevice BleInfo { get; set; } = new BleTagDevice();

    private List<SelectedItem> DemoList { get; set; } = new List<SelectedItem>() { new SelectedItem() { Text = "测试数据", Value = "" } };
    private List<SelectedItem> DeviceList { get; set; } = new List<SelectedItem>();
    private List<SelectedItem> ServiceidList { get; set; } = new List<SelectedItem>();
    private List<SelectedItem> CharacteristicList { get; set; } = new List<SelectedItem>();

    private Dictionary<string, object>? IsScanningCss => IsScanning ? new() { { "disabled", "" }, } : null;

    bool IsAutoConnect { get; set; }
    bool IsAuto { get; set; }
    bool IsInit { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            await Init();
        }
    }

    async Task<bool> Init()
    {
        try
        {

            if (IsInit) return true;

            if (await BluetoothIsBusy())
            {
                await ToastService.Warning("蓝牙正在使用中，请稍后再试");
                return false;
            }
            OnMessage += Tools_OnMessage;
            OnDataReceived += Tools_OnDataReceived;
            OnStateConnect += Tools_OnStateConnect;
            SetTagDeviceName(BleInfo);
            IsInit = true;

            StateHasChanged();

            var deviceID = await Storage.GetValue("bleDeviceID", string.Empty);
            if (!string.IsNullOrEmpty(deviceID))
            {
                BleInfo.Name = await Storage.GetValue("bleDeviceName", string.Empty);
                BleInfo.DeviceID = Guid.Parse(deviceID);
                var serviceid = await Storage.GetValue("bleServiceid", string.Empty);
                if (!string.IsNullOrEmpty(serviceid)) BleInfo.Serviceid = Guid.Parse(serviceid);
                var characteristic = await Storage.GetValue("bleCharacteristic", string.Empty);
                if (!string.IsNullOrEmpty(characteristic)) BleInfo.Characteristic = Guid.Parse(characteristic);
                var auto = await Storage.GetValue("bleAutoConnect", string.Empty);
                if (auto == "True")
                {
                    IsAuto = true;
                    await AutoRead();

                }
            }
            return true;

        }
        catch (Exception ex)
        {
            System.Console.WriteLine(ex.Message);
        }
        return false;
    }


    private async Task AutoRead()
    {
        Services = null;
        Characteristics = null;
        Message = "";
        ReadResult = "";
        Devices = new List<BleDevice>() { new BleDevice() { Id = BleInfo.DeviceID, Name = BleInfo.Name } };
        DeviceList = new List<SelectedItem>() { new SelectedItem() { Text = BleInfo.Name, Value = BleInfo.DeviceID.ToString() } };
        IsAutoConnect = true;
        await OnDeviceSelect();
        IsAutoConnect = false;
    }

    private async Task OnStateChanged(bool value)
    {
        await Storage.SetValue("bleAutoConnect", value.ToString());
    }

    private void Tools_OnStateConnect(bool obj)
    {

    }

    private async void Tools_OnDataReceived(string message)
    {
        ReadResult = message;
        Tools_OnMessage(message);
        await InvokeAsync(StateHasChanged);
    }

    private async void Tools_OnMessage(string message)
    {
        if (Message != null && Message.Length > 500) Message = Message.Substring(0, 500);
        Message = $"{message}\r\n{Message}";
        await InvokeAsync(StateHasChanged);
    }


    //扫描外设
    private async void ScanDevice()
    {
        if (!await Init()) return;

        IsScanning = true;
        Devices = null;
        Services = null;
        Characteristics = null;
        Message = "";
        ReadResult = "";
        DeviceList = new List<SelectedItem>() { new SelectedItem() { Text = "请选择...", Value = "" } };

        //开始扫描
        Devices = await StartScanAsync();

        if (Devices != null)
        {
            Devices.ForEach(a => DeviceList.Add(new SelectedItem() { Active = IsAutoConnect && a.Id == BleInfo.DeviceID, Text = a.Name ?? a.Id.ToString(), Value = a.Id.ToString() }));
        }

        IsScanning = false;

        //异步更新UI
        await InvokeAsync(StateHasChanged);
    }

    //连接外设
    private async Task OnDeviceSelect(SelectedItem item)
    {
        if (IsAutoConnect || item.Value == "") return;
        BleInfo.Name = item.Text;
        BleInfo.DeviceID = Guid.Parse(item.Value);
        await OnDeviceSelect();
    }

    private async Task OnDisConnectDevice()
    {
        if (await DisConnectDeviceAsync())
            await ToastService.Success("断开成功");
        else
            await ToastService.Error("断开失败");
    }

    private async Task OnDeviceSelect()
    {

        Services = null;
        Characteristics = null;
        Message = "";
        ReadResult = "";
        ServiceidList = new List<SelectedItem>() { new SelectedItem() { Text = "请选择...", Value = "" } };
        //连接外设
        Services = await ConnectToKnownDeviceAsync(BleInfo.DeviceID, BleInfo.Name);
        if (Services != null)
        {
            Services.ForEach(a => ServiceidList.Add(new SelectedItem() { Active = IsAutoConnect && a.Id == BleInfo.Serviceid, Text = a.Name ?? a.Id.ToString(), Value = a.Id.ToString() }));
            await Storage.SetValue("bleDeviceID", BleInfo.DeviceID.ToString());
            await Storage.SetValue("bleDeviceName", BleInfo.Name ?? "上次设备");
            if (BleInfo.Serviceid != Guid.Empty && IsAutoConnect)
            {
                await OnServiceidSelect();
            }
        }

        //异步更新UI
        await InvokeAsync(StateHasChanged);
    }


    private async Task OnServiceidSelect(SelectedItem item)
    {
        if (IsAutoConnect || item.Value == "") return;
        BleInfo.Serviceid = Guid.Parse(item.Value);
        await OnServiceidSelect();
    }
    private async Task OnServiceidSelect()
    {
        Characteristics = null;
        Message = "";
        ReadResult = "";
        CharacteristicList = new List<SelectedItem>() { new SelectedItem() { Text = "请选择...", Value = "" } };
        Characteristics = await GetCharacteristicsAsync(BleInfo.Serviceid);
        if (Characteristics != null)
        {
            Characteristics.ForEach(a => CharacteristicList.Add(new SelectedItem() { Active = IsAutoConnect && a.Id == BleInfo.Characteristic, Text = a.Name ?? a.Id.ToString(), Value = a.Id.ToString() }));
            await Storage.SetValue("bleServiceid", BleInfo.Serviceid.ToString());
            if (BleInfo.Characteristic != Guid.Empty && IsAutoConnect)
            {
                await ReadDeviceName();
            }
        }
        await InvokeAsync(StateHasChanged);
    }

    private async Task OnCharacteristSelect(SelectedItem item)
    {
        if (IsAutoConnect) return;
        BleInfo.Characteristic = Guid.Parse(item.Value);
        await ReadDeviceName();
    }

    //读取数值
    private async Task ReadDeviceName()
    {
        Message = "";

        //读取数值
        ReadResult = await ReadDeviceName(BleInfo.Serviceid, BleInfo.Characteristic);
        await Storage.SetValue("bleCharacteristic", BleInfo.Characteristic.ToString());

        if (!string.IsNullOrEmpty(ReadResult)) await ToastService.Information("读取成功", ReadResult);
        //异步更新UI
        await InvokeAsync(StateHasChanged);
    }

    private async Task ReadDataAsync()
    {
        Message = "";
        //读取数值
        var res = await ReadDataAsync(BleInfo.Characteristic);
        if (!string.IsNullOrEmpty(ReadResult)) await ToastService.Information("读取成功", res.ToString());

        //异步更新UI
        await InvokeAsync(StateHasChanged);
    }

    private async Task SendDataAsync()
    {
        Message = "";
        //读取数值
        var res = await SendDataAsync(BleInfo.Characteristic, null);
        await ToastService.Information("成功发送", res.ToString());

        //异步更新UI
        await InvokeAsync(StateHasChanged);
    }

    ValueTask IAsyncDisposable.DisposeAsync()
    {
        OnMessage -= Tools_OnMessage;
        OnDataReceived -= Tools_OnDataReceived;
        OnStateConnect -= Tools_OnStateConnect;
        return new ValueTask();
    }

}

9. 添加 UI Pages/Index.razor

Index.razor

@page "/"

<h3>蓝牙</h3>

<div class="row g-3">
    <div class="btn-group" role="group">
        <Button Text="扫描外设" @attributes=IsScanningCss OnClick=ScanDevice />
        @if (Devices != null)
        {
            <Button Text="连接" OnClick="OnDeviceSelect" />
            <Button Text="断开" OnClick="OnDisConnectDevice" />
            @if (Characteristics != null)
            {
                <Button Text="写入" OnClick="ReadDeviceName" />
                <Button Text="读取" OnClick="ReadDeviceName" />
            }
        }
    </div>
</div>
@if (Devices != null)
{

    <div class="row g-3">
        <div class="col-12 col-sm-3">
            <Select TValue="Guid" Items="DeviceList" OnSelectedItemChanged="OnDeviceSelect" />
        </div>
        @if (Services != null)
        {
            <div class="col-12 col-sm-3">
                <Select TValue="Guid" Items="ServiceidList" OnSelectedItemChanged="OnServiceidSelect" />
            </div>
            @if (Characteristics != null)
            {
                <div class="col-12 col-sm-3">
                    <Select TValue="Guid" Items="CharacteristicList" OnSelectedItemChanged="OnCharacteristSelect" />
                </div>
                @if (ReadResult != null)
                {
                    <div class="col-12 col-sm-3">
                        <Display TValue="string" Value="@ReadResult" />
                    </div>
                }
            }
        }
    </div>

}

@if (BleInfo.Name != null)
{

    <div class="g-3">
        历史连接 <br />
        @BleInfo.Name <br />
        @BleInfo.DeviceID <br />
        @BleInfo.Serviceid <br />
        @BleInfo.Characteristic <br />
        @ReadResult <br />
    </div>

}
<Switch DisplayText="自动连接" OnText="自动连接" OffText="手动连接" Value="@IsAuto" OnValueChanged="@OnStateChanged" />

<pre style="max-height: 500px; overflow-y: scroll; white-space: pre-wrap; word-wrap: break-word;">@Message</pre>