MAUI + Masa Blazor 开发带自动更新功能的安卓App

自动更新主要下面4个步骤

获取最新版本号
提示用户发现更新，等待用户确认更新
下载最新的apk包
安装apk包.

下面从创建MAUI项目开始

1、创建Maui Blazor Server应用

2、安装Masa.Blazor，并添加引用

dotnet add package Masa.Blazor

在 wwwroot/index.html 中引入资源文件

npm/@mdi/font@5.x/css/materialdesignicons.min.css"rel="stylesheet">

npm/materialicons/materialicons.css" rel="stylesheet">

npm/fontawesome/v5.0.13/css/all.css" rel="stylesheet">
<link rel="stylesheet" href="https://cdn.masastack.com/

stack/fonts/roboto/font-roboto.css">

<script src="_content/BlazorComponent/js/blazor-component.js"></script>

在 _Imports.razor 添加，对Masa Blazor 的全局引用

@using Masa.Blazor
@using BlazorComponent

在MauiProgram.cs中注入服务

builder.Services.AddMasaBlazor();

修改Shared / MainLayout.razor文件，设置MApp为根元素

@inherits LayoutComponentBase

<div class="page">
<div class="sidebar">
    <NavMenu />
</div>
<main>
    <div class="top-row px-4">
<a href="https://docs.microsoft.com/aspnet/" target="_blank">About</a>
    </div>
    <article class="content px-4">
     <MApp>@Body</MApp>
</article>
</main>

</div>

项目属性中修改-已共享MAUI-中的应用程序ID及版本

3、开始编写代码

创建Service目录，添加IUpgradeService.cs接口

namespace MauiMasaBlazorDemo.Service{
public interface IUpgradeService
{
/// <summary>
/// 检查更新
/// </summary>
/// <param name="url">
/// 检查URL
/// </param>
/// <returns></returns>
Task<Dictionary<string, string>> CheckUpdatesAsync(string url);

/// <summary>
/// 下载安装文件
/// </summary>
/// <param name="url">
/// 下载URL
/// </param>
/// <param name="action">
/// 进度条处理方法
/// </param>
/// <returns></returns>
Task DownloadFileAsync(string url, Action<long, long> action);

/// <summary>
/// 安装APK的方法
/// </summary>
void InstallNewVersion();
}}

这里需要使用到 FileProvider，在Android 7之后出于安全考虑不再支持content://URL 或file:///URL这种文件访问方式，可参考FileProvider | Android Developers ，我们先添加一下对应配置

在Platforms/Android/Resources下面新建xml文件夹，并添加provider_paths.xml文件

<?xml version="1.0" encoding="utf-8"?>

</resources>

修改Platforms / Android下面的AndroidManifest.xml文件，在application下添加provider，再添加一个安卓安装的权限REQUEST_INSTALL_PACKAGES

<?xml version="1.0" encoding="utf-8"?>

</manifest>

在Platforms / Android下添加UpgradeService.cs

获取版本号可以通过MAUI提供的 VersionTracking，该类还有很多版本相关的功能，可参考

Version tracking - .NET MAUI | Microsoft Docs

Intent 是一种运行时绑定（run-time binding）机制，Android的三个基本组件 Activity，Service和Broadcast Receiver 都是通过Intent机制激活的，有兴趣可参考
Intent | Android Developers

using Android.Content;

using Android.OS;

using MauiMasaBlazorDemo.Service;

namespace MauiMasaBlazorDemo

{
public class UpgradeService : IUpgradeService
{
readonly HttpClient _client;
public UpgradeService()
{
_client = new HttpClient();
}
public async Task<Dictionary<string, string>> CheckUpdatesAsync(string url)
{
var result = new Dictionary<string, string>();
// 获取当前版本号
var currentVersion = VersionTracking.CurrentVersion;
var latestVersion = await _client.GetStringAsync(url);
result.Add("CurrentVersion", currentVersion);
result.Add("LatestVersion", latestVersion);
return result;
}

public void InstallNewVersion()
{
var file = $"{FileSystem.AppDataDirectory}/{"com.masa.mauidemo.apk"}";

var apkFile = new Java.IO.File(file);

var intent = new Intent(Intent.ActionView);
// 判断Android版本
if (Build.VERSION.SdkInt >= BuildVersionCodes.N)
{
//给临时读取权限
intent.SetFlags(ActivityFlags.GrantReadUriPermission);
var uri = FileProvider.GetUriForFile

(Android.App.Application.Context, "com.masa.mauidemo.fileprovider", apkFile);
// 设置显式 MIME 数据类型
intent.SetDataAndType(uri, "application/vnd.android.package-archive");
}
else
{
intent.SetDataAndType(Android.Net.Uri.FromFile(new Java.IO.File(file)), "application/vnd.android.package-archive");
}
//指定以新任务的方式启动Activity
intent.AddFlags(ActivityFlags.NewTask);

//激活一个新的Activity
Android.App.Application.Context.StartActivity(intent);
}

public async Task DownloadFileAsync(string url, Action<long, long> action)
{
var req = new HttpRequestMessage(new HttpMethod("GET"), url);
var response = _client.SendAsync(req, HttpCompletionOption.ResponseHeadersRead).Result;
var allLength = response.Content.Headers.ContentLength;
var stream = await response.Content.ReadAsStreamAsync();
var file = $"{FileSystem.AppDataDirectory}/{"com.masa.mauidemo.apk"}";
await using var fileStream = new FileStream(file, FileMode.Create);
await using (stream)
{
var buffer = new byte[10240];
var readLength = 0;
int length;
while ((length = await stream.ReadAsync(buffer, 0, buffer.Length)) != 0)
{
readLength += length;
action(readLength, allLength!.Value);
// 写入到文件
fileStream.Write(buffer, 0, length);
}
}
}
}

其中com.masa.mauidemo.apk 为安装文件apk的文件名称。

在MauiProgram.cs中添加注入，这里使用条件编译，在平台为Android时使用

#ifANDROID
builder.Services.AddSingleton<IUpgradeService, UpgradeService>();

#endif

在Pages中新增Index.razor.cs

using BlazorComponent;

using Masa.Blazor;

using MauiMasaBlazorDemo.Service;

using Microsoft.AspNetCore.Components;

namespace MauiMasaBlazorDemo.Pages

{
public partial class Index
{
[Inject]
public IPopupService PopupService { get; set; }

[Inject]
private IUpgradeService UpgradeService { get; set; }
private int Ps { get; set; }

private long TotalBytesToReceive { get; set; }

private long BytesReceived { get; set; }

private long _unReadMsgCnt = 0;

private bool _updateDialog;
/// <summary>
/// 获取最新版本
/// </summary>
/// <returns></returns>
public async Task GetVersionNew()
{
var result = await UpgradeService.CheckUpdatesAsync

($"https://你的域名/update.txt?t={DateTime.Now.ToUniversalTime().Ticks}");
if (result["CurrentVersion"] != result["LatestVersion"])
{
var confirm = await PopupService.ConfirmAsync($"检测到新版本，是否升级", "版本号为：" + result["LatestVersion"]);
if (confirm)
{
_updateDialog = true;
await UpgradeService.DownloadFileAsync("https://你的域名/com.masa.mauidemo.apk", DownloadProgressChanged);
UpgradeService.InstallNewVersion();
}
}
else
{
await PopupService.AlertAsync($"当前版本已经是最新版,版本号为：" + result["LatestVersion"], AlertTypes.Success);
}
}

private void DownloadProgressChanged(long readLength, long allLength)
{
InvokeAsync(() =>
{
var c = (int)(readLength * 100 / allLength);
if (c > 0 && c % 5 == 0) //刷新进度为每5%更新一次，过快的刷新会导致页面显示数值与实际不一致
{
Ps = c; //下载完成百分比
BytesReceived = readLength / 1024; //当前已经下载的Kb
TotalBytesToReceive = allLength / 1024; //文件总大小Kb
StateHasChanged();
}
});
}
}

修改Index.razor 添加按钮、确认对话框、进度条组件。Masa blazor是国内不多可以完美支持MAUI的blazor组件

@page "/"

</MButton>

<div class="text-center">
<MDialog @bind-Value="_updateDialog"
Width="500">
<ChildContent>
<MCard>
<MCardTitle Class="text-h5 grey lighten-2">
正在更新请稍后...

</MCardTitle>
<MCardText>
@BytesReceived KB/@TotalBytesToReceive KB <MProgressLinear Value="@Ps" Striped Height="15" Color="light-blue">
<strong>@Ps %</strong>
</MProgressLinear>
</MCardText>
</MCard>
</ChildContent>
</MDialog>

</div>