获取 Windows 通知中心弹窗通知内容（含工具汉化）

前言

技术原理概述

测试代码和程序下载连接

本文出处链接：https://blog.csdn.net/qq_59075481/article/details/136440280。

前言

从 Windows 8.1 开始，Windows 通知现在以 Toast 而非 Balloon 形式显示（ Bollon 通知其实现在是应用通知的一个子集），并记录在通知中心中。到目前为止，为了检索通知的内容，您必须抓取窗口的句柄并尝试读取它的文本内容，或者其他类似的东西。

特别是在 Toast 可用之后，这样做变得很困难，但从 Windows 10 Anniversary Edition (10.0.14393.0) 版本开始， MS 实现了“通知监听器” API（UserNotificationListener），允许您以与获取 Android 通知相同的方式获取 Windows 通知。

技术原理概述

参考 gpsnmeajp 的代码思路，

（原文翻译：https://blog.csdn.net/qq_59075481/article/details/136433878）

我们使用 UserNotificationListener 这个 WinRT API 来监视系统通知区域的弹窗。该 API 不仅可以拦截 Toast 通知（应用通知），而且可以拦截旧式的 Balloon 通知。

下面是异步获取消息的处理代码（await 异步关键字在 C++ 中没有，需要额外的自己构建处理模式，所以一般代码使用 C#）：

首先，我们只关心前三个字段 id、title 和 body。title 是通知的标题，body 是通知的内容。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Windows.Forms;
using Windows.UI.Notifications.Management;
using Windows.Foundation.Metadata;
using Windows.UI.Notifications;

namespace NotificationListenerThrower
{
    class NotificationMessage
    {
        public uint id { get; set; }
        public string title { get; set; }
        public string body { get; set; }

        public NotificationMessage(uint id, string title, string body) {
            this.id = id;
            this.title = title != null ? title : "";
            this.body = body != null ? body : "";
        }
    }
}

获取消息的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Windows.Forms;
using Windows.UI.Notifications.Management;
using Windows.Foundation.Metadata;
using Windows.UI.Notifications;


namespace NotificationListenerThrower
{
    class Notification
    {
        bool accessAllowed = false;
        UserNotificationListener userNotificationListener = null;

        public async Task<bool> Init()
        {
            if (!ApiInformation.IsTypePresent("Windows.UI.Notifications.Management.UserNotificationListener"))
            {
                accessAllowed = false;
                userNotificationListener = null;
                return false;
            }

            userNotificationListener = UserNotificationListener.Current;
            UserNotificationListenerAccessStatus accessStatus = await userNotificationListener.RequestAccessAsync();

            if (accessStatus != UserNotificationListenerAccessStatus.Allowed) {
                accessAllowed = false;
                userNotificationListener = null;
                return false;
            }
            accessAllowed = true;
            return true;
        }

        public async Task<List<NotificationMessage>> Get()
        {
            if (!accessAllowed) {
                return new List<NotificationMessage>();
            }

            List<NotificationMessage> list = new List<NotificationMessage>();

            IReadOnlyList<UserNotification> userNotifications = await userNotificationListener.GetNotificationsAsync(NotificationKinds.Toast);
            foreach (var n in userNotifications)
            {
                var notificationBinding = n.Notification.Visual.GetBinding(KnownNotificationBindings.ToastGeneric);
                if (notificationBinding != null)
                {
                    IReadOnlyList<AdaptiveNotificationText> textElements = notificationBinding.GetTextElements();
                    string titleText = textElements.FirstOrDefault()?.Text;
                    string bodyText = string.Join("\n", textElements.Skip(1).Select(t => t.Text));

                    list.Add(new NotificationMessage(n.Id, titleText, bodyText));
                }
            }
            return list;
        }
    }

}

gpsnmeajp 通过将功能写入 ListBox 和转发到 WebSocket 实现向远程客户端分发通知的信息。

NotificationListenerThrower 作为中间人获取 Windows 通知中心的消息内容，并通过 WebSocket 向客户端转发消息内容（模式-> 外模式）。

下面是该工具的 WebSocket 前/后端实现。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Windows.Forms;
using Windows.UI.Notifications.Management;
using Windows.Foundation.Metadata;
using Windows.UI.Notifications;


namespace NotificationListenerThrower
{
    class Websocket
    {
        HttpListener httpListener = null;
        Task httpListenerTask = null;

        List<WebSocket> WebSockets = new List<WebSocket>();

        bool localOnly = false;
        bool viewer = false;

        public void Open(string port, bool localOnly, bool viewer) {
            this.localOnly = localOnly;
            this.viewer = viewer;

            string host = localOnly ? "127.0.0.1" : "+";

            httpListener = new HttpListener();
            httpListener.Prefixes.Add("http://" + host + ":" + port + "/");
            httpListener.Start();

            //接続待受タスク
            httpListenerTask = new Task(async () => {
                try
                {
                    while (true)
                    {
                        HttpListenerContext context = await httpListener.GetContextAsync();
                        if (localOnly == true && context.Request.IsLocal == false)
                        {
                            context.Response.StatusCode = 400;
                            context.Response.Close(Encoding.UTF8.GetBytes("400 Bad request"), true);
                            continue;
                        }

                        if (!context.Request.IsWebSocketRequest)
                        {
                            if (viewer)
                            {
                                context.Response.StatusCode = 200;
                                context.Response.Close(Encoding.UTF8.GetBytes(html), true);
                            }
                            else {
                                context.Response.StatusCode = 404;
                                context.Response.Close(Encoding.UTF8.GetBytes("404 Not found"), true);
                            }
                            continue;
                        }

                        if (WebSockets.Count > 1024)
                        {
                            context.Response.StatusCode = 503;
                            context.Response.Close(Encoding.UTF8.GetBytes("503 Service Unavailable"), true);
                            continue;
                        }

                        HttpListenerWebSocketContext webSocketContext = await context.AcceptWebSocketAsync(null);
                        WebSocket webSocket = webSocketContext.WebSocket;

                        if (localOnly == true && webSocketContext.IsLocal == false)
                        {
                            webSocket.Abort();
                            continue;
                        }

                        WebSockets.Add(webSocket);
                    }
                }
                catch (HttpListenerException)
                {
                    //Do noting (Closed)
                }
            });
            httpListenerTask.Start();
        }

        public async Task Broadcast(string msg) {
            ArraySegment<byte> arraySegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes(msg));
            foreach (var ws in WebSockets)
            {
                try
                {
                    if (ws.State == WebSocketState.Open)
                    {
                        await ws.SendAsync(arraySegment, WebSocketMessageType.Text, true, CancellationToken.None);
                    }
                    else
                    {
                        ws.Abort();
                    }
                }
                catch (WebSocketException)
                {
                    //Do noting (Closed)
                }
            }
            WebSockets.RemoveAll(ws => ws.State != WebSocketState.Open);
        }

        public void Close() {
            foreach (var ws in WebSockets)
            {
                ws.Abort();
                ws.Dispose();
            }
            WebSockets.Clear();

            try
            {
                httpListener?.Stop();
            }
            catch (Exception) { 
                //Do noting
            }
            httpListenerTask?.Wait();
            httpListenerTask?.Dispose();
        }

        public int GetConnected() {
            return WebSockets.Count;
        }


        string html = @"<html>
<head>
<meta charset='UTF-8'/>
<meta name='viewport' content='width=device-width,initial-scale=1'>
</head>
<body>
<input id='ip' value='ws://127.0.0.1:8000'></input>
<button onclick='connect();'>开始连接</button>
<button onclick='disconnect();'>取消连接</button>
<div id='ping'></div>
<div id='log'></div>
<script>
let socket = null;
let lastupdate = new Date();

window.onload = function() {
	document.getElementById('ip').value = 'ws://'+location.host;
    connect();
};
function connect(){
	try{
	if(socket != null){
		socket.close();
	}
	socket = new WebSocket(document.getElementById('ip').value);
	socket.addEventListener('error', function (event) {
	    document.getElementById('log').innerText = '连接失败';	
	});
	socket.addEventListener('open', function (event) {
	    document.getElementById('log').innerText = '持续连接中...';	
	});
	socket.addEventListener('message', function (event) {
        let packet = JSON.parse(event.data);
		if('ping' in packet){
            lastupdate = new Date();
		    document.getElementById('ping').innerText = 'ping: '+lastupdate;
		}else{
		    document.getElementById('log').innerText = packet.id +':'+packet.title+':'+packet.body +'\n'+ document.getElementById('log').innerText;
		}
	});
	socket.addEventListener('onclose', function (event) {
	    document.getElementById('log').innerText = document.getElementById('log').innerText +'\n' +'CLOSED';
		socket.close();
		socket = null;
	});
	}catch(e){
	    document.getElementById('log').innerHTML = e;	
	}
}
function disconnect(){
	socket.close();
	socket = null;
    document.getElementById('log').innerText = '正在连接';	
}
function timeout(){
    if(new Date().getTime() - lastupdate.getTime() > 3000){
        if(socket != null){
            document.getElementById('ping').innerText = 'ping: 超时! 正在重新连接...';
            disconnect();
            connect();
        }else{
            document.getElementById('ping').innerText = 'ping: 超时!';
        }
    }
}
setInterval(timeout,1000);

</script>
</body>
</html>";
    }
}

应用程序及后端代码如下。其中在 WatchTimer_Tick 方法内修复了使用默认参数调用 JsonSerializer 在序列化文本时，编码错误的问题。这使得中文文本可以正常显示在应用程序中。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.IO;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Windows.Forms;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace NotificationListenerThrower
{
    public partial class Form1 : Form
    {
        class Setting {
            public string port { get; set; }
            public bool localonly { get; set; }
            public bool viewer{ get; set; }
        }

        Websocket websocket = new Websocket();
        Notification notification = new Notification();
        uint sent = 0;

        public Form1()
        {
            InitializeComponent();
        }

        private async void Form1_Load(object sender, EventArgs e)
        {
            if (!await notification.Init())
            {
                PresentTextBox.Text = "载入中";
                PresentTextBox.BackColor = Color.Red;
                return;
            }
            PresentTextBox.Text = "就绪";
            PresentTextBox.BackColor = Color.Green;

            open(load());
        }
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            websocket.Close();
        }

        List<NotificationMessage> lastNotificationMessage = new List<NotificationMessage>();
        private async void WatchTimer_Tick(object sender, EventArgs e)
        {
            List<NotificationMessage> notificationMessage = await notification.Get();

            DetectedListBox.Items.Clear();
            foreach (var n in notificationMessage)
            {
                // 使用 UnsafeRelaxedJsonEscaping 编码器，
                // 它会在 JSON 字符串中对非 ASCII 字符进行逃逸处理，
                // 以确保正确的序列化。
                var options = new JsonSerializerOptions
                {
                    Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping
                };

                string msg = JsonSerializer.Serialize(n, options);

                // 支持中文编码
                DetectedListBox.Items.Add(msg);

                if (lastNotificationMessage.Where(l => l.id == n.id).Count() == 0) {
                    // 新建
                    await websocket.Broadcast(msg);
                    sent = unchecked(sent + 1);
                }
            }
            lastNotificationMessage = notificationMessage;

            SendTextBox.Text = sent.ToString();
       }
        private async void PingTimer_Tick(object sender, EventArgs e)
        {
            ConnectedTextBox.Text = websocket.GetConnected().ToString();
            await websocket.Broadcast("{\"ping\":true}");
        }


        private void ApplyButton_Click(object sender, EventArgs e)
        {
            open(save());
        }

        private Setting load()
        {
            Setting setting;
            if (File.Exists("setting.json"))
            {
                string json = File.ReadAllText("setting.json");
                try
                {
                    setting = JsonSerializer.Deserialize<Setting>(json);
                    PortTextBox.Text = setting.port;
                    LocalOnlyCheckBox.Checked = setting.localonly;
                    ViewerCheckBox.Checked = setting.viewer;
                    return setting;
                }
                catch (JsonException)
                {
                    //Do noting (json error)
                }
            }
            setting = new Setting
            {
                port = PortTextBox.Text,
                localonly = LocalOnlyCheckBox.Checked,
                viewer = ViewerCheckBox.Checked
            };
            return setting;
        }
        private Setting save()
        {
            Setting setting = new Setting
            {
                port = PortTextBox.Text,
                localonly = LocalOnlyCheckBox.Checked,
                viewer = ViewerCheckBox.Checked
            };

            string json = JsonSerializer.Serialize(setting);
            File.WriteAllText("setting.json", json);
            return setting;
        }

        private void open(Setting setting)
        {
            AccessStatusTextBox.Text = "CLOSED";
            AccessStatusTextBox.BackColor = Color.Red;

            websocket.Close();

            try
            {
                websocket.Open(setting.port, setting.localonly, setting.viewer);
            }
            catch (HttpListenerException e) {
                MessageBox.Show(e.Message);
                return;
            }
            AccessStatusTextBox.Text = "OPEN";
            AccessStatusTextBox.BackColor = Color.Green;
        }
    }
}

这款软件的汉化界面如下图：