ASP.NET Core 使用SignalR推送服务器日志的过程记录

public class KingkingLogger : ILogger
{
    private readonly string cateName;
    public KingkingLogger(string cate)
    {
        cateName = cate;
    }
    public IDisposable? BeginScope<TState>(TState state) where TState : notnull
    {
        return default;
    }
    public bool IsEnabled(LogLevel logLevel)
    {
        return logLevel != LogLevel.None;
    }
    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
    {
        if(IsEnabled(logLevel) == false)
        {
            return;
        }
        // 获取格式化后的文本
        string fstr = formatter(state, exception);
        // 显示消息类型
        string head = logLevel switch
        {
            LogLevel.Information => "消息",
            LogLevel.Warning => "警告",
            LogLevel.Error => "错误",
            _ => "未知"
        };
        // 加个日期
        string currdate = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
        // 连接字符串
        fstr = $"[{head}:{cateName}][{currdate}]{fstr}";
        // 触发事件
        TransferLog?.Invoke(fstr);
    }
    // 静态属性
    public static Action<string>? TransferLog {  get; set; }
}

public class KingkingLoggerProvider : ILoggerProvider
{
    public ILogger CreateLogger(string categoryName)
    {
        return new KingkingLogger(categoryName);
    }
    public void Dispose()
    {
        return;
    }
}

public static class CustLoggerExtensions
{
    public static ILoggingBuilder AddKingkingLogger(this ILoggingBuilder builder)
    {
        builder.Services.AddSingleton<ILoggerProvider, KingkingLoggerProvider>();
        return builder;
    }
}

var builder = WebApplication.CreateBuilder(args);
// 配置日志
builder.Services.AddLogging(o =>
{
    // 清空所有日志提供者
    o.ClearProviders();
    // 添加控制台日志输出
    o.AddConsole();
    // 添加咱们自己写的日志记录器
    o.AddKingkingLogger();
});

public class MyHub : Hub
{
    public MyHub() {
        // 这里关联的就是日志记录类中的静态委托
        KingkingLogger.TransferLog = KingkingLogger_TransferLog;
    }
    private void KingkingLogger_TransferLog(string obj)
    {
        // 向所有客户端发日志
        Clients.All.SendAsync("onLogged", obj);
    }
    protected override void Dispose(bool disposing)
    {
        if(disposing)
        {
            // 实例释放时移除关联
            KingkingLogger.TransferLog = null;
        }
        base.Dispose(disposing);
    }
}

var builder = WebApplication.CreateBuilder(args);
……
builder.Services.AddSignalR();
var app = builder.Build();

var builder = WebApplication.CreateBuilder(args);
……
var app = builder.Build();
……
// 记得这个
app.MapHub<MyHub>("/hub");
app.Run();

var builder = WebApplication.CreateBuilder(args);
……
// 把Hub注册为单实例
builder.Services.AddSingleton<MyHub>();
builder.Services.AddSignalR();
var app = builder.Build();

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net8.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <UseWindowsForms>true</UseWindowsForms>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.0" />
  </ItemGroup>
</Project>

using Microsoft.AspNetCore.SignalR.Client;
namespace TestClient;
public partial class Form1 : Form
{
    // 连接对象
    HubConnection hubConn;
    public Form1()
    {
        InitializeComponent();
        // 初始化连接
        var connBuilder = new HubConnectionBuilder()
            .WithUrl("http://localhost:6225/hub")
            .WithAutomaticReconnect();
        hubConn = connBuilder.Build();
        // 关联方法
        hubConn.On<string>("onLogged", OnLogRecv);
    }
    private void OnLogRecv(string msg)
    {
        // 服务器回调，显示收到的日志
        textBox1.Invoke(() =>
        {
            textBox1.AppendText(msg + Environment.NewLine);
        });
    }
    private async void btnConn_Click(object sender, EventArgs e)
    {
        try
        {
            await hubConn.StartAsync();
            lbMessage.Text = "已建立连接";
        }
        catch(Exception ex) {
            lbMessage.Text = ex.Message;
        }
    }
    private async void btnDisconn_Click(object sender, EventArgs e)
    {
        if(hubConn.State == HubConnectionState.Connected)
        {
            await hubConn.StopAsync();
            lbMessage.Text = "已断开连接";
        }
    }
}

/*---------------- 服务器端 ------------------*/
private void KingkingLogger_TransferLog(string obj)
{
    // 向所有客户端发日志
    Clients.All.SendAsync("onLogged", obj);
}

/*--------------------- 客户端 -------------------*/
hubConn.On<string>("onLogged", OnLogRecv);

app.MapGet("/", (ILoggerFactory logFact) =>
{
    ILogger logger = logFact.CreateLogger("MINI Main");
    logger.LogInformation("欢迎来到圆环世界");
    return "Hello Guy";
});
app.MapGet("/start", (ILoggerFactory logFact) =>
{
    ILogger logger = logFact.CreateLogger("MINI Go Go Go");
    logger.LogWarning("游戏开始了，你必须先和QB签订契约");
    return "圆神启动";
});
app.MapGet("/shot", (ILoggerFactory loggerFact) =>
{
    ILogger logger = loggerFact.CreateLogger("MINI Wind");
    logger.LogInformation("干得好，三发入魂");
    return "第一局完胜";
});