如何在 C# .Net 中设置方法依赖关系注入

问：

您好，我正在尝试实现一个将日志输入到文件中的记录器。文件的路径存储在我的appSettings.json中。在模型类中，我参考了我的appSettings.json。下面是 LogWriter.cs

    public class LogWriter
    {
        public void WriteLog(string message, IOptions<AppSettings> appSettings)
        {
            AppSettings _appSettings = appSettings.Value;
            using (StreamWriter writer = new StreamWriter(_appSettings.LogFilePath))
            {
                writer.Write("[" + DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss") +"] " + message);
            }
        }
    }

我想通过 WriteLog 方法注入 appSettings 依赖项，以便我可以在不创建 LogWriter 类的实例的情况下调用该方法。为了创建依赖项，我向您展示了我的程序 .cs

var builder = WebApplication.CreateBuilder(args);

builder.Configuration
    .SetBasePath(Directory.GetCurrentDirectory())
    .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);

var appSettings = new AppSettings();
builder.Configuration.GetSection("AppSettings").Bind(appSettings);

//Add services to the container.
builder.Services.Configure<AppSettings>(builder.Configuration.GetSection("AppSettings"));
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

builder.Services.AddScoped<IMessageService, MessageService>();
builder.Services.AddScoped<LogWriter>();// DI for LogWriter

builder.Services.AddDbContext<MailContext>(
    o => o.UseNpgsql(appSettings.ConnectionStrings.MailDb)
    );

var app = builder.Build();

app.UseSwagger();
app.UseSwaggerUI();

app.UseAuthorization();
app.MapControllers();

app.Run();

当我用 调用方法时，我收到一个错误，即缺少一个参数。例如，在我的控制器中。LogWriter.WriteLog("Text for testing")

    [Route("[controller]")]
    [ApiController]
    public class MessageController : ControllerBase
    {
        private readonly IMessageService _mailService;

        public MessageController(IMessageService mailServiceCustom )
        {
            _mailService = mailServiceCustom;
            LogWriter.WriteLog("Construktor wird ausgeführt");

        }
...