using System;
public class EmailServiceOptions
{
    public string SmtpServer { get; set; }
    public int SmtpPort { get; set; }
    public string SenderEmail { get; set; }
    public string SenderPassword { get; set; }
}

using System;
using System.Net;
using System.Net.Mail;
public class EmailService
{
    private readonly EmailServiceOptions _options;
    public EmailService(EmailServiceOptions options)
    {
        _options = options;
    }
    public void SendEmail(string to, string subject, string message)
    {
        using (var client = new SmtpClient(_options.SmtpServer, _options.SmtpPort))
        {
            client.Credentials = new NetworkCredential(_options.SenderEmail, _options.SenderPassword);
            client.EnableSsl = true;
            var mail = new MailMessage(_options.SenderEmail, to, subject, message);
            client.Send(mail);
        }
        Console.WriteLine($"已發(fā)送郵件給: {to}");
    }
}

using System;
using Microsoft.Extensions.DependencyInjection;
class Program
{
    static void Main(string[] args)
    {
        // 創(chuàng)建依賴注入容器
        var serviceProvider = new ServiceCollection()
            .AddScoped<EmailService>() // 注冊(cè) EmailService 服務(wù)
            .Configure<EmailServiceOptions>(options =>
            {
                options.SmtpServer = "smtp.example.com";
                options.SmtpPort = 587;
                options.SenderEmail = "sender@example.com";
                options.SenderPassword = "mypassword";
            })
            .BuildServiceProvider();
        // 獲取EmailService服務(wù)
        var emailService = serviceProvider.GetRequiredService<EmailService>();
        // 發(fā)送郵件
        emailService.SendEmail("recipient@example.com", "Test Email", "This is a test email message.");
        Console.ReadLine();
    }
}