.net 8 写接口发邮件

在.NET 8中，要通过接口发送电子邮件，你可以使用.NET框架自带的MailKit库或者第三方的SendGrid等服务提供的API。首先，你需要安装相应的NuGet包，例如`Microsoft.NET.Http.Client`用于HTTP请求，`MailKit`处理SMTP协议。

下面是一个简单的步骤概述：

1. 添加依赖项：

   dotnet add package MailKit
   dotnet add package System.Net.Http

2. 创建一个接口，定义发送邮件的功能：

public interface IEmailSender
{
    Task SendEmailAsync(string fromAddress, string toAddress, string subject, string body);
}

3. 实现这个接口：

public class SmtpEmailSender : IEmailSender
{
    private readonly IMailService _mailService;

    public SmtpEmailSender(string smtpServer, int smtpPort, string username, string password)
    {
        _mailService = new MailKit.Net.Smtp.SmtpClient(smtpServer, smtpPort);
        _mailService.Connect(smtpServer, smtpPort, SecureSocketOptions.Auto);
        _mailService.Authenticate(username, password);
    }

    public async Task SendEmailAsync(string fromAddress, string toAddress, string subject, string body)
    {
        var message = new MimeMessage();
        message.From.Add(new MailboxAddress(fromAddress));
        message.To.Add(toAddress);
        message.Subject = subject;
        message.Body = new TextPart("plain") { Text = body };

        await _mailService.SendAsync(message);
        await _mailService.DisconnectAsync(true);
    }
}

4. 使用接口发送邮件：

var emailConfig = new EmailConfiguration
{
    SmtpServer = "your-smtp-server",
    SmtpPort = 587,
    Username = "your-email",
    Password = "your-password"
};

using (var sender = new SmtpEmailSender(emailConfig.SmtpServer, emailConfig.SmtpPort, emailConfig.Username, emailConfig.Password))
{
    await sender.SendEmailAsync("sender@example.com", "recipient@example.com", "Subject", "Body text");
}