如何注射ILogger 依赖于ConfigureServices中的服务 - .net core 2.0

Question

我有以下MailService：

public class MailService : IMailService
{
    private readonly ILogger<MailService> _logger;
    private readonly SmtpClient _client;

    public MailService(ILogger<MailService> logger, SmtpClient client)
    {
        _logger = logger;
        _client = client;
    }

    public async Task Send(string to, string subject, string body)
    {
        var message = new MailMessage
        {
            Subject = subject,
            Body = body,
            IsBodyHtml = true,
            From = new MailAddress("[email protected]")
        };

        message.To.Add(to);

        using (_client)
        {
            _logger.LogTrace($"Sending email from {message.From.Address} to {to}. Subject: {subject}");
            await _client.SendMailAsync(message);
        }
    }

}

我想使用实现工厂创建此服务，因为我将从配置中读取smtp设置并提供smtp客户端，如Startup.cs中的以下内容：

services.AddTransient<IMailService>(provider =>
{
    var mailService = new MailService(***LOGGER INSTANCE HERE***, new SmtpClient("127.0.0.1", 25));
    return mailService;
});

有没有办法获取记录器实例并将其提供给邮件服务？

Answer 1

这不行吗？

services.AddTransient<IMailService>(provider =>

        {
            return new MailService(provider.GetRequiredService<ILogger<MailService>>(), new SmtpClient());
        });

Answer 2

我想使用实现工厂创建此服务，因为我将从配置中读取smtp设置并提供smtp客户端

你不应该在实现工厂中添加IMailService，最好在实现工厂中添加SmtpClient

services.AddTransient<IMailService, MailService>();
services.AddTransient(_ => new SmtpClient("127.0.0.1", 25));