c# - 如何在配置服务中将ILogger <T>依赖项注入(inject)服务-.NET Core 2.0

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);
        }
    }

}

我想使用实现工厂来创建此服务，因为我将从配置中读取smtp设置，并像Startup.cs中所示的那样提供smtp客户端：

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？

最佳答案

这行不行吗？

services.AddTransient<IMailService>(provider =>

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