ASP.NET Core 3.1将来自appsettings.json的对象数组注入注入的服务

本文介绍了ASP.NET Core 3.1将来自appsettings.json的对象数组注入注入的服务的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试将appsettings.json中的几个电子邮件帐户注入电子邮件服务。

编辑：我的EmailRepository.cs也需要注入DbContext。我使用了@Nkosi的答案，它在不需要DbContext的情况下起作用。我计划在生产中使用DbContextPool，那么如何在我的ConfigureServices方法中提取其中一个？

appsettings.json：

"SanSenders": [ { "Host": "mail.theFourSeasons", "FromName": "The Four Seasons", "IsNoReply": true, "IsSssl": true, "Password": "tooGoodToBeTrue", "Port": 465, "Username": "noreply@theFourSeasons" }, { "Host": "mail.theFourSeasons", "FromName": "Franki", "IsNoReply": false, "IsSssl": true, "Password": "cantTakeMyEyesOffYou", "Port": 465, "Username": "franki@theFourSeasons" } ]

SanSender.cs：

public class SanSender { public string FromName { get; set; } public string Host { get; set; } public bool IsNoReply { get; set; } public bool IsSsl { get; set; } public string Password { get; set; } public int Port { get; set; } public string Username { get; set; } public async Task<bool> SendEmailAsync( string toAddress, string subject, string htmlMessage) { throw new NotImplementedException(); } }

EmailRepository.cs：

public class EmailRepository { public IEnumerable<SanSender> SanSenders { get; set; } //Edit: I need a DbContext injected as well. public EmailRepository(ApplicationDbContext applicationDbContext, IEnumerable<SanSender> sanSenders) { SanSenders = sanSenders; } }

Startup.cs：

public void ConfigureServices(IServiceCollection services) { services.Configure<List<SanSender>>((settings) => { Configuration.GetSection("SanSenders").Bind(settings); }); services.AddScoped<EmailRepository>(); services.AddControllersWithViews(); }

控制器：

public class HomeController : Controller { public HomeController( IOptions<List<SanSender>> optionsSanSenders, EmailRepository emailService) { } public IActionResult Index() { return View(); } }

我在控制器中添加了IOptions<List<SanSender>> optionsSanSenders，我可以在那里访问它们，但EmailService.cs在类库中，我不希望向它添加不必要的依赖项。

EmailService确实有IEnumerable<SanSender> SanSenders，但其长度/计数为零。

我做错了什么？

推荐答案

更改方法。

public class SanSenderOptions { public List<SanSender> SanSenders { get; set; } }

从配置中提取设置，然后在需要的地方注册它们

public void ConfigureServices(IServiceCollection services) { SanSender[] senders = Configuration.GetSection("SanSenders").Get<SanSender[]>(); services.Configure<SanSenderOptions>(options => { options.SanSenders = senders.ToList(); }); services.AddScoped<EmailRepository>(sp => new EmailRepository(sp.GetRequiredService<ApplicationDbContext>(), senders)); services.AddControllersWithViews(); }

存储库将解析注入的发件人。

应重构控制器以获得配置的选项。

public class HomeController : Controller { public HomeController(IOptions<SanSenderOptions>> optionsSanSenders, EmailRepository emailService) { var senders = options.Value.SanSenders; //<-- } public IActionResult Index() { return View(); } }

引用Configuration in ASP.NET Core

引用Options pattern in ASP.NET Core