如何从c＃Core中的DI获取可用的IOptions列表？ [英] How to get the list of IOptions available from DI in c# Core?
问题描述
关注此帖子： https：//blog.bredvid .no / validating-configuration-in-asp-net-core-e9825bd15f10
我现在可以在服务需要时对设置进行验证。我想做的是直接在server.cs中启动服务器时进行验证。
I m now available to validate the Settings when a service need it. What I would like to do is to validate directly when the server starts in program.cs.
我不确定该怎么做？有没有一种方法可以获取注入到DI中的服务列表，然后验证是否可以从IOption分配类型并进行注册？
I m not sure how to do it? Is there a way to get the list of services injected in DI then verify if the type is assignable from IOption and register it?
这是我如何向DI添加设置：
Here is how I add to DI the Settings:
//App settings
services.ConfigureAndValidate<AuthenticationSettings>(Configuration);
services.ConfigureAndValidate<SmtpSettings>(Configuration);
扩展代码：
public static class IServiceCollectionExtensions
{
public static IServiceCollection ConfigureAndValidate<T>(
this IServiceCollection serviceCollection,
IConfiguration config,
string section = null
) where T : class
{
var configType = typeof(T).Name;
if (string.IsNullOrEmpty(section)) {
section = configType;
}
return serviceCollection
.Configure<T>(config.GetSection(section))
.PostConfigure<T>(settings =>
{
var configErrors = settings.ValidationErrors().ToArray();
if (configErrors.Any())
{
var aggrErrors = string.Join(",", configErrors);
var count = configErrors.Length;
throw new ApplicationException($"Found {count} configuration error(s) in {configType}: {aggrErrors}");
}
});
}
private static IEnumerable<string> ValidationErrors(this object obj)
{
var context = new ValidationContext(obj, serviceProvider: null, items: null);
var results = new List<ValidationResult>();
Validator.TryValidateObject(obj, context, results, true);
foreach (var validationResult in results)
{
yield return validationResult.ErrorMessage;
}
}
}
这是我当前的启动器：
Here is my current launcher:
public class Program
{
public static async Task Main(string[] args)
{
var webHost = new WebHostBuilder()
.UseKestrel()
.UseContentRoot(Directory.GetCurrentDirectory())
.ConfigureAppConfiguration((hostingContext, config) =>
{
config.AddEnvironmentVariables();
var env = hostingContext.HostingEnvironment;
config.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true);
})
.ConfigureLogging((hostingContext, logging) =>
{
logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
logging.AddConsole();
logging.AddDebug();
})
.UseStartup<Startup>()
.Build();
using (var scope = webHost.Services.CreateScope())
{
var services = scope.ServiceProvider;
/// <---- BEGIN / AN IDEA OF WHAT I WOULD LIKE TO DO ---->
/// <---- THIS CODE IS NOT WORKING ---->
var allServices = services.GetAllServices();
if (allServices != null)
{
foreach (var service in allServices )
{
if (service.ServiceType.IsAssignableFrom(IOptions))
{
services.GetRequiredService<service.ServiceType>()
}
}
}
/// <---- END ---->
}
await webHost.RunAsync();
}
}
如果您有任何建议，请告诉我。
Let me know if you have any suggestions in comment.
感谢您的帮助。
编辑1：
感谢史蒂文（Steven）的帮助，并为您提供了答案，它帮助我继续找到了答案，但是事情仍然不见了。
EDIT 1: Thanks Steven for your help, with your answer, it helped me to continue to find an answer, but things are still missing.
现在，我所有的设置都继承了来自ISettings，例如：
now, all my settings inherit from ISettings, like:
public class AuthenticationSettings : ISettings
{
[Required]
public string Issuer { get; set; }
[Required]
public string Audience { get; set; }
[Required]
public string SecretKey { get; set; }
[Required]
public int ExpirationDurationInDays { get; set; }
}
我更新Program.cs就像：
I update Program.cs like:
using Autofac;
using Autofac.Core;
var options = services.GetService<ILifetimeScope>()
.ComponentRegistry
.Registrations.SelectMany(e => e.Services)
.Select(s => s as TypedService)
.Where(s => s.ServiceType.IsGenericType && s.ServiceType.GetGenericTypeDefinition() == typeof(IConfigureOptions<>))
.Select(s => s.ServiceType.GetGenericArguments()[0])
.Where(s => typeof(ISettings).IsAssignableFrom(s))
.ToList();
所以现在我需要实例化选项中的每个选项并获取值。我还在努力。让我知道您是否有任何建议或解决方案：）
so now I need to instantiate each option in options and get the Value. I m still working on it. let me know if you have any suggestion or the solution :)
推荐答案
以下是史蒂文的建议，这是我的解决方案：
我的设置验证器服务
Following suggestions from Steven, here is my solution: My settings validator service
public SettingsValidator(
IServiceProvider services,
ILifetimeScope scope
)
{
var types = scope.ComponentRegistry.Registrations
.SelectMany(e => e.Services)
.Select(s => s as TypedService)
.Where(s => s.ServiceType.IsAssignableToGenericType(typeof(IConfigureOptions<>)))
.Select(s => s.ServiceType.GetGenericArguments()[0])
.Where(s => typeof(ISettings).IsAssignableFrom(s))
.ToList();
foreach (var t in types)
{
var option = services.GetService(typeof(IOptions<>).MakeGenericType(new Type[] { t }));
option.GetPropertyValue("Value");
}
}
在启动时：
builder.RegisterType<SettingsValidator>();
设置示例
public class AzureStorageSettings : ISettings
{
[Required]
public string ConnectionString { get; set; }
[Required]
public string Container { get; set; }
[Required]
public string Path { get; set; }
}
扩展名
public static class TypeExtensions
{
public static bool IsAssignableToGenericType(this Type givenType, Type genericType)
{
foreach (var it in givenType.GetInterfaces())
{
if (it.IsGenericType && it.GetGenericTypeDefinition() == genericType)
return true;
}
if (givenType.IsGenericType && givenType.GetGenericTypeDefinition() == genericType)
return true;
Type baseType = givenType.BaseType;
if (baseType == null) return false;
return IsAssignableToGenericType(baseType, genericType);
}
}
在program.cs
in program.cs
using (var scope = webHost.Services.CreateScope())
{
var services = scope.ServiceProvider;
var logger = services.GetRequiredService<ILogger<Program>>();
try
{
logger.LogInformation("Starting settings validation.");
services.GetRequiredService<SettingsValidator>();
logger.LogInformation("The settings have been validated.");
}
catch (Exception ex)
{
logger.LogError(ex, "An error occurred while validating the settings.");
}
}
让我知道它是否也对您有用:)
Let me know if it works for you too :)
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