我有一个SvcPool类,它注册为单例服务,
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<SvcPool, SvcPool>();
}
SvcPool将在构造函数内部基于config初始化几个Svc,但是Svc类构造函数需要一个ILogger。
如何让ILogger成为Svc的构造函数?
Svc.cs
public Svc(int id, string host, ILogger<Svc> logger)
{
...
}
SvcPool.cs
public SvcPool(IOptions<AppConfig> config, ILogger<SvcPool> logger)
{
foreach (var svcConfig in config.SvcList)
{
Svc svc = new Svc(svcConfig.ID, svcConfig.Host, ???);
}
}
我认为你有三种选择。我按照我认为最好的顺序命令它们 - >最差,但使用适合你的那个。
1 - 为Svc创建一个工厂:
services.AddSingleton<Svc.Factory>(svcProvider => (id, host) => new Svc(id, host, svcProvider.GetRequiredService<ILogger<Svc>>()));
public class Svc
{
public delegate Svc Factory(int id, string host);
public Svc(int id, string host, ILogger<Svc> logger)
{
}
}
public SvcPool(IOptions<AppConfig> config, ILogger<SvcPool> logger, Svc.Factory serviceFactory)
{
foreach (var svcConfig in config.SvcList)
{
Svc svc = serviceFactory(svcConfig.ID, svcConfig.Host);
}
}
2 - 注册一个工厂,你可以注入SvcPool
作为Func<ILogger<Svc>>
:
services.AddSingleton<Func<ILogger<Svc>>(svcProvider => () => svcProvider.GetRequiredService<ILogger<Svc>>());
public SvcPool(IOptions<AppConfig> config, ILogger<SvcPool> logger, Func<ILogger<Svc>> loggerFactory)
{
foreach (var svcConfig in config.SvcList)
{
Svc svc = new Svc(svcConfig.ID, svcConfig.Host, loggerFactory());
}
}
3 - 将IServiceProvider
注入SvcPool
,并使用服务定位器反模式来解析ILogger<svc>
的新实例
在实例化ILoggerFactory
时,您可以使用ILogger
并创建Svc
实例。
public SvcPool(IOptions<AppConfig> config, ILogger<SvcPool> logger, ILoggerFactory loggerFactory)
{
foreach (var svcConfig in config.Value.SvcList)
{
Svc svc = new Svc(svcConfig.ID, svcConfig.Host, loggerFactory.CreateLogger<Svc>());
}
}