asp.net-core – 如何在.Net Core中将App.config更改为json配置

例如,默认情况下,使用类似于以下内容的东西在Startup类中构建配置：

public Startup(IHostingEnvironment env)
{
    var builder = new ConfigurationBuilder()
        .SetBasePath(env.ContentRootPath)
        .AddJsonFile("appsettings.json",optional: true,reloadOnChange: true)
        .AddJsonFile($"appsettings.{env.EnvironmentName}.json",optional: true)
        .AddEnvironmentVariables();
    Configuration = builder.Build();
}

这将从appsettings.json文件加载配置,并将密钥附加到配置根目录.如果您有以下appsettings文件：

{
  "Logging": {
    "IncludeScopes": false,"LogLevel": {
    "Default": "Debug","System": "Information","Microsoft": "Information"
    }
  },"ThreadSettings" : {
     "MaxThreads" : 4
  }
}

然后,您可以创建类似于以下内容的强类型ThreadSettings类：

public class ThreadSettings
{
    public int MaxThreads {get; set;}
}

最后,您可以通过向ConfigureServices方法添加Configure方法将此强类型设置类绑定到您的配置.

using Microsoft.Extensions.Configuration;
public void ConfigureServices(IServiceCollection services)
{
    services.Configure<ThreadSettings>(Configuration.GetSection("ThreadSettings"));
}

然后,您可以通过将其注入构造函数来从任何其他位置注入和访问您的设置类.例如：

public class MyFatController
{
    private readonly int _maxThreads;
    public MyFatController(ThreadSettings settings)
    {
        maxThreads = settings.MaxThreads;
    }
}

最后,如果您确实需要访问底层配置,您还可以在ConfigureServices中注入它以使其在您的类中可用.

public void ConfigureServices(IServiceCollection services)
{
    services.AddSingleton(Configuration);
}

您可以在docs或various blogs上阅读有关配置的更多信息