经过大量研究，这适用于（在 ASPNetCore 2.2 中）从静态类访问 appsettings.json 配置，但由于某种原因 appsettings.development.json 不再正确加载，但它可能是我项目中的其他东西搞砸了. reloadOnChange 确实有效。作为奖励，它还具有 IHostingEnvironment 和 IHttpContextAccessor。虽然这可行，但我最近决定切换回更多的 DI 方法来遵循其他人提到的范式转变。
所以这是在静态类中访问一些 DI 内容（包括配置）的众多方法之一：
AppServicesHelper.cs：
public static class AppServicesHelper
{
static IServiceProvider services = null;
/// <summary>
/// Provides static access to the framework's services provider
/// </summary>
public static IServiceProvider Services
{
get { return services; }
set
{
if (services != null)
{
throw new Exception("Can't set once a value has already been set.");
}
services = value;
}
}
/// <summary>
/// Provides static access to the current HttpContext
/// </summary>
public static HttpContext HttpContext_Current
{
get
{
IHttpContextAccessor httpContextAccessor = services.GetService(typeof(IHttpContextAccessor)) as IHttpContextAccessor;
return httpContextAccessor?.HttpContext;
}
}
public static IHostingEnvironment HostingEnvironment
{
get
{
return services.GetService(typeof(IHostingEnvironment)) as IHostingEnvironment;
}
}
/// <summary>
/// Configuration settings from appsetting.json.
/// </summary>
public static MyAppSettings Config
{
get
{
//This works to get file changes.
var s = services.GetService(typeof(IOptionsMonitor<MyAppSettings>)) as IOptionsMonitor<MyAppSettings>;
MyAppSettings config = s.CurrentValue;
return config;
}
}
}
}
Startup.cs：
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public void ConfigureServices(IServiceCollection services)
{
//...
services.AddHttpContextAccessor();//For HttpContext.
// Register the IOptions object
services.Configure<MyAppSettings>(Configuration.GetSection(nameof(MyAppSettings)));
//Explicitly register the settings object by delegating to the IOptions object so that it can be accessed globally via AppServicesHelper.
services.AddSingleton(resolver => resolver.GetRequiredService<IOptionsMonitor<MyAppSettings>>().CurrentValue);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
//...
AppServicesHelper.Services = app.ApplicationServices;
//...
}
控制器：
public class MyController: Controller
{
public MyController()
{
}
public MyAppSettings Config => AppServicesHelper.Config;
public async Task<IActionResult> doSomething()
{
testModel tm = await myService.GetModel(Config.Setting_1);
return View(tm);
}
}
另一个类库：
public static class MyLibraryClass
{
public static string GetMySetting_ => AppServicesHelper.Config.Setting_1;
public static bool IsDev => AppServicesHelper.HostingEnvironment.IsDevelopment();
}
MyAppSettings.cs 是映射到 appsettings.json 中的 MyAppSettings 部分的任何类：
public class MyAppSettings
{
public string Setting_1 {get;set;}
}
appsettings.json：
{
"Logging": {
"LogLevel": {
"Default": "Warning"
}
},
"AllowedHosts": "*",
"MyAppSettings": {
"Setting_1": "something"
}
}