不确定我在这里错过了什么,但我无法从我的应用程序设置中获得值。Json在我的。net核心应用程序。我有我的appsettings。json:

{
    "AppSettings": {
        "Version": "One"
    }
}

启动:

public class Startup
{
    private IConfigurationRoot _configuration;
    public Startup(IHostingEnvironment env)
    {
        _configuration = new ConfigurationBuilder()
    }
    public void ConfigureServices(IServiceCollection services)
    {
      //Here I setup to read appsettings        
      services.Configure<AppSettings>(_configuration.GetSection("AppSettings"));
    }
}

模型:

public class AppSettings
{
    public string Version{ get; set; }
}

控制器:

public class HomeController : Controller
{
    private readonly AppSettings _mySettings;

    public HomeController(IOptions<AppSettings> settings)
    {
        //This is always null
        _mySettings = settings.Value;
    }
}

_mySettings总是空的。我是不是遗漏了什么?


当前回答

花了一个小时试图解决同样的问题,我的解决方案是为appconfig添加PreserveNewest/CopyAlways。csproj中的Json

<None Update="appsettings.json">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>

其他回答

我认为最好的选择是:

创建一个模型类作为配置模式 在DI注册: services.Configure (Configuration.GetSection(“democonfig”)); 从控制器中的DI中获取模型对象的值: private readonly myConfig; (IOptions<your_model> configOps) { 这一点。myConfig = configOps.Value; }

再加上David Liang对Core 2.0的回答——

appsettings。json文件链接到ASPNETCORE_ENVIRONMENT变量。

ASPNETCORE_ENVIRONMENT可以设置为任何值,但是框架支持三个值:Development、Staging和Production。如果没有设置ASPNETCORE_ENVIRONMENT,它将默认为Production。

对于这三个值,这些appsettings.ASPNETCORE_ENVIRONMENT。json文件支持开箱即用- appsettings.Staging。appsettings.Development.json和appsettings.Production.json

以上三个应用程序设置json文件可用于配置多个环境。

示例- appsettings.Staging.json

{
    "Logging": {
        "IncludeScopes": false,
        "LogLevel": {
            "System": "Information",
            "Microsoft": "Information"
        }
    },
    "MyConfig": "My Config Value for staging."
}

使用Configuration["config_var"]检索任何配置值。

public class Startup
{
    public Startup(IHostingEnvironment env, IConfiguration config)
    {
        Environment = env;
        Configuration = config;
        var myconfig = Configuration["MyConfig"];
    }

    public IConfiguration Configuration { get; }
    public IHostingEnvironment Environment { get; }
}

. net core 3。X

不需要创建新的模型并在Startup.cs中设置。

控制器 添加新包-使用Microsoft.Extensions.Configuration;

public class HomeController : Controller
{
    private readonly IConfiguration _mySettings;

    public HomeController (IConfiguration mySettings)
    {
         _mySettings= mySettings;
    }
 
    //ex: you can get value on below function 
    public IEnumerable<string> Get()
    {
        var result = _config.GetValue<string>("AppSettings:Version"); // "One"
        return new string[] { result.ToString() };
    }
}

假设在appsettings.json中有这样的值。

  "MyValues": {
    "Value1": "Xyz"
  }

方法一:不进行依赖注入

在.cs文件中:

static IConfiguration conf = (new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json").Build());
public static string myValue1= conf["MyValues:Value1"].ToString();

方法二:依赖注入(推荐)

在Startup.cs文件:

public IConfiguration Configuration { get; }
public Startup(IConfiguration configuration)
{
     Configuration = configuration;
}
public void ConfigureServices(IServiceCollection services)
{
     ...
     services.AddServices(Configuration);
}

在你的控制器中:

public class TestController : ControllerBase
{
    private string myValue1 { get; set; }
    public TestController(IConfiguration configuration)
    {
         this.myValue1 = configuration.GetValue<string>("MyValues:Value1");
    }
}

在我的例子中,它就像在Configuration对象上使用Bind()方法一样简单。然后将对象作为单例添加到DI中。

var instructionSettings = new InstructionSettings();
Configuration.Bind("InstructionSettings", instructionSettings);
services.AddSingleton(typeof(IInstructionSettings), (serviceProvider) => instructionSettings);

Instruction对象可以非常复杂。

{  
 "InstructionSettings": {
    "Header": "uat_TEST",
    "SVSCode": "FICA",
    "CallBackUrl": "https://UATEnviro.companyName.co.za/suite/webapi/receiveCallback",
    "Username": "s_integrat",
    "Password": "X@nkmail6",
    "Defaults": {
    "Language": "ENG",
    "ContactDetails":{
       "StreetNumber": "9",
       "StreetName": "Nano Drive",
       "City": "Johannesburg",
       "Suburb": "Sandton",
       "Province": "Gauteng",
       "PostCode": "2196",
       "Email": "ourDefaultEmail@companyName.co.za",
       "CellNumber": "0833 468 378",
       "HomeNumber": "0833 468 378",
      }
      "CountryOfBirth": "710"
    }
  }