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?
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");
}
}
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; }
}
只需创建一个AnyName.cs文件并粘贴以下代码。
using System;
using System.IO;
using Microsoft.Extensions.Configuration;
namespace Custom
{
static class ConfigurationManager
{
public static IConfiguration AppSetting { get; }
static ConfigurationManager()
{
AppSetting = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("YouAppSettingFile.json")
.Build();
}
}
}
必须替换YouAppSettingFile。Json文件名与您的文件名。
您的.json文件应该如下所示。
{
"GrandParent_Key" : {
"Parent_Key" : {
"Child_Key" : "value1"
}
},
"Parent_Key" : {
"Child_Key" : "value2"
},
"Child_Key" : "value3"
}
现在你可以使用它了。
不要忘记在你想要使用的类中添加引用。
using Custom;
检索值的代码。
string value1 = ConfigurationManager.AppSetting["GrandParent_Key:Parent_Key:Child_Key"];
string value2 = ConfigurationManager.AppSetting["Parent_Key:Child_Key"];
string value3 = ConfigurationManager.AppSetting["Child_Key"];
我在WPF中遇到了类似的问题。NET Framework 5.0)
我所要做的就是登记。
services.AddSingleton<IConfiguration>(_configuration);
配置本身是这样配置的(在App.xaml.cs中):
var builder = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
_configuration = builder.Build();