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");
}
}
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"];
这通常发生在vscode中，因为配置launch.json的方式不同。
基于这个答案，我不得不重新配置基本路径，配置正在搜索的DLL的路径，因为默认设置是可选的，很难在.net core 3.1和net 5.0应用程序中追踪到这一点。以下是我如何重新配置的
Program.cs:
using System;
using System.IO;
using System.Reflection;
using Microsoft.Extensions.Configuration;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
namespace API
{
public class Program
{
public static int Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
return 0;
}
public static IHostBuilder CreateHostBuilder(string[] args)
{
return Host.CreateDefaultBuilder(args)
.ConfigureAppConfiguration(c =>
{
var codeBase = Assembly.GetExecutingAssembly().Location;
var uri = new UriBuilder(codeBase);
var path = Uri.UnescapeDataString(uri.Path);
var assembyDirectory = Path.GetDirectoryName(path);
c.SetBasePath(assembyDirectory);
})
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
})
;
}
}
}
我可以在Startup.cs中访问配置:
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Model;
namespace API
{
public class Startup
{
public IConfiguration Configuration { get; }
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
var myOptions = Configuration.To<ApiConfig>();
services.AddAuthentication(myOptions.Secret);
services.AddControllers();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints => { endpoints.MapControllers(); });
}
}
}
