ASP.NET Web API userSecrets 连接字符串

Question

This might seem like a silly problem but I'm still new to ASP.NET Core Web API. I have the following Program.cs file Program.cs

using CompanionApp.Models;
using Microsoft.EntityFrameworkCore;
using System.Text.Json.Serialization;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddControllers().AddJsonOptions(x =>
                x.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles);


IConfiguration config = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .AddEnvironmentVariables()
    .AddCommandLine(args)
    .AddUserSecrets<Program>(true)
    .Build();

string connectionString = config["ConnectionStrings:DevCompanionAppDB"];
Console.WriteLine(connectionString);

builder.Services.AddDbContext<CompanionAppDBContext>(options =>
        options.UseSqlServer(config.GetConnectionString(connectionString)));

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseAuthorization();

app.MapControllers();

app.Run();

I moved my connection string to a secrets.json using visual studio. When debugging the code, the connection string gets loaded correctly I can print it to the console, however, when I try to use it here:

builder.Services.AddDbContext<CompanionAppDBContext>(options =>
        options.UseSqlServer(config.GetConnectionString(connectionString)));

I get the following error:

System.ArgumentNullException
  HResult=0x80004003
  Message=Value cannot be null. (Parameter 'connectionString')
  Source=Microsoft.EntityFrameworkCore.SqlServer
  StackTrace:
   at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName)
   at Microsoft.EntityFrameworkCore.SqlServerDbContextOptionsExtensions.UseSqlServer(DbContextOptionsBuilder optionsBuilder, String connectionString, Action`1 sqlServerOptionsAction)
   at Program.<>c__DisplayClass0_0.<<Main>$>b__1(DbContextOptionsBuilder options) in C:\Users\fadih\AUB Companion App\AUB Companion App REST API\Program.cs:line 29
   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass1_0`2.<AddDbContext>b__0(IServiceProvider p, DbContextOptionsBuilder b)
   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.CreateDbContextOptions[TContext](IServiceProvider applicationServiceProvider, Action`2 optionsAction)
   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass17_0`1.<AddCoreServices>b__0(IServiceProvider p)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite callSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite callSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass2_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.<>c__DisplayClass7_0.<CreateActivator>b__0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.<>c__DisplayClass6_0.<CreateControllerFactory>g__CreateController|0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()

In the locals window in visual studio, the connection string is not null as well. Am I missing something?

appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",

  "ConnectionStrings": {
    "CompanionAppDB": ""
  }
}

The connection string is empty here because I have on my Azure portal which overrides this one.

Answer 1

try

string connectionString = config["ConnectionStrings:DevCompanionAppDB"];
builder.Services.AddDbContext<CompanionAppDBContext>(options =>
        options.UseSqlServer(connectionString));