Emmanuel Villegas Emmanuel Villegas - 4 months ago 283
C# Question

Could not load type 'Microsoft.Extensions.DependencyInjection.Extensions.ServiceCollectionExtensions'

I'm working with asp.net core 1.0 and trying to configure my dbcontext for migrations I got this exception Could not load type 'Microsoft.Extensions.DependencyInjection.Extensions.ServiceCollectionExtensions' from assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. somebody knows what may be happening or what am I missing?

thanks in advance, My files below:

my project.json

{
"dependencies": {
"Microsoft.NETCore.App": {
"version": "1.0.0",
"type": "platform"
},
"Microsoft.ApplicationInsights.AspNetCore": "1.0.0",
"Microsoft.AspNetCore.Diagnostics": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.0.0",
"Microsoft.AspNetCore.Razor.Tools": {
"version": "1.0.0-preview2-final",
"type": "build"
},
"Microsoft.EntityFrameworkCore.Design": {
"type": "build",
"version": "1.0.0-preview2-final"
},
"Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
"Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
"Microsoft.AspNetCore.StaticFiles": "1.0.0",
"Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
"Microsoft.Extensions.Configuration.Json": "1.0.0",
"Microsoft.Extensions.Logging": "1.0.0",
"Microsoft.Extensions.Logging.Console": "1.0.0",
"Microsoft.Extensions.Logging.Debug": "1.0.0",
"Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
"Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
"Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-rc2-final",
"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview1-final",
},

"tools": {
"BundlerMinifier.Core": "2.0.238",
"Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
"Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"
},

"frameworks": {
"netcoreapp1.0": {
"imports": [
"dotnet5.6",
"portable-net45+win8"
]
}
},

"buildOptions": {
"emitEntryPoint": true,
"preserveCompilationContext": true
},

"runtimeOptions": {
"configProperties": {
"System.GC.Server": true
}
},

"publishOptions": {
"include": [
"wwwroot",
"Views",
"Areas/**/Views",
"appsettings.json",
"web.config"
]
},

"scripts": {
"prepublish": [ "bower install", "dotnet bundle" ],
"postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
}
}


My Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using OdeToFood.Services;
using OdeToFood.Entities;
using Microsoft.EntityFrameworkCore;

namespace OdeToFood
{
public class Startup
{
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();

if (env.IsDevelopment())
{
// This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
builder.AddApplicationInsightsSettings(developerMode: true);
}
Configuration = builder.Build();
}

public IConfigurationRoot Configuration { get; }

// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.

services.AddMvc();

services.AddEntityFrameworkSqlServer()
.AddDbContext<OdeToFoodDbContext>(options => options.UseSqlServer("@Server = (localdb)\\MSSQLLocalDB; Database = OdeToFood; Trusted_Connection = True; MultipleActiveResultSets = true"));
services.AddSingleton(provider => Configuration);
services.AddApplicationInsightsTelemetry(Configuration);
services.AddScoped<IRestaurantData, InMemoryRestaurantData> ();

}

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();

app.UseApplicationInsightsRequestTelemetry();

if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseBrowserLink();
}
else
{
app.UseExceptionHandler("/Home/Error");
}

app.UseApplicationInsightsExceptionTelemetry();

app.UseStaticFiles();

app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
}
}
}


My dbContext.cs

using Microsoft.EntityFrameworkCore;

namespace OdeToFood.Entities
{
public class OdeToFoodDbContext:DbContext
{
public DbSet<Restaurant> Restaurants { get; set; }

//protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
//{
// optionsBuilder.UseSqlServer("@Server = (localdb)\\MSSQLLocalDB; Database = OdeToFood; Trusted_Connection = True; MultipleActiveResultSets = true");
//}
}
}

Answer

Your project.json is referencing an old version of this package:

"Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-rc2-final"

It should be:

"Microsoft.EntityFrameworkCore.SqlServer": "1.0.0"