title: asp.net core and EF core error while add migration
body: <p>In a asp.net core app, I am trying to to migration for EF code fist.</p>
  
  <p>I got below errors,</p>
  
  <blockquote>
    <p>An error occurred while calling method 'ConfigureServices' on startup
    class 'WebAppHandOn.Startup'. Consider using IDbContextFactory to
    override the initialization of the DbContext at design-time. Error:
    Could not load file or assembly 'Microsoft.AspNetCore.Routing,
    Version=1.0.1.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or
    one of its dependencies. The located assembly's manifest definition
    does not match the assembly reference. (Exception from HRESULT:
    0x80131040)</p>
    
    <p>No parameterless constructor was found on 'ApplicationDbContext'.
    Either add a parameterless constructor to 'ApplicationDbContext' or
    add an implementation of 'IDbContextFactory' in
    the same assembly as 'ApplicationDbContext'.</p>
  </blockquote>
  
  <p>Here are the different code files,</p>
  
  <ol>
  <li><p>Startup Class</p>
  
  <pre><code>public void ConfigureServices(IServiceCollection services)
  {
      // Add framework services.
      services.AddMvc();
  
      // Add EntityFramework's Identity support.
      services.AddEntityFramework();
  
      // Add ApplicationDbContext.
      services.AddDbContext&lt;ApplicationDbContext&gt;(options =&gt; options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
  }
  </code></pre></li>
  <li><p>ApplicationDBContext Class</p>
  
  <pre><code>public class ApplicationDbContext : DbContext {
      #region Constructor
  
      public ApplicationDbContext(DbContextOptions options) : base(options)
      {
      }
      #endregion Constructor
  
      #region Methods
      protected override void OnModelCreating(ModelBuilder modelBuilder)
      {
          base.OnModelCreating(modelBuilder);
      }
      #endregion Methods
  
      #region Properties
      public DbSet&lt;Item&gt; Items { get; set; }
      public DbSet&lt;Comment&gt; Comments { get; set; }
      public DbSet&lt;ApplicationUser&gt; Users { get; set; }
      #endregion Properties
  }
  </code></pre></li>
  <li>Project.json Class</li>
  </ol>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code> {
        "dependencies": {
       "Microsoft.AspNetCore.Mvc": "1.0.0",
      "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
      "Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
      "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
      "Microsoft.Extensions.Configuration.FileExtensions": "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.AspNetCore.Diagnostics": "1.0.0",
      "Microsoft.AspNetCore.Routing": "1.0.0",
      "Microsoft.AspNetCore.Authentication.JwtBearer": "1.0.0",
      "Microsoft.AspNetCore.StaticFiles": "1.0.0",
      "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
      "Newtonsoft.Json": "9.0.1",
      "Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.0.0",
      "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0",
      "Microsoft.EntityFrameworkCore": "1.0.0",
      "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0",
      "Microsoft.EntityFrameworkCore.Design": "1.0.0-preview2-final",
      "TinyMapper": "2.0.8"
    },
  
    "tools": {
      "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
      "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"
    },</code></pre>
  </div>
  </div>
  </p>