title: How to "Add a new data source" in a WPF Core application?
body: <p><strong>Question:</strong> How to "Add a new data source" in a WPF Core application?
   <br>
  I performed:<br>
   - Created a WPF Core application;<br>
   - Added the class <code>CntDBSchool</code>;<br>
   - Added the class <code>Student</code>;<br>
   - Menu <code>Project</code> //" Add a new data source ";<br>
   - Result: there is no class <code>Student</code>;<br>
   
  <a href="https://i.stack.imgur.com/z1wkV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/z1wkV.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/zkNBG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zkNBG.png" alt="enter image description here"></a></p>
  
  <p><strong>Class <code>CntDBSchool</code>.</strong></p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Text;
  using Microsoft.EntityFrameworkCore;
   
  namespace WpfApp.Models
  {
      class CntDBSchool: DbContext
      {
          public virtual DbSet &lt;Student&gt; Student {get; set; }
      }
  }
  </code></pre>
  
  <p><strong>Class <code>Student</code>.</strong></p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Text;
   
  namespace WpfApp.Models
  {
      class Student
      {
          public int StudentID {get; set; }
          public string StudentName {get; set; }
          public Nullable &lt;int&gt; StandardId {get; set; }
          public byte [] RowVersion {get; set; }
      }
  }
  </code></pre>
  
  <p> 
  <strong>Table <code>Student</code>.</strong></p>
  
  <pre><code> CREATE TABLE [dbo]. [Student] (
    [StudentID] int IDENTITY (1,1) NOT NULL,
    [StudentName] varchar (50) COLLATE Latin1_General_CI_AI NULL,
    [StandardId] int NULL,
    [RowVersion] timestamp NOT NULL,
    CONSTRAINT [PK_Student] PRIMARY KEY CLUSTERED ([StudentID])
  WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
  ON [PRIMARY],
    CONSTRAINT [FK_Student_Standard] FOREIGN KEY ([StandardId]) REFERENCES [dbo]. [Standard] ([StandardId]) ON DELETE CASCADE ON UPDATE NO ACTION
  )
  ON [PRIMARY]
  </code></pre>
  
  <p> 
   
  When I do the same in the WPF Framework application, the Student class is present in the Add New Data Source window.<br>
  I do:<br>
   - Created a WPF Framework application;<br>
   - Created <code>Model ADO.NET EDM</code>;<br>
   - In the file <code>DBModel.tt</code> replaced:<br>
   - - line - 296 replaced <code>ICollection</code> with<code>ObservableCollection</code>;<br>
   - - line - 484 replaced <code>ICollection</code> with<code>ObservableCollection</code>;<br>
   - - line - 51 replaced <code>HashSet</code> with<code>ObservableCollection</code>;<br>
   - - lines - 431 replaced <code>System.Collections.Generic</code> with<code>System.Collections.ObjectModel</code>;<br>
   - Menu <code>Project</code> //" Add a new data source ";<br>
   - Result: the class <code>Student</code> is present;<br>
  <a href="https://i.stack.imgur.com/XkYLT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XkYLT.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/7BRCG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7BRCG.png" alt="enter image description here"></a></p>