title: System.Windows.Forms assembly reference in VS Code
body: <p>To set up my development framework for c# in visual studio code,
  I want to use the <code>System.Windows.Forms</code> refernce in order to set up a window.</p>
  
  <p><strong>Code:</strong></p>
  
  <pre><code>using System;
  using System.Collections;
  using System.Windows.Forms;
  namespace Softwaredevelopment
  {
     public partial class Form1 : Form
     {
        public Form1()
        {
          //tbd
        }
     }
  }
  </code></pre>
  
  <p>I get the error:</p>
  
  <blockquote>
    <p>Missing Assembly Reference.</p>
  </blockquote>
  
  <p>What do I have to add in the <code>project.json</code> file or the <code>.csproj</code> file
  to get the ability to create a window.</p>