title: Why "this" works but "Form.Activeform" throws NullRefernceException?
body: <p>if this keyword refers to the current instance of the class as instanced in  program class(Application.Run(new Form1())) </p>
  
  <p>we can reach it's properties with this keyword   </p>
  
  <pre><code>        this .Text = "debuggging";
          this .Opacity = 54;
          this .ShowIcon = true;
          this .Size = new Size(100, 100);
  </code></pre>
  
  <p>why cant ı reach it with Form1.ActiveForm.<em>*</em>(All properties)</p>
  
  <p>just out of curiosity  but why </p>
  
  <p>when coded like this   </p>
  
  <pre><code>        Form1.ActiveForm.Text = "debugla";
          Form1.ActiveForm.Opacity = 54;
          Form1.ActiveForm.ShowIcon = true;
          Form1.ActiveForm.Size = new Size(100, 100);
  </code></pre>
  
  <p>and activeform must bring us the currently active form used </p>
  
  <p>it throws nullreference exception     why    ?</p>