title: Popover transparent child form on top of parent form in windows c#
body: <p><img src="https://i.stack.imgur.com/XgkAt.png" alt="enter image description here"></p>
  
  <p>I want to display transparent form having same height and width like parent form in winforms c# application.</p>
  
  <p>I am removing control box and border style properties of child form and want to display that form inside parent form in full height/width.
  I represented child form area in red border in uploaded image.</p>
  
  <p>I tried by setting height and width of child form on resize event of parent form but it couldn't work.</p>
  
  <pre><code>Form2 f2 = new Form2();
  f2.Height = this.Height;
  f2.Width = this.Width;
  f2.Show();
  </code></pre>
  
  <p>It is displaying child form but not in proper way as i want to fit it on parent form.</p>
  
  <p><strong>Why i need this?</strong></p>
  
  <p>I am using third party control on parent form and want to add lines on it, but that control is not supporting graphics property.
  So i am taking transparent form on top of that parent form and want to add graphics object like line, rectangle etc...</p>
  
  <p>I am putting image for reference.</p>
  
  <p>Please share your valuable thoughts to solve my problem.</p>
  
  <p>Thanks in advance.</p>