title: PictureBox with transparent background
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/4144371/a-picturebox-problem">A PictureBox Problem</a>  </p>
  </blockquote>
  
  
  
  <p>I have a <code>TabPage</code> which hosts some custom <code>PictureBox</code> controls. What I do here is drawing some IC packages which user can click on theire pins to get some info. User can add multiple of this pictureboxes to the tabpage and move them around in the tabpage.</p>
  
  <p>My problem is that this pictureboxes are transparent, only when they are not over each other. In the image below you see two of this pictureboxes added to tabpage. The tabpage has a blue background, in fact, it doesnt matter what color it has, the pictureboxes will have theire undrawn areas transparent to the tabpage:</p>
  
  <p><img src="https://i.stack.imgur.com/O5c1O.png" alt="enter image description here"></p>
  
  <p>But as soon as I move any of thise pictureboxes above another, it will not be transparent anymore:</p>
  
  <p><img src="https://i.stack.imgur.com/oNqKf.png" alt="enter image description here"></p>
  
  <p>This is the code that produces raw <code>Image</code> that I will draw on it:                                   </p>
  
  <pre><code>    //Setting up image area
      Image = new Bitmap(requiredImageWidth, requiredImageHeight, PixelFormat.Format32bppArgb);
      Image.MakeTransparent();
  </code></pre>
  
  <p>The rest are default settings I didnt change anything else. What do you think causing this behaviour?</p>