Is it possible to have two overlapping PictureBox controls with transparent images?

Question

Having two overlapping PictureBox controls, I'm trying to make the transparent areas of the picture box let the controls below (in the z-order) being visible.

Even after trying what Microsoft suggests, I cannot get the desired result.

This is what I currently have:

And this is what I want:

So my question is:

Any way to achieve my desired result with two PictureBox controls (or with another way) that overlap each other and let the transparent areas shine through?

Update:

Actually I solved it by using this answer to the the SO question "Transparent images with C# WinForms".

Solution 1

Try this

private void Form1_Load(object sender, EventArgs e)
{
  // Transparent background...  
  pictureBoxOverlay.BackColor = Color.Transparent;

  // Change parent for overlay PictureBox...
  pictureBoxOverlay.Parent    = pictureBoxMain;

 // Change overlay PictureBox position in new parent...
 // pictureBoxOverlay.Location  = new Point(0, 0);
}

Result

Link

Solution 2

As far as I know, the transparency of a control depends on its parent control (As noted in the link you've given), meaning that in order to have the effect you are looking for, you need to have one picture box nested into another picture box which is impossible given that a picture box is not a container.

You can however, use a custom container control instead of a picture box for the parent image. The most basic control would be a panel. Just set the background image of the control and put the second picture box in it.

Another solution, would be to use one single picture box and manage the rendering manually.

This is by far the best solution as the pseudo-simulated transparency of the other method is quiet inefficient.

Comments

[Uwe Keim]

Thanks, this works unless the overlay picture box is clipped by the picture box. I need them to only partially overlapped.