Why isn’t my PictureBox background transparent?

[groston]

I have a VB.net forms application. The majority of the form is a DataGridView with the cells having a variety of background colors. In the application, when a button is clicked, a PictureBox is created and it is filled with a PNG image. The image is a circle – black outline with a white interior and a transparent background.

Following is the code used to place the picture box:

Dim xpos As Integer = <some number>
Dim yPos As Integer = <some number>
Dim pba as PictureBox = New PictureBox
pba.BackColor = Color.Transparent
pba.Height = 70
pba.Width = 70
pba.Location = New Point(xPos, yPos)
pba.Image = My.Resources.circle
Controls.Add(pba)
pba.BringToFront()

All of this works fine, but the area outside the circle and inside the PictureBox is white, not transparent. I have searched, but have found nothing to address this issue. Did I miss something obvious? Please help.

[jmcilhinney]

There is no real transparency in Windows Forms. When you make a control transparent, what actually happens is that the control copies the area of its parent that it is covering and paints that in its background. Because your form is the parent of the PictureBox, what you're seeing is the form painted in its background. You may have to use GDI+ to draw the image over the DataGridView instead, although that may be complex because you may have to draw in each cell individually. I'm not sure that you can just draw over the top of the grid as a whole.

[.paul.]

...I'm not sure that you can just draw over the top of the grid as a whole.

You can draw over the dgv. Just handle the Paint event, and use e.Graphics

[jmcilhinney]

You can draw over the dgv. Just handle the Paint event, and use e.Graphics

Just tested and can confirm. The one exception is when editing a cell, the editing control will be displayed over the grid and so will obscure the drawing. If that's an issue, you'd have to handle the Paint event of the editing control too, although I'm not sure that a TextBox supports drawing over it anyway.

[Delaney]

I made a game in the past with transparent token in picturebox who move over an other picturebox. I used PNG files who allow transparency background

here is my test project for the movement if it can help : (project is to large for the local upload so here is a link )

https://www.swisstransfer.com/d/b280...1-2c490c425219

[.paul.]

I’ve written a few games that use a dgv with graphics drawn on it.
Have a look at my compiled games, and guess which ones use a dgv…