Add event to dynamically created button - vb.net

Question

I have 4 picture boxes on my form. Whenever a new picture is selected the next available box populated and a button is created within that picture box. I would like that button to be able to delete the image within that particular picturebox. I know how to create an event handler and then add the address to the button, what I do not know how to do is how to write the code so as to actually delete the assigned image on the assigned box. Here is my code to load the pictures and create the button:
Private Sub btnAddImage_Click(sender As Object, e As EventArgs) Handles btnAddImage.Click, btnUploadImage.Click 4
Dim btn As Button = New Button
btn.Text = "Remove Image"
'Procedure places the pictures in each empty picturebox in sequence
ofdBrowsePictures.Multiselect = False
ofdBrowsePictures.Title = "Select Image to Upload"
ofdBrowsePictures.Filter = "Image Files |*.jpg*"
If ofdBrowsePictures.ShowDialog() = Windows.Forms.DialogResult.OK Then
'create array of each picture box and check if they are empty
'Check if the picturebox contains a tag with the image path
Dim PBs() As PictureBox = {picMainImage, picImage2, picImage3, picImage4}
Dim nextPB = PBs.Where(Function(x) IsNothing(x.Image)).FirstOrDefault
If Not IsNothing(nextPB) Then
'if the box does not contain a image path, then place the picture on that box
nextPB.ImageLocation = ofdBrowsePictures.FileName
nextPB.Tag = nextPB.ImageLocation.ToString
'add a button
nextPB.Controls.Add(btn)
'Create a border style on the image
nextPB.BorderStyle = BorderStyle.FixedSingle
End If
End If
End Sub

Answer 1

what I do not know how to do is how to write the code so as to actually delete the assigned image on the assigned box
I assume "delete image" means remove from the picture box, not delete from disk.
' what is 4???
Private Sub btnAddImage_Click(sender As Object,
e As EventArgs) Handles btnAddImage.Click, btnUploadImage.Click 4
Dim btn As Button = New Button
btn.Text = "Remove Image"
' bla bla bla set the imagelocation
AddHandler btn.Click, AddressOf RemoveImage_Click
pb1.Controls.Add(btn) ' btn.parent = this pb
End Sub
Private Sub RemoveImage_Click(sender As Object, e As EventArgs) Handles Button9.Click
Dim btn As Button = CType(sender, Button)
' clear image
CType(btn.Parent, PictureBox).ImageLocation = ""
RemoveHandler btn.Click, AddressOf RemoveImage_Click
' remove the control
pb1.Controls.Remove(btn)
' if you remove a control, dispose of it
btn.Dispose()
End Sub
I am not sure I would invoke the dialog before checking for the next PB (nor would I create the new Button), since you seem to want to do nothing if there is no nextPB to play with.
For more information about Disposing of controls you Remove, see:
Memory Leak
What are Parking Windows
Adding / removing controls
Basically, forms dispose of controls when you close them. If you Remove a control, the form no longer has a reference and cannot. As a result, you should be disposing them.

Answer 2

Either of these clear a picturebox image set with ImageLocation:
PictureBox1.Image = Nothing
PictureBox1.ImageLocation = ""
PictureBox1.ImageLocation = String.Empty