For Loop works not working, or giving error. Works when conditions are reversed - vb.net

Question

I don't know if its the late hour, but I am working on the following array For Loop:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim pboxes() As PictureBox = {picMainImage, picImage2, picImage3, picImage4}
For i As Integer = 0 To pboxes.Count - 1
If pboxes(i).Image Is My.Resources.list Then
pboxes(i).Image = Nothing
End If
Next
End Sub
The loop is supposed to check if any of the picture boxes in the array have an Image called List stored on the Resources folder in them. If it does, set the image to Nothing. However, I run it and nothing happens., no errors, nothing.
So I reversed my For Loop as follows to see what happens:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim pboxes() As PictureBox = {picMainImage, picImage2, picImage3, picImage4}
For i As Integer = 0 To pboxes.Count - 1
If pboxes(i).Image Is Nothing Then
pboxes(i).Image = My.Resources.list
End If
Next
End Sub
This works but is not what I want, I want the opposite.
What am I doing wrong here?

Answer 1

One option is if you set the pictures in the box programatically, set My.Resources.list to be referenced by a global variable, ie Public pbList = My.Resources.list
Then, when you set the picture initially, use that variable, so: picMainImage.Image = pbList
Finally, in your If statement, you should then be able to check If pboxes(i) is pbList Then...
Once it becomes a variable, it seems to become static and therefore wherever you use it, it will always be the same.
EDIT: some actual code that I used a few months back:
In the module (outside sub)
Public pbimage As System.Drawing.Image = My.Resources.placeholder
Then in the Sub
If imgpath <> "" Then
Me.lblImg.ImageLocation = imgpath
Else
Me.lblImg.ImageLocation = Nothing
Me.lblImg.Image = pbimage
End If
and then this is what I use for all pictures without issues (its a function that I have run when you click on an image - if its the placeholder then you can browse for an image and save it to a data folder, otherwise it does nothing)
Private Sub changeImg(sender As Object, e As MouseEventArgs) Handles {ALL YOUR IMAGES}.Click
If TypeOf sender Is PictureBox Then
If DirectCast(sender, PictureBox).Image Is pbimage Then
Dim ofd As New OpenFileDialog
ofd.Title = "Please select image"
ofd.Filter = "Image Files|*.jpg"
If ofd.ShowDialog() = Windows.Forms.DialogResult.OK Then
Dim rn As New Random
Dim r As Long = rn.Next(111111, 999999)
Dim newfilename As String = My.Settings.dataPath & r.ToString & Format(Now, "ddmmyy") & ".jpg"
Try
FileCopy(ofd.FileName, newfilename)
DirectCast(sender, PictureBox).ImageLocation = newfilename
Catch ex As Exception
MessageBox.Show("Check permissions to the Data folder", "Permissions error")
End Try
End If
End If
End If
End Sub

Answer 2

Images cannot be compared that way because the image is copied into memory and will always be different even if the pixels match. Compare the pixels directly to find out if the image is the same.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim pboxes() As PictureBox = {picMainImage, picImage2, picImage3, picImage4}
For i As Integer = 0 To pboxes.Count - 1
If IsSameImage(pboxes(i).Image, My.Resources.list) = True Then
pboxes(i).Image = Nothing
End If
Next
End Sub
Public Function IsSameImage(ByVal oBitmap1 As Bitmap, ByVal oBitmap2 As Bitmap) As Boolean
For x = 0 To oBitmap1.Width - 1
For y = 0 To oBitmap2.Height - 1
If Not oBitmap1.GetPixel(x, y) = oBitmap2.GetPixel(x, y) Then
Return False
End If
Next
Next
Return True
End Function