Something's wrong with GDI API in VB6

[Ben321]

Ok so I made a class (.cls file) for handling graphics. Here's the declarations in my class.

Private Declare Function GetDIBits Lib "GDI32.dll" ( _
    ByVal hDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, _
    ByVal nNumScans As Long, ByRef lpBits As Any, _
    ByRef lpBI As BitmapInfo, ByVal wUsage As Long) As Long
Private Declare Function SetDIBits Lib "GDI32.dll" ( _
    ByVal hDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, _
    ByVal nNumScans As Long, ByRef lpBits As Any, _
    ByRef lpBI As BitmapInfo, ByVal wUsage As Long) As Long
 
Private Type BitmapInfoHeader
    biSize As Long
    biWidth As Long
    biHeight As Long
    biPlanes As Integer
    biBitCount As Integer
    biCompression As Long
    biSizeImage As Long
    biXPelsPerMeter As Long
    biYPelsPerMeter As Long
    biClrUsed As Long
    biClrImportant As Long
End Type

Private Type BitmapInfo
    bmiHeader As BitmapInfoHeader
    bmiColors(255) As Long
End Type

Dim DIBinfo As BitmapInfo

Dim MyPic As PictureBox

Here's the functions in the class that are having a problem

Public Property Set PictBox(ByRef PicBox As PictureBox)
Set MyPic = PicBox
End Property


Public Sub GetPixels()
DIBinfo.bmiHeader.biSize = Len(DIBinfo.bmiHeader)
GetDIBits MyPic.hDC, MyPic.Image, 0, 0, ByVal 0&, DIBinfo, 0
MsgBox Dibinfo.bmiHeader.biWidth
MsgBox Dibinfo.bmiHeader.biHeight
End Sub

Now the initial size of my Picture1 picture box is 256x224.
Now the code I'm using in my form in the command button's "click" event, to test my API functions is

Dim BM As New Bitmap 'Bitmap is the name of my class

Set BM.PictBox = Picture1
BM.GetPixels
 'The first MsgBox shows "256" and the second one shows "224"

Picture1.Height=80
Set BM.PictBox = Picture1
BM.GetPixels
 'As expected, the GDI API correctly reads the new smaller size of Picture1 and the first MsgBox shows "256" and the second one shows "80"


Picture1.Height=224
Set BM.PictBox = Picture1
BM.GetPixels
 'Now the unexpected happens.
 'The GDI API INCORRECTLY reads the new larger size of Picture1 and as a result it "thinks" that the height hasn't changed,
 'so while the first MsgBox shows "256", second one INCORRECTLY still shows "80"

What is going on? Please help. Am I just overlooking something very obvious and easy to correct here?