Create animation in dotNet with alpha-blending PNG images by calling API

Imports Microsoft.VisualBasic
Imports System
Imports System.Runtime.InteropServices

Namespace movepng
    Class Win32
        Public Enum Bool
            [False] = 0

            [True] = 1

        End Enum

        Public Structure Point
            Public x As Integer

            Public y As Integer


            Public Sub New(x As Integer, y As Integer)
                Me.x = x
                Me.y = y
            End Sub
        End Structure

        Public Structure Size
            Public cx As Integer

            Public cy As Integer


            Public Sub New(cx As Integer, cy As Integer)
                Me.cx = cx
                Me.cy = cy
            End Sub
        End Structure

        Public Structure BLENDFUNCTION
            Public BlendOp As Byte

            Public BlendFlags As Byte

            Public SourceConstantAlpha As Byte

            Public AlphaFormat As Byte

        End Structure

        Public Const ULW_ALPHA As Integer = 2

        Public Const AC_SRC_OVER As Byte = 0

        Public Const AC_SRC_ALPHA As Byte = 1


        <DllImportAttribute("user32.dll")> _
        Public Shared Function UpdateLayeredWindow(handle As IntPtr, hdcDst As IntPtr, ByRef pptDst As Point, ByRef psize As Size, hdcSrc As IntPtr, ByRef pprSrc As Point, crKey As Integer, ByRef pblend As BLENDFUNCTION, dwFlags As Integer) As Bool
        End Function

        <DllImportAttribute("user32.dll")> _
        Public Shared Function GetDC(handle As IntPtr) As IntPtr
        End Function

        <DllImportAttribute("user32.dll", ExactSpelling:=True)> _
        Public Shared Function ReleaseDC(handle As IntPtr, hDC As IntPtr) As Integer
        End Function

        <DllImportAttribute("gdi32.dll")> _
        Public Shared Function CreateCompatibleDC(hDC As IntPtr) As IntPtr
        End Function

        <DllImportAttribute("gdi32.dll")> _
        Public Shared Function DeleteDC(hdc As IntPtr) As Bool
        End Function

        <DllImportAttribute("gdi32.dll")> _
        Public Shared Function SelectObject(hDC As IntPtr, hObject As IntPtr) As IntPtr
        End Function

        <DllImportAttribute("gdi32.dll")> _
        Public Shared Function DeleteObject(hObject As IntPtr) As Bool
        End Function
    End Class
End Namespace