Option Explicit

Public Type RGBQUAD
  rgbBlue As Byte
  rgbGreen As Byte
  rgbRed As Byte
  rgbReserved As Byte
End Type

Public 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

Public Type BITMAPINFO
  bmiHeader As BITMAPINFOHEADER
  bmiColors As RGBQUAD
End Type

Public Declare Function CreateDIBSection Lib "gdi32" ( _
      ByVal hdc As Long, pBitmapInfo As BITMAPINFO, _
      ByVal un As Long, ByVal lplpVoid As Long, _
      ByVal handle As Long, ByVal dw As Long) As Long

Public Declare Function GetWindowRect Lib "user32" ( _
      ByVal hwnd As Long, lpRect As RECT) As Long

Public Declare Function GetDC Lib "user32" ( _
      ByVal hwnd As Long) As Long
      
Public Declare Function ReleaseDC Lib "user32" ( _
      ByVal hwnd As Long, ByVal hdc As Long) As Long

Public Declare Function BitBlt Lib "gdi32" ( _
      ByVal hDestDC As Long, ByVal X As Long, _
      ByVal Y As Long, ByVal nWidth As Long, _
      ByVal nHeight As Long, ByVal hSrcDC As Long, _
      ByVal xSrc As Long, ByVal ySrc As Long, _
      ByVal dwRop As Long) As Long

Public Declare Function CreateCompatibleDC Lib "gdi32" ( _
      ByVal hdc As Long) As Long

Public Declare Function DeleteDC Lib "gdi32" ( _
      ByVal hdc As Long) As Long

Public Declare Function SelectObject Lib "gdi32" ( _
      ByVal hdc As Long, ByVal hObject As Long) As Long

Function CreateBMPFromWindow(Form_hwnd As Long) As Long
  Dim rc As RECT
  Dim X As Integer
  Dim Y As Integer
  Dim cx As Integer
  Dim cy As Integer
  Dim hdcScreen As Long
  Dim hdcMemory As Long
  Dim Bitmap As Long

  GetWindowRect Form_hwnd, rc
  X = rc.Left
  Y = rc.Top
  cx = rc.Right - rc.Left
  cy = rc.Bottom - rc.Top

  hdcScreen = GetDC(0)

  hdcMemory = CreateCompatibleDC(0)

  Bitmap = CreateDibBMP(hdcScreen, cx, cy, 16)

  SelectObject hdcMemory, Bitmap

  BitBlt hdcMemory, 0, 0, cx, cy, hdcScreen, X, Y, vbSrcCopy

  DeleteDC hdcMemory
  ReleaseDC 0, hdcScreen
    
  CreateBMPFromWindow = Bitmap
End Function

Function CreateDibBMP(hdc As Long, _
      ByVal w As Long, ByVal h As Long, _
      bpp As Integer) As Long

  Dim bih As BITMAPINFO

  bih.bmiHeader.biSize = 40
  bih.bmiHeader.biWidth = w
  bih.bmiHeader.biHeight = h
  bih.bmiHeader.biBitCount = bpp
  bih.bmiHeader.biPlanes = 1
  bih.bmiHeader.biCompression = 0
  bih.bmiHeader.biSizeImage = 0
  bih.bmiHeader.biClrUsed = 0

  CreateDibBMP = CreateDIBSection(hdc, bih, 0, 0, 0, 0)
End Function