Visual Basic RBG画面からキャプチャ

Question

ビジュアルベーシックで画面をキャプチャし、それをピクセル値のRBG配列に変換するコードが必要です。かなり高速にする必要があります。

助けが必要ですか？

Answer 1

このコードは、ウィンドウまたはデスクトップ全体（仮想スクリーン）からのスクリーンショットをキャプチャし、それをカスタムピクチャボックスに描画します。

Private Type RECT 
    Left As Long 
    Top As Long 
    Right As Long 
    Bottom As Long 
End Type 

Private Declare Function GetSystemMetrics Lib "user32" (ByVal nIndex As Long) As Long 
Private Declare Function GetWindowRect Lib "user32" (ByVal hWnd As Long, lpRect As RECT) As Long 
Private Declare Function GetDesktopWindow Lib "user32"() As Long 

Private Declare Function GetWindowDC Lib "user32" (ByVal hWnd As Long) As Long 
Private 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 
Private Declare Function ReleaseDC Lib "user32" (ByVal hWnd As Long, ByVal hDC As Long) As Long 

Private Const SM_XVIRTUALSCREEN = 76 
Private Const SM_YVIRTUALSCREEN = 77 
Private Const SM_CYVIRTUALSCREEN = 79 
Private Const SM_CXVIRTUALSCREEN = 78 

Private Sub GetScreenshot(Optional ByVal hWnd As Long = 0) 
Dim hDC As Long 

Dim WindowRect As RECT 
Dim Left As Long 
Dim Top As Long 
Dim Width As Long 
Dim Height As Long 

    If hWnd = 0 Then 
    'Get the DC of the desktop 
    hDC = GetWindowDC(GetDesktopWindow) 

    'Get the virtual screen coordinates (this handles multiple monitors too :) 
    Left = GetSystemMetrics(SM_XVIRTUALSCREEN) 
    Top = GetSystemMetrics(SM_YVIRTUALSCREEN) 
    Width = GetSystemMetrics(SM_CXVIRTUALSCREEN) 
    Height = GetSystemMetrics(SM_CYVIRTUALSCREEN) 

    Else 
    'Get the DC of the window we want to capture 
    hDC = GetWindowDC(hWnd) 

    'Get the window coordinates 
    GetWindowRect hWnd, WindowRect 
    Left = 0 
    Top = 0 
    Width = WindowRect.Right - WindowRect.Left 
    Height = WindowRect.Bottom - WindowRect.Top 

    End If 

    'BitBlt into our own DC 
    BitBlt picScreen.hDC, 0, 0, Width, Height, hDC, Left, Top, vbSrcCopy 

    'Delete our reference to the windows's DC 
    ReleaseDC hWnd, hDC 
End Function 

デスクトップのキャプチャ時には、GetSystemMetrics()を使用していることに注意してください。これにより、just the primary monitorの代わりに複数のモニタが使用されているときに、仮想スクリーン画面の完全な大きさを得ることができます。