本范例是以一個stdPicture物件來存圖形,之後於PictureBox中以特殊效果來顯示。
因為我們想顯示的只有一個圖,所以不想多用另一個PictureBox來存原始圖,而後 再畫到另一個PictureBox上,那只有用StdPicture物件來取代PictureBox(存來源圖) ,但是BitBlt這個繪圖函式需來源與目的的hDc,而StdPicture物件沒有hDc,它只有一個Handle值,以本例來說,這Handle值便是圖形的hBitmap值。所以我們只好使用MemoryDC的方式來做,產生一個MemoryDc後將BitMap圖放於其上,之後便可以使用BitBlt來繪圖了。
需求一個PictureBox( Named picture2),一個Command按鍵)
Option Explicit 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 CreateCompatibleDC Lib "gdi32" _ (ByVal hdc As Long) As Long Private Declare Function SelectObject Lib "gdi32" _ (ByVal hdc As Long, ByVal hObject As Long) As Long Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long Const SRCCOPY = &HCC0020 Private Picture1 As New StdPicture Private Sub Command1_Click() Dim i As Long Dim j As Long Dim height5 As Long, width5 As Long Dim hMemDc As Long stdPicture物件的度量單位是Himetric所以要轉換成Pixel height5 = ScaleY(Picture1.Height, vbHimetric, vbPixels) If height5 $#@62; Picture2.ScaleHeight Then height5 = Picture2.ScaleHeight End If width5 = ScaleX(Picture1.Width, vbHimetric, vbPixels) If width5 $#@62; Picture2.ScaleWidth Then width5 = Picture2.ScaleWidth End If Create Memory DC hMemDc = CreateCompatibleDC(Picture2.hdc) 將Picture1的BitMap圖指定給hMemDc Call SelectObject(hMemDc, Picture1.Handle) For i = height5 To 1 Step -1 Call BitBlt(Picture2.hdc, 0, i, width5, 1, _ hMemDc, 0, i, SRCCOPY) For j = i - 1 To Step -1 Call BitBlt(Picture2.hdc, 0, j, width5, 1, _ hMemDc, 0, i, SRCCOPY) Next j Next Call DeleteDC(hMemDc) End Sub Private Sub Form_Load() Dim i As Long Picture2.ScaleMode = 3 設定成Pixel的度量單位 設定待Display的圖 Set Picture1 = LoadPicture("c:windows素還真.bmp") ^^^^^^^^^^^^^^^^^^^^^^ Load the picture we want to show End Sub