百叶窗效果

　　 
　　百叶窗效果

　　实现步骤：

　　1．建立一个新项目，将其命名为Demo5.vbp。

　　2．增加模块Demo5.bas，在Demo5.bas中加入如下代码：

Public Const SRCCOPY = &HCC0020

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

　
　　3．在窗体的声明部分加入代码：

　　Dim h, w As Integer

　　4．在窗体的Form_Load处理程序中加入代码：

Private Sub Form_Load()
Picture1.Move 0, 0
Picture2.Move 0, 0
h = Picture1.ScaleHeight
w = Picture1.ScaleWidth
Picture2.Width = Picture1.Width
Picture2.Height = Picture1.Height
End Sub

　　5．在窗体的Command1_Click处理代码中：

Private Sub Command1_Click()
Dim i, j, g As Integer
Picture2.Cls
For i = 0 To 50
For j = i To w Step 50
BitBlt Picture2.hDC, j, 0, 1, h, Picture1.hDC, j, 0, SRCCOPY
For g = 0 To 500
Next g
Next j
Next i
End Sub

　　6．在窗体的Command2_Click的处理程序中：

Private Sub Command2_Click()
Dim i, j, g As Integer
Picture2.Cls
For i = 0 To 50
For j = i To w Step 50
BitBlt Picture2.hDC, 0, j, w, 1, Picture1.hDC, 0, j, SRCCOPY
For g = 0 To 500
Next g
Next j
Next i
End Sub

　　7．在窗体的Picture1_Resize的处理程序中加入代码：

Private Sub Picture1_Resize()
Picture2.Width = Picture1.Width
Picture2.Height = Picture1.Height
End Sub

原文转自：http://www.ltesting.net