自我学习之一：淡入淡出（抄）

Option Explicit

Public Sub IntervalX(ByVal intI As Integer)
If intI > 0 Then Sleep (intI) '制造千分之intI秒的时间间隔
End Sub

Public Sub ShowTransparency(SrcDC As Long, _
ByVal SrcX As Long, _
ByVal SrcY As Long, _
ByVal SrcHeight As Long, _
ByVal SrcWidth As Long, _
DestDC As Long, _
ByVal DestX, _
ByVal DestY, _
ByVal DestHeight As Long, _
ByVal DestWidth As Long, _
ByVal nLevel As Byte)

Dim LrProps As rBlendProps
Dim LnBlendPtr As Long

LrProps.tBlendAmount = nLevel
CopyMemory LnBlendPtr, LrProps, 4
AlphaBlend DestDC, DestX, DestY, DestWidth, DestHeight, _
SrcDC, SrcX, SrcY, SrcWidth, SrcHeight, LnBlendPtr
End Sub

Public Sub CopyPictureX(ByVal dcSour As Long, _
ByVal SourX As Long, _
ByVal SourY As Long, _
ByVal dcDest As Long, _
ByVal DestX As Long, _
ByVal DestY As Long, _
ByVal DestWidth As Long, _
ByVal DestHeight As Long)
'dcSour——>dcDest

BitBlt dcDest, DestX, DestY, DestWidth, DestHeight, dcSour, SourX, SourY, SRCCOPY

End Sub

Public Sub ScreenCls()

'刷新桌面
InvalidateRectAsAny 0, ByVal 0&, True

End Sub

Private Sub Form_Load()

Dim i, l, t

Picture2.Height = Picture1.Height
Picture2.Width = Picture1.Width

l = (Screen.Width / Screen.TwipsPerPixelX - Picture1.ScaleWidth) / 2
t = (Screen.Height / Screen.TwipsPerPixelY - Picture1.ScaleHeight) / 2

CopyPictureX GetDC(0), l, t, Picture2.hdc, 0, 0, Picture2.ScaleWidth, Picture2.Height

For i = 0 To 150 Step 7
IntervalX 150 - i
DoEvents
ShowTransparency Picture1.hdc, 0, 0, Picture1.ScaleHeight, _
Picture1.ScaleWidth, GetDC(0), l, t, _
Picture1.ScaleHeight, Picture1.ScaleWidth, i
Next i

IntervalX 1000

For i = 0 To 150 Step 7
IntervalX 150 - i
DoEvents
ShowTransparency Picture2.hdc, 0, 0, Picture2.ScaleHeight, _
Picture2.ScaleWidth, GetDC(0), l, t, _
Picture2.ScaleHeight, Picture2.ScaleWidth, i
Next i

ScreenCls

Unload Me

End Sub