如何将整个画面暗下来，如同关机前一般_visualbasic教程

PrivateTypeRECT
LeftAsLong
TopAsLong
RightAsLong
BottomAsLong
EndType

PrivateDeclareFunctionGetDCLib”user32″(ByValhwndAsLong)AsLong
PrivateDeclareFunctionReleaseDCLib”user32″(ByValhwndAsLong,ByValhdcAsLong)AsLong
PrivateDeclareFunctionCreatePatternBrushLib”gdi32″(ByValhBitmapAsLong)AsLong
PrivateDeclareFunctionPatBltLib”gdi32″(ByValhdcAsLong,ByValxAsLong,ByValyAsLong,ByValnWidthAsLong,ByValnHeightAsLong,ByValdwRopAsLong)AsLong
PrivateDeclareFunctionDeleteObjectLib”gdi32″(ByValhObjectAsLong)AsLong
PrivateDeclareFunctionCreateBitmapLib”gdi32″(ByValnWidthAsLong,ByValnHeightAsLong,ByValnPlanesAsLong,ByValnBitCountAsLong,lpBitsAsAny)AsLong
PrivateDeclareFunctionSelectObjectLib”gdi32″(ByValhdcAsLong,ByValhObjectAsLong)AsLong
PrivateDeclareFunctionInvalidateRectLib”user32″(ByValhwndAsLong,ByVallpRectAsLong,ByValbEraseAsLong)AsLong

Privatebybits(1To16)AsByte
PrivatehBitmapAsLong,hBrushAsLong
PrivatehDesktopWndAsLong
注释：将图变暗，如同待关机一般
PrivateSubCommand1_Click()
DimropAsLong,resAsLong
Dimhdc5AsLong,width5AsLong,height5AsLong
注释：如果只要让Picture1有效果将底下三行unMark取代hdc5,width5,height5三个值
注释：hdc5=Picture1.hdc
注释：width5=Picture1.ScaleWidth
注释：height5=Picture1.ScaleHeight

注释：底下三行设定整个萤幕都暗下来
hdc5=GetDC(0)
width5=Screen.Width\Screen.TwipsPerPixelX
height5=Screen.Height\Screen.TwipsPerPixelY

rop=&HA000C9注释：与原图做and运算
CallSelectObject(hdc5,hBrush)
res=PatBlt(hdc5,0,0,width5,height5,rop)
CallDeleteObject(hBrush)
注释：如果只暗picture1则底下这一行要mark起来
res=ReleaseDC(0,hdc5)
EndSub
注释：回复原本的画面
PrivateSubCommand2_Click()
DimaaAsLong
注释：如果只暗picture1则底下这一行要unMark起来
注释：Picture1.Refresh

注释：如果只暗picture1则底下这一行要mark起来
aa=InvalidateRect(0,0,1)
EndSub

PrivateSubForm_Load()
Dimary
DimiAsLong
ary=Array(&H55,&H0,&HAA,&H0,_
&H55,&H0,&HAA,&H0,_
&H55,&H0,&HAA,&H0,_
&H55,&H0,&HAA,&H0)
Fori=1To16
bybits(i)=ary(i-1)
Nexti
hBitmap=CreateBitmap(8,8,1,1,bybits(1))
hBrush=CreatePatternBrush(hBitmap)
Picture1.ForeColor=RGB(0,0,0)
Picture1.BackColor=RGB(255,255,255)
Picture1.ScaleMode=3
EndSub->