在vb中如何用API函数旋转图片？ vb里面怎么样让一张图片旋转？

没听说过在image中旋转图片的(它连个hdc都没有)，一般都是在picturebox里。具体的api可以用PlgBlt，它是专门实现图像旋转的，不过就是会出现锯齿，但是对你要求的90度，180度和270度就不会出现锯齿。这是我写的旋转函数:Function MyRotation(ByVal DesHdc As Long, ByVal SrcHdc As Long, ByVal DesX As Long, ByVal DesY As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal Angle As Single) As Long
Dim PI As Double
PI = 3.1415926
Dim lpPoint(1 To 3) As POINTAPI
Dim Rad As Double
Rad = Angle * PI / 180
lpPoint(3).x = DesX
lpPoint(3).y = DesX
lpPoint(1).x = lpPoint(3).x + nHeight * Sin(Rad)
lpPoint(1).y = lpPoint(3).y - nHeight * Cos(Rad)
lpPoint(2).x = lpPoint(1).x + nWidth * Cos(Rad)
lpPoint(2).y = lpPoint(1).y + nWidth * Sin(Rad)
PlgBlt DesHdc, lpPoint(1), SrcHdc, 0, 0, nWidth, nHeight, 0, 0, 0
End Function

picturebox就可以，用PLGBIT函数，，，程序如上，回答正确调用方式：MyRotation(目标HDC,源HDC,目标宽度,目标高度,源宽度,源高度,旋转的角度)============================================================================鉴定完毕!

怎么用vb实现图形的旋转？~

启动vb6建立一个标准exe工程，首先添加两个图片框（picture1和picture2），添加三个命令按钮command1（caption=“正常显示”）、command2（caption=“180度倒立”）、command3（caption=“45度旋转”），双击窗体，写入以下代码：
PrivateConstSRCCOPY=&HCC0020
PrivateConstPi=3.14

PrivateDeclareFunctionSetPixelLib"gdi32"(ByValhdcAsLong, ByValxAsLong,ByValyAsLong,ByValcrColorAsLong)AsLong
PrivateDeclareFunctionGetPixelLib"gdi32"(ByValhdcAsLong, ByValxAsLong,ByValyAsLong)AsLong

PrivateDeclareFunctionStretchBltLib"gdi32"(ByValhdcAsLong, ByValxAsLong,ByValyAsLong,ByValnWidthAsLong,ByValnHeightAsLong, ByValhSrcDCAsLong,ByValxSrcAsLong,ByValySrcAsLong,ByValnSrcWidth AsLong,ByValnSrcHeightAsLong,ByValdwRopAsLong)AsLong

privateSubbmp_rotate(pic1AsPictureBox,pic2AsPictureBox,ByValtheta)‘45度旋转
Dimc1xAsInteger,c1yAsInteger
Dimc2xAsInteger,c2yAsInteger
DimaAsSingle
Dimp1xAsInteger,p1yAsInteger
Dimp2xAsInteger,p2yAsInteger
DimnAsInteger,rAsInteger

c1x=pic1.ScaleWidth\2
c1y=pic1.ScaleHeight\2
c2x=pic2.ScaleWidth\2
c2y=pic2.ScaleHeight\2
Ifc2x$#@60;c2yThenn=c2yElsen=c2x
n=n-1
pic1hDC=pic1.hdc
pic2hDC=pic2.hdc
Forp2x=0Ton
Forp2y=0Ton
Ifp2x=0Thena=Pi/2Elsea=Atn(p2y/p2x)
r=Sqr(1&*p2x*p2x+1&*p2y*p2y)
p1x=r*Cos(a+theta)
p1y=r*Sin(a+theta)
c0&=GetPixel(pic1hDC,c1x+p1x,c1y+p1y)
c1&=GetPixel(pic1hDC,c1x-p1x,c1y-p1y)
c2&=GetPixel(pic1hDC,c1x+p1y,c1y-p1x)
c3&=GetPixel(pic1hDC,c1x-p1y,c1y+p1x)
Ifc0&$#@60;$#@62;-1ThenSetPixelpic2hDC,c2x+p2x,c2y+p2y,c0
Ifc1&$#@60;$#@62;-1ThenSetPixelpic2hDC,c2x-p2x,c2y-p2y,c1
Ifc2&$#@60;$#@62;-1ThenSetPi pic2hDC,c2x+p2y,c2y-p2x,c2
Ifc3&$#@60;$#@62;-1ThenSetPixelpic2hDC,c2x-p2y,c2y+p2x,c3
Next
Next
EndSub

PrivateSubCommand1_Click()‘正常复制
Picture2.Cls
px=Picture1.ScaleWidth
py=Picture1.ScaleHeight
StretchBltPicture2.hdc,px,0,-px,py,Picture1.hdc,0,0,px,py,SRCCOPY
EndSub

PrivateSubCommand2_Click()‘180度倒立
Picture2.Cls
px=Picture1.ScaleWidth
py=Picture1.ScaleHeight
StretchBltPicture2.hdc,0,py,px,-py,Picture1.hdc,0,0,px,py,SRCCOPY
EndSub

PrivateSubCommand3_Click()‘45旋转
Picture2.Cls
Callbmp_rotate(Picture1,Picture2,3.14/4)
EndSub

PrivateSubForm_Load()
OnErrorResumeNext
Me.Caption=App.Title"添加应用程序标题
Me.Left=(Screen.Width-Me.Width)/2
Me.Top=(Screen.Height-Me.Height)/2"窗体具中
Picture1.ScaleMode=3
Picture2.ScaleMode=3
EndSub

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