楼主这个问题不大好办，用API吧，主要用到以下API函数 '----------------------------------------------------------------- Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long Declare Function CreateBitmap Lib "gdi32" (ByVal nWidth As Long, ByVal nHeight As Long, ByVal nPlanes As Long, ByVal nBitCount As Long, lpBits As Any) As Long Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long Declare Function CreateBitmapIndirect Lib "gdi32" (lpBitmap As BITMAP) As Long Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long Declare Function GetMapMode Lib "gdi32" (ByVal hdc As Long) As Long Declare Function SetMapMode Lib "gdi32" (ByVal hdc As Long, ByVal nMapMode As Long) As Long Declare Function SetBkColor Lib "gdi32" (ByVal hdc As Long, ByVal crColor As Long) As Long 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 Declare Function StretchBlt Lib "gdi32" (ByVal hdc 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 nSrcWidth As Long, ByVal nSrcHeight As Long, ByVal dwRop As Long) As Long 要代码我可以给你发。
If picMemPhotoBack.Picture <> 0 Then picMemPhoto.PaintPicture picMemPhotoBack.Picture, 0, 0, picMemPhoto.ScaleWidth, picMemPhoto.ScaleHeight, 0, 0 End If picMemPhoto 用来显示 picMemPhotoback 用来存原来的图。不过如果要对图进行保存，要用picMemPhotoback，不然要失真
'-----------------------------------------------------------------
Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long
Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Declare Function CreateBitmap Lib "gdi32" (ByVal nWidth As Long, ByVal nHeight As Long, ByVal nPlanes As Long, ByVal nBitCount As Long, lpBits As Any) As Long
Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Declare Function CreateBitmapIndirect Lib "gdi32" (lpBitmap As BITMAP) As Long
Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long
Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Declare Function GetMapMode Lib "gdi32" (ByVal hdc As Long) As Long
Declare Function SetMapMode Lib "gdi32" (ByVal hdc As Long, ByVal nMapMode As Long) As Long
Declare Function SetBkColor Lib "gdi32" (ByVal hdc As Long, ByVal crColor As Long) As Long
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
Declare Function StretchBlt Lib "gdi32" (ByVal hdc 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 nSrcWidth As Long, ByVal nSrcHeight As Long, ByVal dwRop As Long) As Long
要代码我可以给你发。
picMemPhoto.PaintPicture picMemPhotoBack.Picture, 0, 0, picMemPhoto.ScaleWidth, picMemPhoto.ScaleHeight, 0, 0
End If
picMemPhoto 用来显示
picMemPhotoback 用来存原来的图。不过如果要对图进行保存，要用picMemPhotoback，不然要失真
不过这个问题是很简单的一个缩放。
缩放有两种，一种是按原比例缩放，另一种是按图片框大小缩放，前者不变形，后者很可能会变形（图像被拉长或压扁）关键语句：
Picture.Paintpicture
这个方法可以实现缩放贴图。使用说明如下：object.PaintPicture picture, x1, y1, width1, height1, x2, y2, width2, height2, opcodePaintPicture 方法的语法包含下列部分：部分 描述
object 可选的。一个对象表达式，其值为“应用于”列表中的一个对象。如果省略 object，带有焦点的 Form 对象缺省为 object。
Picture 必需的。要绘制到 object 上的图形源。Form 或 PictureBox 必须是 Picture 属性。
x1, y1 必需的。均为单精度值，指定在 object 上绘制 picture 的目标坐标（x-轴和y-轴）。object 的 ScaleMode 属性决定使用的度量单位。
Width1 可选的。单精度值，指示 picture 的目标宽度。object 的 ScaleMode 属性决定使用的度量单位。如果目标宽度比源宽度 (width2) 大或小，将适当地拉伸或压缩 picture。如果该参数省略，则使用源宽度。
Height1 可选的。 单精度值，指示 picture 的目标高度。object 的 ScaleMode 属性决定使用的度量单位。如果目标高度比源高度 (height2) 大或小，将适当地拉伸或压缩 picture。如果该参数省略，则使用源高度。
x2, y2 可选的。均为单精度值，指示 picture 内剪贴区的坐标（x-轴和y-轴）。object 的 ScaleMode 属性决定使用的度量单位。如果该参数省略，则缺省为 0。
Width2 可选的。单精度值，指示 picture 内剪贴区的源宽度。object 的 ScaleMode 属性决定使用的度量单位。如果该参数省略，则使用整个源宽度。
Height2 可选的。 单精度值，指示 picture 内剪贴区的源高度。object 的 ScaleMode 属性决定使用的度量单位。如果该参数省略，则使用整个源高度。
Opcode 可选的。是长型值或仅由位图使用的代码。它用来定义在将 pictur 绘制到 object 上时对 picture 执行的位操作（例如， vbMergeCopy 或 vbSrcAnd 操作符）。关于位操作符常数的完整列表，请参阅 Visual Basic Help 文件中的 RasterOp Constants 主题。
在使用opcode时有一些限制。例如，如果资源是图标或图元文件，则只能使用 vbSrcCopy，而不能使用其他的opcode；并且，与图案 (或 SDK 术语中的"画笔")，如 MERGECOPY、 PATCOPY、 PATPAINT 和 PATINVERT，相交互的opcode实际上是同目标的 FillStyle 属性交互。注意 Opcode 用于将按位操作传递到位图。当传递其他图象类型时将一个值给该参数会造成“无效过程调用或参数”错误。这是设计的原因。要避免这个错误，对于除位图外的图象，将 Opcode 参数置为空。
说明通过使用负的目标高度值 (height1) 和 / 或目标宽度值 (width1) ，可以水平或垂直翻转位图。 可以省略任何多个可选的尾部的参数 。如果省略了一个或多个可选尾部参数，则不能在指定的最后一个参数后面使用逗号。如果想指定某个可选参数，则必须先指定语法中出现在该参数前面的全部参数。注意，在将一个.Bmp加载入 PictureBox 控件和使用 Windows API 函数 BitBlt() 添加图片之间有一点不同。当您对一个图象使用 BitBlt() 时，PictureBox 控件不知道象您使用 LoadPicture方法那样去调整大小。将 ScaleWidth 和 ScaleHeight 属性设置为图象的大小也不起作用。如果您想在使用 BitBlt 之后用 PictureBox 调整新图片的大小，必须用代码手工做，转换单位并处理边框，下面是如何这样做的一个简单示例：Sub ResizePictureBoxToImage(pic as PictureBox, twipWd _
as Integer, twipHt as Integer)
' 该代码假设所有的单位都为缇。如果
' 不是，必须在调用该例程之前，转换为缇。
' 这里也假设图象显示在0,0处。
Dim BorderHt as Integer, BorderWd as Integer
BorderWd = Pic.Width - Pic.ScaleWidth
BorderHt = Pic.Height - Pic.ScaleHeight
pic.Move pic.Left, pic.Top, twipWd + BorderWd, _
twipHt + BorderHt
End Sub