******************************************************************
* 刷新 PictureBox 控件的 Picture 对象。对PictureBox中的任何绘图操作，
* 通过它即可转换为Picture对象
* 使用该函数可将PictureBox内的图象编辑结果永久更新为 Picture 对象
* 参数∶ PicBox PictureBox控件名
*lWidth 需要更新的图象宽度(按你的需要，不局限于目前Picture对
* 象的实际大小)，也是最后要形成的Picture对象的图象宽度(单位∶像素)
*lHeight 需要更新的图象高度，其他类同与 lWidth(单位∶像素)
******************************************************************

Function UpdatePicture(ByRef PicBox As Object, Optional ByVal lWidth As Long = -1, _
Optional ByVal lHeight As Long = -1) As Boolean

On Error GoTo errHandle

Dim oldScMode As Integer
Dim hNewDC As Long
Dim hOldBit As Long
Dim hNewBit As Long

oldScMode = -1
oldScMode = PicBox.ScaleMode
If lWidth = -1 Then
lWidth = PicBox.ScaleX(PicBox.Picture.Width, 8, vbPixels)
End If
If lHeight = -1 Then
lHeight = PicBox.ScaleY(PicBox.Picture.Height, 8, vbPixels)
End If

hNewDC = CreateCompatibleDC(PicBox.hdc)
hNewBit = CreateCompatibleBitmap(PicBox.hdc, lWidth, lHeight)
hOldBit = SelectObject(hNewDC, hNewBit)

BitBlt hNewDC, 0, 0, lWidth, lHeight, PicBox.hdc, 0, 0, vbSrcCopy
SelectObject hNewDC, hOldBit

PicBox.Picture = BitmapToPicture(hNewBit)

DeleteObject hNewDC
DeleteDC hNewDC
If oldScMode <> -1 Then PicBox.ScaleMode = oldScMode
UpdatePicture = True

Exit Function
errHandle:
UpdatePicture = False
If oldScMode <> -1 Then PicBox.ScaleMode = oldScMode
End Function
有关的API函数声明

Option Explicit

Public Const hNull = 0

Public Type IID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(0 To 7) As Byte
End Type

Public Type PICTDESC
cbSizeofstruct As Long
picType As Long
hgdiobj As Long
hPalOrXYExt As Long
End Type

Public Declare Sub OleCreatePictureIndirect Lib "olepro32.dll" ( _
lpPictDesc As PICTDESC, _
riid As IID, _
ByVal fPictureOwnsHandle As Long, _
ipic As IPicture)
Public Declare Function CreateCompatibleDC& Lib "gdi32" (ByVal hdc As Long)
Public Declare Function CreateCompatibleBitmap& Lib "gdi32" ( _
ByVal hdc As Long, _
ByVal nWidth As Long, _
ByVal nHeight As Long)
Public Declare Function DeleteDC& Lib "gdi32" (ByVal hdc As Long)
Public Declare Function SelectObject& Lib "gdi32" ( _
ByVal hdc As Long, _
ByVal hObject As Long)
Public Declare Function DeleteObject& Lib "gdi32" (ByVal hObject As Long)