代码如下：

以下为引用的内容：   'Form1.frm   VERSION 5.00   Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0"; "COMDLG32.OCX"   Begin VB.Form Form1   Caption = "Form1"   ClientHeight = 5010   ClientLeft = 60   ClientTop = 345   ClientWidth = 7800   LinkTopic = "Form1"   ScaleHeight = 334   ScaleMode = 3 'Pixel   ScaleWidth = 520   StartUpPosition = 3 '窗口缺省   Begin MSComDlg.CommonDialog CommonDialog1   Left = 4635   Top = 3120   _ExtentX = 847   _ExtentY = 847   _Version = 393216   End   Begin VB.Frame Frame1   Caption = "Frame1"   Height = 3000   Left = 4500   TabIndex = 2   Top = 30   Width = 3180   Begin VB.PictureBox Picture2   Appearance = 0 'Flat   ForeColor = &H80000008&   Height = 2625   Left = 120   ScaleHeight = 173   ScaleMode = 3 'Pixel   ScaleWidth = 194   TabIndex = 3   Top = 255   Width = 2940   Begin VB.Image Image1   Height = 1575   Left = 465   Top = 390   Width = 1965   End   End   End   Begin VB.CommandButton Command1   Caption = "&Load Picture"   Height = 330   Left = 5400   TabIndex = 0   Top = 3150   Width = 1425   End   Begin VB.PictureBox Picture1   Appearance = 0 'Flat   AutoSize = -1 'True   BorderStyle = 0 'None   ForeColor = &H80000008&   Height = 4425   Left = 60   ScaleHeight = 4425   ScaleWidth = 4380   TabIndex = 1   Top = 105   Width = 4380   End   End   Attribute VB_Name = "Form1"   Attribute VB_GlobalNameSpace = False   Attribute VB_Creatable = False   Attribute VB_PredeclaredId = True   Attribute VB_Exposed = False   Option Explicit      Dim ReturnHeight As Long, ReturnWidth As Long      Private Sub Command1_Click()   Dim BigWidth As Long, BigHeight As Long   Dim StretchWidth As Long, StretchHeight As Long   CommonDialog1.Filter = "jpeg文件|*.jpg|gif文件|*.gif|所有文件|*.*"   CommonDialog1.ShowOpen   If CommonDialog1.FileName <> "" Then   Picture1.Picture = LoadPicture(CommonDialog1.FileName)      BigWidth = Picture1.Width   BigHeight = Picture1.Height   StretchWidth = Picture2.ScaleWidth   StretchHeight = Picture2.ScaleHeight      StretchImage BigWidth, BigHeight, StretchWidth, StretchHeight, True      Image1.Stretch = True   Image1.Width = ReturnWidth   Image1.Height = ReturnHeight      Image1.Left = (Picture2.ScaleWidth - Image1.Width) / 2   Image1.Top = (Picture2.ScaleHeight - Image1.Height) / 2   Image1.Picture = LoadPicture(CommonDialog1.FileName)   End If   End Sub      Private Sub StretchImage(OriginalWidth As Long, OriginalHeight As Long, StretchWidth As Long, StretchHeight As Long, Optional Flag As Boolean = False)   If (OriginalWidth >= StretchWidth Or OriginalHeight > StretchHeight) Or Flag = True Then '需要缩放   If OriginalWidth / OriginalHeight >= StretchWidth / StretchHeight Then   ReturnWidth = StretchWidth   ReturnHeight = StretchWidth / OriginalWidth * OriginalHeight   Else   ReturnHeight = StretchHeight   ReturnWidth = StretchHeight / OriginalHeight * OriginalWidth   End If   Else   ReturnHeight = OriginalHeight   ReturnWidth = OriginalWidth   End If   End Sub