妳非要用程序的話，看看壹下參考
註意：
PicClipD的ScaleMode=vbPixels
源圖像是ImgSrc
目的圖像是PicDest，註意它的屬性
最關鍵的實現過程在CmdMake_Click
將下列內容復制到記事本，並保存為相應的文件
PicScale.vbp
--------------------
Type=Exe
Form=FrmMain.frm
Reference=*\G{00020430-0000-0000-C000-000000000046}#2.0#0#..\..\..\..\WINDOWS\system32\stdole2.tlb#OLE Automation
Object={F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0; COMDLG32.OCX
IconForm="FrmMain"
Startup="FrmMain"
HelpFile=""
ExeName32="PicScale.exe" "
Command32="" "
Name="PicScale"
HelpContextID="0"
CompatibleMode="0"
MajorVer=1
MinorVer=0
RevisionVer=0
AutoIncrementVer=0
ServerSupportFiles=0
CompilationType=0
OptimizationType=0
FavorPentiumPro(tm)=0
CodeViewDebugInfo=0
NoAliasing=0
BoundsCheck=0
OverflowCheck=0
FlPointCheck=0
FDIVCheck=0
UnroundedFP=0
StartMode=0
Unattended=0
Retained=0
ThreadPerObject=0
MaxNumberOfThreads=1
[MS Transaction Server]
AutoRefresh=1
FrmMain.frm
----------------------------------
VERSION 5.00
Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0"; "COMDLG32.OCX"
Begin VB.Form FrmMain
Caption = "簡單圖像文件縮放"
ClientHeight = 3810
ClientLeft = 165
ClientTop = 855
ClientWidth = 5505
HasDC = 0 'False
LinkTopic = "Form1"
ScaleHeight = 254
ScaleMode = 3 'Pixel
ScaleWidth = 367
StartUpPosition = 3 '窗口缺省
Begin MSComDlg.CommonDialog CDlgFile
Left = 2160
Top = 1320
_ExtentX = 847
_ExtentY = 847
_Version = 393216
End
Begin VB.PictureBox PicClipD
BackColor = &H8000000C&
HasDC = 0 'False
Height = 1695
Left = 2520
ScaleHeight = 109
ScaleMode = 3 'Pixel
ScaleWidth = 117
TabIndex = 8
TabStop = 0 'False
Top = 840
Width = 1815
Begin VB.PictureBox PicDest
AutoRedraw = -1 'True
BackColor = &H00FFFFFF&
BorderStyle = 0 'None
Height = 495
Left = 240
ScaleHeight = 33
ScaleMode = 3 'Pixel
ScaleWidth = 65
TabIndex = 9
TabStop = 0 'False
Top = 360
Width = 975
End
End
Begin VB.PictureBox PicClipS
BackColor = &H8000000C&
HasDC = 0 'False
Height = 1575
Left = 360
ScaleHeight = 101
ScaleMode = 3 'Pixel
ScaleWidth = 101
TabIndex = 7
TabStop = 0 'False
Top = 840
Width = 1575
Begin VB.Image ImgSrc
Height = 855
Left = 240
Top = 240
Width = 855
End
End
Begin VB.PictureBox PicToolBar
Align = 1 'Align Top
HasDC = 0 'False
Height = 495
Left = 0
ScaleHeight = 29
ScaleMode = 3 'Pixel
ScaleWidth = 363
TabIndex = 0
TabStop = 0 'False
Top = 0
Width = 5505
Begin VB.CommandButton CmdReset
Caption = "復位"
Height = 255
Left = 3960
TabIndex = 6
Top = 120
Width = 780
End
Begin VB.CommandButton CmdMake
Caption = "生成"
Height = 255
Left = 3120
TabIndex = 5
Top = 120
Width = 780
End
Begin VB.TextBox TxtHeight
Height = 270
Left = 2280
TabIndex = 4
Text = "Text1"
Top = 120
Width = 750
End
Begin VB.TextBox TxtWidth
Height = 270
Left = 720
TabIndex = 2
Text = "Text1"
Top = 120
Width = 750
End
Begin VB.Label LblHeight
AutoSize = -1 'True
Caption = "Height:"
Height = 180
Left = 1680
TabIndex = 3
Top = 120
Width = 630
End
Begin VB.Label LblWidth
AutoSize = -1 'True
Caption = "&Width:"
Height = 180
Left = 120
TabIndex = 1
Top = 120
Width = 540
End
End
Begin VB.Menu mnuFile
Caption = "文件(&F)"
Begin VB.Menu mnuOpen
Caption = "打開(&O)..."
End
Begin VB.Menu mnuSave
Caption = "保存(&S)..."
End
Begin VB.Menu mnuSep0_0
Caption = "-"
End
Begin VB.Menu mnuExit
Caption = "退出(&X)"
End
End
End
Attribute VB_Name = "FrmMain"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Private Const CtlSpace = 4 '控件之間的距離
Private Sub CmdMake_Click()
Dim nWidth As Long
Dim nHeight As Long
'得到數值
On Error GoTo ErrNum
nWidth = CLng(TxtWidth.Text)
nHeight = CLng(TxtHeight.Text)
On Error GoTo 0
If nWidth < 1 Or nHeight < 1 Then GoTo ErrNum
'改變大小
On Error GoTo ErrSetSize
PicDest.Move 0, 0, nWidth, nHeight
On Error GoTo 0
'取消PictureBox的緩存
Set PicDest.Picture = Nothing
'繪制圖像
PicDest.PaintPicture ImgSrc, 0, 0, PicDest.ScaleWidth, PicDest.ScaleHeight
Exit Sub
ErrNum:
MsgBox "錯誤的數值！", vbCritical
Exit Sub
ErrSetSize:
MsgBox "無法創建這麽大的圖片！", vbCritical
Exit Sub
End Sub
Private Sub CmdReset_Click()
If ImgSrc.Picture.Type = vbPicTypeNone Then '無圖片
TxtWidth.Text = CStr(1)
TxtHeight.Text = CStr(1)
CmdMake.Enabled = False
Else
TxtWidth.Text = CStr(ImgSrc.Width)
TxtHeight.Text = CStr(ImgSrc.Height)
CmdMake.Enabled = True
Call CmdMake_Click
End If
End Sub
Private Sub Form_Load()
'-- 初始化坐標定位
Dim SM_Me As Long
Dim SM_Tbr As Long
Dim nTemp As Long
SM_Me = Me.ScaleMode
SM_Tbr = PicToolBar.ScaleMode
'定位PicToolBar的高度
With PicToolBar
'計算邊框大小
nTemp = Me.ScaleY(.Height, SM_Me, vbPixels) - .ScaleY(.ScaleHeight, SM_Tbr, vbPixels)
'計算PicToolBar應有高度
nTemp = nTemp + .ScaleY(TxtWidth.Height, SM_Tbr, vbPixels)
'設置高度
.Height = Me.ScaleY(nTemp, vbPixels, SM_Me)
End With
'定位PicToolBar內的控件
nTemp = PicToolBar.ScaleHeight
LblWidth.Move CtlSpace, (nTemp - LblWidth.Height) / 2
TxtWidth.Move LblWidth.Left + LblWidth.Width, 0
LblHeight.Move TxtWidth.Left + TxtWidth.Width + CtlSpace, (nTemp - LblWidth.Height) / 2
TxtHeight.Move LblHeight.Left + LblHeight.Width, 0, TxtHeight.Width, TxtWidth.Height
CmdMake.Move TxtHeight.Left + TxtHeight.Width + CtlSpace, 0, CmdMake.Width, TxtWidth.Height
CmdReset.Move CmdMake.Left + CmdMake.Width + CtlSpace, 0, CmdReset.Width, TxtWidth.Height
ImgSrc.Move 0, 0
PicDest.Move 0, 0
'--設置數值
Call CmdReset_Click
With CDlgFile
.CancelError = True
.Flags = cdlOFNOverwritePrompt Or cdlOFNHideReadOnly
.Filter = "Windows位圖(*.bmp)|*.bmp|所有文件(*.*)|*.*"
End With
End Sub
Private Sub Form_Resize()
If Me.WindowState = 1 Then Exit Sub
On Error Resume Next
Dim nTemp As Long
nTemp = PicToolBar.Height
PicClipS.Move 0, nTemp, Me.ScaleWidth / 2, Me.ScaleHeight - nTemp
PicClipD.Move PicClipS.Width, nTemp, Me.ScaleWidth - PicClipS.Width, PicClipS.Height
End Sub
Private Sub mnuExit_Click()
Unload Me
End Sub
Private Sub mnuOpen_Click()
On Error Resume Next
CDlgFile.ShowOpen
If Err.Number Then Exit Sub '點了取消
'打開
Set ImgSrc.Picture = LoadPicture(CDlgFile.FileName)
If Err.Number Then
MsgBox "無法打開文件！", vbCritical
Exit Sub
End If
On Error GoTo 0
Call CmdReset_Click
End Sub
Private Sub mnuSave_Click()
On Error Resume Next
CDlgFile.ShowSave
If Err.Number Then Exit Sub '點了取消
'保存
SavePicture PicDest.Image, CDlgFile.FileName
If Err.Number Then
MsgBox "無法保存圖片！", vbCritical
Exit Sub
End If
On Error GoTo 0
End Sub