[讨论]改变图片文件的大小

kevindeng

我想在ＡＣＣＥＳＳ中实现用一个按钮选择一个图片文件(jpg)改变大小后ＣＯＰＹ到另外一个文件夹中，不知道各位有什么好的办法实现吗？

zyp

更改圖片原始尺寸嗎?原800*600,處理成640*480????如果是怎樣,用access那可能是選錯了工具

kevindeng

是的。我是想用VBA代码实现

appleking

这个没人能作吗?
在vb里实现的方式在ACC里为什么不行.
'保存JPEG用

Private Type GUID
   Data1 As Long
   Data2 As Integer
   Data3 As Integer
   Data4(0 To 7) As Byte
End Type

Private Type GdiplusStartupInput
   GdiplusVersion As Long
   DebugEventCallback As Long
   SuppressBackgroundThread As Long
   SuppressExternalCodecs As Long
End Type

Private Type EncoderParameter
   GUID As GUID
   NumberOfValues As Long
   type As Long
   Value As Long
End Type

Private Type EncoderParameters
   Count As Long
   Parameter As EncoderParameter
End Type

Private Declare Function GdiplusStartup Lib "GDIPlus" (token As Long, _
   inputbuf As GdiplusStartupInput, Optional ByVal outputbuf As Long = 0) As Long

Private Declare Function GdiplusShutdown Lib "GDIPlus" (ByVal token As Long) As Long

Private Declare Function GdipCreateBitmapFromHBITMAP Lib "GDIPlus" ( _
   ByVal hbm As Long, ByVal hpal As Long, Bitmap As Long) As Long

Private Declare Function GdipDisposeImage Lib "GDIPlus" (ByVal Image As Long) As Long

Private Declare Function GdipSaveImageToFile Lib "GDIPlus" ( _
   ByVal Image As Long, ByVal filename As Long, _
   clsidEncoder As GUID, encoderParams As Any) As Long

Private Declare Function CLSIDFromString Lib "ole32" (ByVal str As Long, id As GUID) As Long

Public Sub SaveJPG(ByVal pict As StdPicture, ByVal filename As String, _
           Optional ByVal quality As Byte = 80)
   Dim tSI As GdiplusStartupInput
   Dim lRes As Long
   Dim lGDIP As Long
   Dim lBitmap As Long

   ' 初始化 GDI+
   tSI.GdiplusVersion = 1
   lRes = GdiplusStartup(lGDIP, tSI)
   
   If lRes = 0 Then
   
      ' 从句柄创建 GDI+ 图像
      lRes = GdipCreateBitmapFromHBITMAP(pict.Handle, 0, lBitmap)
   
      If lRes = 0 Then
         Dim tJpgEncoder As GUID
         Dim tParams As EncoderParameters
         
         '初始化解码器的GUID标识
         CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}"), _
                         tJpgEncoder
      
         ' 设置解码器参数
         tParams.Count = 1
         With tParams.Parameter ' Quality
            ' 得到Quality参数的GUID标识
            CLSIDFromString StrPtr("{1D5BE4B5-FA4A-452D-9CDD-5DB35105E7EB}"), .GUID
            .NumberOfValues = 1
            .type = 4
            .Value = VarPtr(quality)
         End With
         
         '保存图像
         lRes = GdipSaveImageToFile( _
                  lBitmap, _
                  StrPtr(filename), _
                  tJpgEncoder, _
                  tParams)
                             
         ' 销毁GDI+图像
         GdipDisposeImage lBitmap
         
      End If
      
      '销毁 GDI+
      GdiplusShutdown lGDIP

   End If
   
   If lRes Then
      Err.Raise 5, , "不能保存这个图像：" & lRes
   End If
   
End Sub


Private Sub Command1_Click()
SaveJPG Image1.Picture, sfile, SPA
End Sub
提示是 Image1.Picture 类型不匹配 怎么回事