GdipSaveImageToFile 函数的图片质量无法控制

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Quality���Ҵ�1���õ�100��ͼƬ������Զ���ܵ͡�

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Public Sub SaveJPG(ByVal pict As Long, ByVal filename As String, Optional
ByVal quality As Byte = 100)
Dim tSI As GdiplusStartupInput
Dim lRes As Long
Dim lGDIP As Long
Dim lBitmap As Long

Dim myQuality As Byte
myQuality = 100

' Initialize GDI+
tSI.GdiplusVersion = 1
lRes = GdiplusStartup(lGDIP, tSI)

If lRes = 0 Then

' Create the GDI+ bitmap
' from the image handle
lRes = GdipCreateBitmapFromHBITMAP(pict, 0, lBitmap)

If lRes = 0 Then
Dim tJpgEncoder As GUID
Dim tParams As EncoderParameters

' Initialize the encoder GUID
CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}"), _
tJpgEncoder

'CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}"),
_
' tJpgEncoder

' Initialize the encoder parameters
tParams.Count = 1
With tParams.Parameter ' Quality
' Set the Quality GUID
CLSIDFromString StrPtr("{1D5BE4B5-FA4A-452D-9CDD-5DB3505E7EB}"),
.GUID
.NumberOfValues = 1
.Type = 4
.Value = VarPtr(myQuality)
End With

' Save the image
lRes = GdipSaveImageToFile(lBitmap, StrPtr(filename), tJpgEncoder,
tParams)

' Destroy the bitmap
GdipDisposeImage lBitmap

End If

' Shutdown GDI+
GdiplusShutdown lGDIP

End If

End Sub

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Private Declare Sub CopyMemory Lib "KERNEL32" Alias "RtlMoveMemory" (lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

Dim aEncParams() As Byte

��End With���֮������2�䣺

ReDim aEncParams(1 To Len(tParams))
Call CopyMemory(aEncParams(1), tParams, Len(tParams))

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GdipSaveImageToFile lBitmap, StrPtr(Filename), tJpgEncoder, aEncParams(1)

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hi,
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