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.net 里可以轻松对图片文件进行质量压缩(VB) |
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本文由中国C#技术学习中心整理 如果你对本文有不明之处请到技术论坛讨论!
'***********************************************************
'即时预览保存图片质量
'wgscd ( c ) 2005 QQ 153964481,Email: wgscd@126.com
Dim PulicImageCodecInfo As ImageCodecInfo '定义全局变量提高效率
Dim myImageCodecInfo As System.Drawing.Imaging.ImageCodecInfo
Dim myEncoder As System.Drawing.Imaging.Encoder = System.Drawing.Imaging.Encoder.Quality
Dim myEncoderParameter As System.Drawing.Imaging.EncoderParameter
Dim myEncoderParameters As System.Drawing.Imaging.EncoderParameters
Private Sub Form1_Load( ByVal sender As System.Object, ByVal e As System.EventArgs ) Handles MyBase.Load
Me.Text = "保存文件"
Me.Label2.Text = "即时预览保存图片质量
wgscd ( c ) 02005
利用ImageCodecInfo,System.Drawing.Imaging.Encoder"
Me.HScrollBar1.Cursor = Cursors.Hand
PulicImageCodecInfo = GetEncoderInfo( "image/jpeg" ) '获取ImageCodecInfo
Me.PictureBox2.Image.Save( "c:wgscd.jpg" )
Me.PictureBox3.Image = Image.FromFile( "c:wgscd.jpg" )
Dim fi As New FileInfo( "c:wgscd.jpg" )
fi = New FileInfo( "c:wgscd.jpg" )
Label1.Text = HScrollBar1.Value & "大小:" & ( fi.Length / 1024 ).ToString( "0.00" ) & "KB"
Me.PictureBox3.Refresh( ) '必须释放
Me.PictureBox3.Image.Dispose( )
Me.PictureBox3.Image = Me.PictureBox2.Image
End Sub
Private Sub HScrollBar1_Scroll( ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs ) Handles HScrollBar1.Scroll
' Dim MyMemoryStream As IO.MemoryStream = New IO.MemoryStream
myImageCodecInfo = PulicImageCodecInfo '用全局保存的ImageCodecInfo来设置
myEncoderParameters = New System.Drawing.Imaging.EncoderParameters( 1 )
' myEncoderParameter = New System.Drawing.Imaging.EncoderParameter( myEncoder, EncoderValue.TransformRotate90 )
myEncoderParameter = New System.Drawing.Imaging.EncoderParameter( myEncoder, CLng( Me.HScrollBar1.Value ) )
myEncoderParameters.Param( 0 ) = myEncoderParameter
' Me.PictureBox2.Save( MyMemoryStream, myImageCodecInfo, myEncoderParameters )‘ 写如内存流
Try
Me.PictureBox2.Image.Save( "c:wgscd.jpg", myImageCodecInfo, myEncoderParameters )
Me.PictureBox3.Image = Image.FromFile( "c:wgscd.jpg" )
Dim fi As New FileInfo( "c:wgscd.jpg" )
fi = New FileInfo( "c:wgscd.jpg" )
Label1.Text = " 保存质量: " & HScrollBar1.Value & " % 大小:" & ( fi.Length / 1024 ).ToString( "0.00" ) & "KB"
Me.PictureBox3.Refresh( ) '必须释放
Me.PictureBox3.Image.Dispose( )
' myEncoderParameters.Dispose( )
' MyMemoryStream.Flush( )
Catch ex As Exception
'如果有必要处理错误,可加代码
' MsgBox( ex.ToString )
End Try
End Sub '
Private Sub Button2_Click( ByVal sender As System.Object, ByVal e As System.EventArgs ) Handles Button2.Click
Me.Close( )
End Sub
'可以获得系统的ImageEncoders
Sub GetImageEncoders( )
Dim i As Integer
Dim encoders As System.Drawing.Imaging.ImageCodecInfo( ) = Imaging.ImageCodecInfo.GetImageEncoders
For i = 0 To ( encoders.Length - 1 )
MsgBox( encoders( i ).MimeType )
Next i
End Sub
Private Function GetEncoderInfo( ByVal MYmimeType As String ) As ImageCodecInfo
Dim i As Integer
Dim encoders As System.Drawing.Imaging.ImageCodecInfo( ) = Imaging.ImageCodecInfo.GetImageEncoders( )
For i = 0 To ( encoders.Length - 1 )
If ( encoders( i ).MimeType = MYmimeType ) Then
'
MsgBox( encoders( i ).MimeType )
Return encoders( i )
End If
Next i
End Function
本文由中国C#技术学习中心整理 如果你对本文有不明之处请到技术论坛讨论!
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