ASP.NET创建动态缩略图的方法_实用技巧_

 Function CreateJPEGThumbnail(ByVal inSourceFile As String, ByVal inDestinationFile As String, ByVal ThumbWidth As Integer, ByVal ThumbHeight As Integer) As Boolean Dim imageFile As System.Drawing.Image Dim outputFstream As New FileStream(inSourceFile, FileMode.Open, FileAccess.Read) 'Exposes a System.IO.Stream around a file, supporting both synchronous and asynchronous read and write operations. Dim ImageAbortCallBack As System.Drawing.Image.GetThumbnailImageAbort 'This method returns true if it decides that the System.Drawing.Image.GetThumbnailImage method should prematurely stop execution; otherwise, it returns false. imageFile = System.Drawing.Image.FromStream(outputFstream) ImageAbortCallBack = New System.Drawing.Image.GetThumbnailImageAbort(AddressOf ImageAbortDummyCallback) imageFile = imageFile.GetThumbnailImage(ThumbWidth, ThumbHeight, ImageAbortCallBack, IntPtr.Zero) 'IntPtr = A platform-specific type that is used to represent a pointer or a handle. imageFile.Save(inDestinationFile, System.Drawing.Imaging.ImageFormat.Jpeg) outputFstream.Close() outputFstream = Nothing imageFile = Nothing End Function