ASP.NET创建动态缩略图的方法

(编辑:jimmy 日期: 2025/9/18 浏览:2)

本文实例讲述了ASP.NET创建动态缩略图的方法。分享给大家供大家参考。具体分析如下:

提示:

1. 导入 System.IO
2. 创建 类C lass "CreateThumbnails"
or any class and place following function inside that class

You need one function to response call back to main function

Function ImageAbortDummyCallback() As Boolean
Return False
End Function

具体代码如下:

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

希望本文所述对大家的asp.net程序设计有所帮助。

一句话新闻
高通与谷歌联手!首款骁龙PC优化Chrome浏览器发布
高通和谷歌日前宣布,推出首次面向搭载骁龙的Windows PC的优化版Chrome浏览器。
在对骁龙X Elite参考设计的初步测试中,全新的Chrome浏览器在Speedometer 2.1基准测试中实现了显著的性能提升。
预计在2024年年中之前,搭载骁龙X Elite计算平台的PC将面世。该浏览器的提前问世,有助于骁龙PC问世就获得满血表现。
谷歌高级副总裁Hiroshi Lockheimer表示,此次与高通的合作将有助于确保Chrome用户在当前ARM兼容的PC上获得最佳的浏览体验。