Image resize leaving file locked by IIS worker process [Answered]RSS

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  Danny Seager

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  36 Posts

  Image resize leaving file locked by IIS worker process

  Jun 30, 2012 05:38 PM|Danny Seager|LINK

  I have written a procedure to resize jpgs, it works well apart from the fact that it leaves the input file locked by an IIS worker process.

  I'm assuming I need to improve the garbage collection but I can't see what I'm leaving behind. At the moment I have to restart IIS to unlock the file.

  Public Sub ResizeImage(ByVal FileInput As String, _
                        ByVal FileOutput As String, _
                        ByVal MaxSize As Integer, _
                        Optional ByVal ShrinkOnly As Boolean = True,
                        Optional ByVal DeleteInput As Boolean = True)
  
  
          If My.Computer.FileSystem.FileExists(FileInput) = True Then
              Dim isLandscape As Boolean
  
              Dim image As System.Drawing.Image = System.Drawing.Image.FromFile(FileInput)
              Dim srcWidth As Integer = image.Width
              Dim srcHeight As Integer = image.Height
  
              If srcWidth > srcHeight Then
                  isLandscape = True
              Else
                  isLandscape = False
              End If
  
              Dim FileWidth As Integer
              Dim FileHeight As Integer
              Dim ProcessFile As Boolean = True
  
              If (srcWidth <= MaxSize) And (srcHeight <= MaxSize) Then
                  If ShrinkOnly = False Then
                      ProcessFile = True
                  Else
                      ProcessFile = False
                      My.Computer.FileSystem.CopyFile(FileInput, FileOutput)
                  End If
              Else
              End If
  
              If ProcessFile = True Then
                  If isLandscape = True Then
                      FileWidth = MaxSize
                      FileHeight = (srcHeight / srcWidth) * MaxSize
                  Else
                      FileHeight = MaxSize
                      FileWidth = (srcWidth / srcHeight) * MaxSize
                  End If
  
                  Dim tn As New System.Drawing.Bitmap(FileWidth, FileHeight)
  
                  Dim gr As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(tn)
                  gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed
                  gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed
                  gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Default
  
                  Dim rectDestination As New System.Drawing.Rectangle(0, 0, FileWidth, FileHeight)
                  gr.DrawImage(image, rectDestination, 0, 0, srcWidth, srcHeight, System.Drawing.GraphicsUnit.Pixel)
  
                  tn.Save(FileOutput, System.Drawing.Imaging.ImageFormat.Jpeg)
  
                  gr.Dispose()
                  tn.Dispose()
  
                  If DeleteInput = True Then
                      My.Computer.FileSystem.DeleteFile(FileInput)
                  Else
                  End If
              End If
          End If
  
      End Sub

  
  
  

• • Reply
  Imar_Spaanja...

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  488 Posts

  ASPInsiders

  MVP

  Re: Image resize leaving file locked by IIS worker process

  Jul 01, 2012 04:13 AM|Imar_Spaanjaars|LINK

  Hi Danny,

  You're not disposing the image variable. Either call Dispose on it when you're done, or wrap it in a Using statement:

  Using image As System.Drawing.Image = System.Drawing.Image.FromFile(FileInput)
  
    ' Code here
  
  End Using

  
  The latter option is preferred (and is what you should use for your other disposable variables as well) as it ensures proper clean up even when your code crashes.

  Hope this helps,

  Imar

  Imar Spaanjaars - ASP.NET MVP
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