ASP.NET Image uploading with Resizing

Question

I have an aspx page which will upload images to server harddisk from client pc

But now i need to change my program in such a way that it would allow me to resize the

Answer 1

You will not be able to resize "on the fly" since you will need to have the full image before you perform any image transformations. However, after the upload is complete and before you display any results to your user, you can use this basic image resizing method that I've used in a couple of my apps now:

   ''' 

   '''    Resize image with GDI+ so that image is nice and clear with required size.
   ''' 
   ''' Image to resize
   ''' New height to resize to.
   ''' New width to resize to.
   ''' Image object resized to new dimensions.
   ''' 
   Public Shared Function ImageResize(ByVal SourceImage As Image, ByVal NewHeight As Int32, ByVal NewWidth As Int32) As Image

      Dim bitmap As System.Drawing.Bitmap = New System.Drawing.Bitmap(NewWidth, NewHeight, SourceImage.PixelFormat)

      If bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Format1bppIndexed Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Format4bppIndexed Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Format8bppIndexed Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Undefined Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.DontCare Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Format16bppArgb1555 Or _
          bitmap.PixelFormat = Drawing.Imaging.PixelFormat.Format16bppGrayScale Then
         Throw New NotSupportedException("Pixel format of the image is not supported.")
      End If

      Dim graphicsImage As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bitmap)

      graphicsImage.SmoothingMode = Drawing.Drawing2D.SmoothingMode.HighQuality
      graphicsImage.InterpolationMode = Drawing.Drawing2D.InterpolationMode.HighQualityBicubic
      graphicsImage.DrawImage(SourceImage, 0, 0, bitmap.Width, bitmap.Height)
      graphicsImage.Dispose()
      Return bitmap

   End Function