Image Lists

[PaulJayKnight]

When I put an image from a file in a PictureBox with SizeMode set to StretchImage I get an effect
that I like. Is there any way to format images from a file before putting them into an ImageList to
get the same effect? these images are being used in objects that don't have a SizeMode.

[Cimperiali]

Yes. For example:
in a form, with a picture, a button and an OpenFileDialog
(the picture sizemode is center, the picture is anchored to all sides)
(so if you load a picture, and trhen resize the form, you will see
how the picture chancge in size and width, and the image is resized
accordingli, but not by the pictureBox, by the code)

Public Class Form1
   Dim ResizeImg As New ResizeImage
   'to do subsequent resiziong on the 
   'original one so not to lose too much details:
   Dim originalImg As Image

   Private Sub btnLoad_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoad.Click
      With OFDGetPicture

         .CheckFileExists = True
         .Filter = "all graphics|*.bmp;*.jpg;*.jpeg;*.gif|bmp|*.bmp|jpg|*.jpg;*.jpeg|gif|*.gif|all files|*.*"
         .Multiselect = False
         .ShowHelp = False
         .ShowReadOnly = False

         If .ShowDialog = Windows.Forms.DialogResult.OK Then

            picFixed.Image = ResizeImg.ResizeImage(.FileName, picFixed.Height, picFixed.Width, originalImg)

         End If

      End With

   End Sub

   Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
      If Me.WindowState <> FormWindowState.Minimized Then
         If picFixed.Image IsNot Nothing Then
           'here: use originalImg, not to lose too much details!)
            picFixed.Image = ResizeImg.ResizeImage(originalImg, picFixed.Height, picFixed.Width)
         End If
      End If
   End Sub
End Class

in a class:

Imports System.IO
Imports System.Drawing

Public Class ResizeImage
   



   Public Function ResizeImage(ByVal OriginalImage As Image _
                               , ByVal NewHeight As Integer _
                               , ByVal NewWidth As Integer _
                               ) As Image

      'the easiest: if you know witdth and height you want
      'and you have the image

      Return OriginalImage.GetThumbnailImage(NewWidth, NewHeight, Nothing, Nothing)



   End Function

   Public Function ResizeImage(ByVal filePathNameOfOriginalImage As String _
                               , ByVal NewHeight As Integer _
                               , ByVal NewWidth As Integer _
                               , ByRef OriginalImage As Image) As Image

      'overload 2: if you know witdth and height you want, and you need 
      'to get image from a file. You return also the original image not to lose
      'too details if resize are asked again: caller should subsequently call the first overload
      'always passing this OriginalImage parm
      OriginalImage = GetImageFromFile(filePathNameOfOriginalImage)
      Return ResizeImage(OriginalImage _
                         , NewHeight, NewWidth)



   End Function

   Private Function GetImageFromFile(ByVal filePathName As String) As Image
      'get an image from a file

      Dim RetVal As Image = Nothing
      If File.Exists(filePathName) Then
         
         RetVal = System.Drawing.Image.FromFile(filePathName)
      End If
      Return RetVal
   End Function


End Class

[PaulJayKnight]

Thank you that worked

[Cimperiali]

By the way, if you play with jpg/jpeg, you might experience a random data loss due to the fact that if a thumbnail is contained inside an image, the getThumbnail will (if it can) get the inside thumb istead of the main Image.
In case, you need to get rid of the internal thumb. A way to do it is to convert the loaded image in a Bmp before.
The zip here contain a sample where that job is done in memory.
Have a look: