Ytukyg

I hope I get this in the right area, super new here.
I am working on image conversion in windows forms.

My code is:

Imports System.Drawing

Imports System.Drawing.Imaging



Public Class ImageConversion

     Private currentFile As String

     Private image As Image



      Private Sub OpenToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles OpenToolStripMenuItem.Click

        With OpenFile 

            .Title = "Open Image File" 

            .Filter = "Bitmap Files|*.bmp" + 

                "|Enhanced Windows MetaFile|*.emf" + 

                "|Exchangeable Image File|*.exif" + 

                "|Gif Files|*.gif" + 

                "|Icons|*.ico" + 

                "|JPEG Files|*.jpg" + 

                "|PNG Files|*.png" + 

                "|TIFF Files|*.tif" + 

                "|Windows MetaFile|*.wmf"

            .DefaultExt = "jpg" 

            .FilterIndex = 6 

            .FileName = "" 

        End With

        OpenFile.ShowDialog() 

        If OpenFile.FileName = "" Then 

            Return

        End If

        currentFile = OpenFile.FileName.ToString() 

        image = Image.FromFile(OpenFile.FileName) .

        PictureBox1.Image = image

        Me.Text = "Image Conversion -" & OpenFile.SafeFileName.ToString() 

    End Sub



    Private Sub BitmapToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles BitmapToolStripMenuItem.Click

        Dim newName As String = System.IO.Path.GetFileNameWithoutExtension(currentFile)

        newName = newName + ".bmp"

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

            Try

                Image.Save(SaveFile.FileName, ImageFormat.Bmp)

            Catch ex As Exception

                MessageBox.Show("Failed to save image to bitmap.", "Error" & ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Error)

                Return

            End Try

            MessageBox.Show("Image File Saved To" + SaveFile.FileName.ToString(), "Image Saved", MessageBoxButtons.OK, MessageBoxIcon.Information)

        End If

    End Sub

End Class

This is then repeated for each additional file type. Whenever going to convert my file type doesn't change to the desired conversion nor does the save option give me the choice to pick and it actually doesn't save it as anything other than file type: File.

Attached is a snippet of what happens when the save pops up.

I feel like there is something simple I am missing here.

I've modified your original class to add some missing features:

• The selected File Format returned by the SaveFileDialog()
  


• The selection of Filters in SaveFileDialog() is reduced to the formats that Image.Save() actually supports


• 
  IDisposable support, used to dispose of the Bitmap that is currently loaded


• Some others details you can find in the notes and in the class code

This is now a stand-alone class that can be used in other contexts (there's no reference to specific controls or methods:

Sample usage:

Initialize the ImageConversion class (in a Form's constructor or where you think is appropriate):

Public Partial Class Form1

    Public imgConversion As ImageConversion = New ImageConversion()

    '(...)



End Class

Your handlers can be modified like this:

Private Sub OpenToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles OpenToolStripMenuItem.Click



    If PictureBox1.Image IsNot Nothing Then PictureBox1.Image.Dispose()

    Dim NewBitmapFile = imgConversion.OpenFile()

    If NewBitmapFile.OpenedBitmap IsNot Nothing Then

        PictureBox1.Image = NewBitmapFile.OpenedBitmap

        Me.Text = NewBitmapFile.FileName

    End If

End Sub



Private Sub BitmapToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles BitmapToolStripMenuItem.Click

    Dim SavedFile = imgConversion.SaveFileFormat()

    If SavedFile.ErrorMessage <> String.Empty Then

        MessageBox.Show("Failed to save image to Bitmap.", "Error" & SavedFile.ErrorMessage, MessageBoxButtons.OK, MessageBoxIcon.Error)

    ElseIf SavedFile.FileName <> String.Empty Then

        MessageBox.Show("Image File saved to: " + SavedFile.FileName, "Image Saved", MessageBoxButtons.OK, MessageBoxIcon.Information)

    End If

End Sub

Dispose of the ImageConversion class when the Form is closed, this will free the last Image object used:

Private Sub Form1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed

    imgConversion.Dispose()

End Sub

To note:

1. Since you are using a method that returns a Bitmap object and this object is then assigned to a PictureBox.Image property, you need to dispose of the previous Image, if any, before assigning a new one. Otherwise this lost object will linger on more that it's desired and it this will hamper you app.
   




2. The Filters, in the SaveFileDialog, have beed reduced to the ImageFormats that are actually supported by GDI+ when creating a new Bitmap.
   Icon, WMF, EMF and Exif are not supported and the resulting Image will be a PNG file format, the default GDI+ format.
   
   The first three can be created with other means, but this is a broad matter and can't be addressed here.
   



3. 
   

   A couple of methods return a ValueTuple, in the form of ValueTuple(Of T1, T2).
   
   I'm not sure your VB.Net version supports this return type and form.
   
   If not, the method can be modified to return ByRef results or a specialized public object (a sub-class of ImageConversion) that holds the required informations (probably preferable).
   

   
   
   

   Public Function OpenFile() As (OpenedBitmap As Image, FileName As String)
   
   '(...)
   
   Dim result = OpenFile()
   
   Dim img As Bitmap = result.OpenedBitmap 
   
   Dim fName As String = result.FileName
   
   

   
   

The ImageConversion class:

Imports System.Drawing.Imaging

Imports System.Globalization

Imports System.IO



Public Class ImageConversion

    Implements IDisposable



    Private IsDisposed As Boolean = False

    Private CurrentFile As String

    Private CurrentBitmap As Image



    Private Enum FilterType

        OpenFile

        SaveFile

    End Enum



    Public Function OpenFile() As (OpenedBitmap As Image, FileName As String)

        Using OFD As OpenFileDialog = New OpenFileDialog()

            With OFD

                .CheckFileExists = True

                .CheckPathExists = True

                .RestoreDirectory = True

                .Title = "Open Image File"

                .Filter = GetFileFilters(FilterType.OpenFile)

                .FilterIndex = 4

                .FileName = ""

            End With

            If OFD.ShowDialog() = DialogResult.Cancel Then Return Nothing



            CurrentFile = OFD.FileName

            If CurrentBitmap IsNot Nothing Then CurrentBitmap.Dispose()

            CurrentBitmap = CType(Image.FromFile(CurrentFile).Clone(), Bitmap)

        End Using

        Return (CurrentBitmap, CurrentFile)

    End Function



    Public Function SaveFileFormat() As (FileName As String, ErrorMessage As String)

        Dim NewFileName As String = Path.GetFileNameWithoutExtension(CurrentFile)

        Dim ErrorMessage As String = String.Empty

        Using SFD As SaveFileDialog = New SaveFileDialog()

            With SFD

                .AddExtension = True

                .ValidateNames = True

                .CheckPathExists = True

                .RestoreDirectory = True

                .Title = "Save Image File"

                .Filter = GetFileFilters(FilterType.SaveFile)

                .FileName = NewFileName

            End With



            If SFD.ShowDialog() = DialogResult.Cancel Then Return (String.Empty, String.Empty)

            Try

                NewFileName = SFD.FileName

                Dim imgFormat As ImageFormat = GetImageFormat(NewFileName)

                CurrentBitmap.Save(NewFileName, imgFormat)

            Catch ex As IOException

                NewFileName = String.Empty

            End Try

        End Using

        Return (NewFileName, ErrorMessage)

    End Function



    Private Function GetImageFormat(FileName As String) As ImageFormat

        Dim fileType As String = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(Path.GetExtension(FileName).Remove(0, 1).ToLower())

        If fileType = "Tif" Then fileType = "Tiff"

        If fileType = "Jpg" Then fileType = "Jpeg"

        Dim imgFormat As ImageFormat = New ImageFormat(New Guid())

        Return DirectCast(imgFormat.GetType().GetProperty(fileType).GetValue(imgFormat), ImageFormat)



    End Function



    Private Function GetFileFilters(Filter As FilterType) As String

        Dim Filters As String() = {

            "BMP Files|*.bmp", "|GIF Files|*.gif", "|JPEG Files|*.jpg",

            "|PNG Files|*.png", "|TIFF Files|*.tif", "|Enhanced Windows MetaFile|*.emf",

            "|Exchangeable Image File|*.exif", "|Icons|*.ico", "|Windows MetaFile|*.wmf"

        }



        Select Case Filter

            Case FilterType.OpenFile

                Return String.Join("", Filters)

            Case FilterType.SaveFile

                Return String.Join("", Filters.Take(5))

            Case Else

                Return String.Empty

        End Select

    End Function



    Public Sub Dispose() Implements IDisposable.Dispose

        Dispose(True)

        GC.SuppressFinalize(Me)

    End Sub



    Protected Overridable Sub Dispose(disposing As Boolean)

        If IsDisposed Then Return

        If disposing Then

            If CurrentBitmap IsNot Nothing Then

                CurrentBitmap.Dispose()

            End If

        End If

        IsDisposed = True

    End Sub

End Class