Free Programming Tutorials & Source Code

This example demonstrates how to convert BMP files to other image types. it uses the IO and Drawing library.
First, create a new form, switch to View Code mode, and inset these namespaces at the top of your document:

 Imports System.Drawing.Imaging
 Imports System.IO.Path 

Switch back to the View Design mode, and add the following controls:
TextBox, name it as txtOriginal.
Button, name is as btnOpen
Butoon, name is as btnConvert
ListBox, name is as lbox
OpenFileDialog, name it as file

Add these items to the lbox ListBox:
Emf
Exif
Gif
Icon
MemoryBmp
Png
Tiff
Wmf

Add two labels as shown in the picture below.



Back to the View Code mode, add the following code:

    Public Function ConvertImage(ByVal path As String, _
     ByVal format As ImageFormat) As Boolean

        Dim flag As Boolean
        Dim nFile As String

        Try
            ' create Bitmap variable to hold the old image
            Dim vImage As New Bitmap(path)

            ' set new file directory name
            nFile = GetDirectoryName(path)
            'parse the file name without the extension 
            nFile &= "\" & GetFileNameWithoutExtension(path)
            'add new extension to file
            nFile &= "." & format.ToString
            ' save the file
            vImage.Save(nFile, format)

            flag = True
        Catch ex As Exception
            MsgBox(ex.Message)

            flag = False
        End Try
        Return flag

    End Function
  

btnOpen Click Event:

Private Sub btnOpen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOpen.Click
 file.ShowDialog()
End Sub
 

File FileOk Event:

Private Sub file_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles file.FileOk
 Me.txtOriginal.Text = file.FileName
End Sub

btnConvert Click Event:

     Private Sub btnConvert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvert.Click
        Try
            Select Case Me.lbox.SelectedItem
                Case "Emf"
                    ConvertImage(Me.txtOriginal.Text, ImageFormat.Emf)
                Case "Exif"
                    ConvertImage(txtOriginal.Text, ImageFormat.Exif)
                Case "Gif"
                    ConvertImage(txtOriginal.Text, ImageFormat.Gif)
                Case "Jpeg"
                    ConvertImage(txtOriginal.Text, ImageFormat.Jpeg)
                Case "Icon"
                    ConvertImage(txtOriginal.Text, ImageFormat.Icon)
                Case "MemoryBmp"
                    ConvertImage(txtOriginal.Text, ImageFormat.MemoryBmp)
                Case "Png"
                    ConvertImage(txtOriginal.Text, ImageFormat.Png)
                Case "Tiff"
                    ConvertImage(txtOriginal.Text, ImageFormat.Tiff)
                Case "Wmf"
                    ConvertImage(txtOriginal.Text, ImageFormat.Wmf)
            End Select
        Catch ex As Exception
            MsgBox(ex.Message)
            Exit Sub
        End Try
        MsgBox("Image successfully converted")
    End Sub

Happy coding!