Convertir Image en base64 et base64 en image

 Voici comment convertir une image en base 64 et en base 64 en image.

il faudra ajouter dans le form1 :

un picturebox et un richtextbox et 3 boutons.

richtextbox à était remplacer par TxtBase64.

ma classe :

Public Class Form1

    Dim codecs As ImageCodecInfo() = ImageCodecInfo.GetImageEncoders()
    Public Function ConvertImageToBase64(ByVal file As Image) As String
        Using memoryStream As MemoryStream = New MemoryStream()
            file.Save(memoryStream, file.RawFormat)
            Dim imageBytes As Byte() = memoryStream.ToArray()
            Return Convert.ToBase64String(imageBytes)
        End Using
    End Function

    Public Function ConvertBase64ToImage(ByVal base64String As String) As Image
        Dim imageBytes As Byte() = Convert.FromBase64String(base64String)
        Using ms As MemoryStream = New MemoryStream(imageBytes, 0, imageBytes.Length)
            ms.Write(imageBytes, 0, imageBytes.Length)
            Return Image.FromStream(ms, True)
        End Using
    End Function

    Private Sub TxtBase64_MouseUp(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles TxtBase64.MouseUp
        If e.Button = System.Windows.Forms.MouseButtons.Right Then
            Dim contextMenu As New ContextMenuStrip
            Dim Item1 As New ToolStripMenuItem("Select All")
            Item1.Image = My.Resources.Apply
            AddHandler Item1.Click, New EventHandler(AddressOf ALLAction)
            contextMenu.Items.Add(Item1)
            contextMenu.Items.Add(New ToolStripSeparator)
            Dim Item2 As New ToolStripMenuItem("Copier")
            Item2.Image = My.Resources.Copy
            AddHandler Item2.Click, New EventHandler(AddressOf CopyAction)
            contextMenu.Items.Add(Item2)
            contextMenu.Items.Add(New ToolStripSeparator)
            Dim Item3 As New ToolStripMenuItem("Coller")
            Item3.Image = My.Resources.Paste
            AddHandler Item3.Click, New EventHandler(AddressOf PasteAction)
            contextMenu.Items.Add(Item3)
            contextMenu.Items.Add(New ToolStripSeparator)
            Dim Item4 As New ToolStripMenuItem("Effacer")
            Item4.Image = My.Resources.clear1
            AddHandler Item4.Click, New eventhandler(AddressOf ClearAction)
            contextMenu.Items.Add(Item4)
            TxtBase64.ContextMenuStrip = contextMenu
        End If
    End Sub

    Private Sub ALLAction()
        If TxtBase64.Text IsNot Nothing AndAlso TxtBase64.TextLength > 0 Then
            TxtBase64.SelectAll()
        End If
    End Sub

    Private Sub CopyAction()
        If TxtBase64.SelectedText IsNot Nothing AndAlso TxtBase64.SelectedText <> "" Then
            Clipboard.SetText(TxtBase64.SelectedText)
            MsgBox("Le code base64 à bien était copier !", MsgBoxStyle.Information, "Copier")
        End If
    End Sub

    Private Sub PasteAction()
        If Clipboard.ContainsText() Then
            Dim selstart As Integer = TxtBase64.SelectionStart
            If TxtBase64.Text IsNot Nothing AndAlso TxtBase64.Text <> "" Then
                TxtBase64.Text = TxtBase64.Text.Remove(selstart, TxtBase64.SelectionLength)
            End If
            Dim clip As String = Clipboard.GetText(TextDataFormat.Text).ToString()
            TxtBase64.Text = TxtBase64.Text.Insert(selstart, clip)
            TxtBase64.SelectionStart = selstart + clip.Length
        End If
    End Sub

    Private Sub ClearAction()
        If TxtBase64.Text IsNot Nothing AndAlso TxtBase64.Text <> "" Then
            TxtBase64.Clear()
        End If
    End Sub

    Private Sub GlowButton1_Click(sender As System.Object, e As System.EventArgs) Handles GlowButton1.Click
        Dim open As New OpenFileDialog With {
             .RestoreDirectory = True,
             .SupportMultiDottedExtensions = False,
             .Title = "Veuillez selectionner une image !",
             .Multiselect = False,
             .CheckFileExists = True,
             .Filter = String.Format("{0}| All image files ({1})|{1}|All files|*", String.Join("|", codecs.[Select](Function(codec) CStr(String.Format("{0} ({1})|{1}", codec.CodecName, codec.FilenameExtension))).ToArray()), String.Join(";", codecs.[Select](Function(codec) codec.FilenameExtension).ToArray()))}
        If open.ShowDialog = Windows.Forms.DialogResult.OK Then
            Dim bmp As New Bitmap(open.FileName)
            If Not IsNothing(PictureBox1.BackgroundImage) Then PictureBox1.BackgroundImage.Dispose()
            PictureBox1.BackgroundImage = bmp
            PictureBox1.BackgroundImageLayout = ImageLayout.Stretch
        Else : Exit Sub
        End If
    End Sub

    Private Sub GlowButton2_Click(sender As System.Object, e As System.EventArgs) Handles GlowButton2.Click
        If PictureBox1.BackgroundImage IsNot Nothing Then
            Using image As Image = TryCast(PictureBox1.BackgroundImage.Clone(), Image)
                TxtBase64.Clear()
                TxtBase64.Text = ConvertImageToBase64(image)
            End Using
        End If
    End Sub

    Private Sub GlowButton3_Click(sender As System.Object, e As System.EventArgs) Handles GlowButton3.Click
        If TxtBase64.TextLength > 0 Then
            PictureBox1.BackgroundImage = ConvertBase64ToImage(TxtBase64.Text)
            PictureBox1.BackgroundImageLayout = ImageLayout.Stretch
        End If
    End Sub
End Class