TextBox showing Line numbers

[Andreas Lohr]

hi,
I would need a TextBox (like RadTextBox), that can show line numbers (similar like in VS).
Best regards
Andreas

P.S.: If that is already possible, please let me know !!

[Martin Vasilev]

Hello Andreas,

Thank you for your question.

RadTextBox does not support adding line numbers. Actually, it internally uses the standard Microsoft TextBox for the textbox part and since the MS textbox does not support this feature, we do not support it as well. If we receive more requests about this feature, we may consider implementing it in one of our future releases.

Let me know if you have any other questions.

Best wishes,
Martin Vasilev
the Telerik team

[Richard Slade]

Hi, 

Even though it doesn't come with it, you can use a mix of a picture box and a standard rich textbox to do this. 
I can't attach a solution here, but follow these steps. 

1: New Windows Forms Project. 
2: Drag on a picture box and dock it to the left
3: Drag on a Rich Text Box and Dock Fill
4: Add the following code to the code behind: 

#Region "TextBox_Resize"
    ''' <summary>
    ''' TextBox_Resize
    ''' </summary>
    ''' <param name="sender">The sender</param>
    ''' <param name="e">The event arguments</param>
    ''' <remarks>Invalidates the lines control</remarks>
    Private Sub TextBox_Resize(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles RichTextBox1.Resize

        PictureBoxLineNumbers.Invalidate()
    End Sub
#End Region

#Region "TextBox1_VScroll"
    ''' <summary>
    ''' TextBox_VScroll
    ''' </summary>
    ''' <param name="sender">The sender</param>
    ''' <param name="e">The event arguments</param>
    ''' <remarks>Invalidates the lines control</remarks>
    Private Sub SqlRichTextBox_VScroll(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles RichTextBox1.VScroll

        PictureBoxLineNumbers.Invalidate()
    End Sub
#End Region


#Region "PictureBoxLines_Paint"
    ''' <summary>
    ''' PictureBoxLines_Paint
    ''' </summary>
    ''' <param name="sender">The sender</param>
    ''' <param name="e">The event arguments</param>
    ''' <remarks>On Pain, draws the line umbers</remarks>
    Private Sub PictureBoxLines_Paint(ByVal sender As System.Object, _
        ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBoxLineNumbers.Paint

        DrawRichTextBoxLineNumbers(e.Graphics)
    End Sub
#End Region

#Region "DrawRichTextBoxLineNumbers"
    ''' <summary>
    ''' DrawRichTextBoxLineNumbers
    ''' </summary>
    ''' <param name="g">The graphics parameter</param>
    ''' <remarks>Draws teh line numbers on the picture box</remarks>
    Private Sub DrawRichTextBoxLineNumbers(ByVal g As System.Drawing.Graphics)
        If True Then
            Dim font_height As Single = 0

            font_height = _
            RichTextBox1.GetPositionFromCharIndex(RichTextBox1.GetFirstCharIndexFromLine(2)).Y - _
            RichTextBox1.GetPositionFromCharIndex(RichTextBox1.GetFirstCharIndexFromLine(1)).Y
            If font_height = 0 Then
                font_height = 13
            End If

            'Get the first line index and location
            Dim first_index As Integer = 0
            Dim first_line As Integer = 0
            Dim first_line_y As Integer = 0
            first_index = RichTextBox1.GetCharIndexFromPosition(New Point(0, Convert.ToInt32(g.VisibleClipBounds.Y + font_height / 3, CultureInfo.InvariantCulture)))
            first_line = RichTextBox1.GetLineFromCharIndex(first_index)
            first_line_y = RichTextBox1.GetPositionFromCharIndex(first_index).Y

            'Print on the PictureBox the visible line numbers of the RichTextBox
            g.Clear(Control.DefaultBackColor)
            Dim i As Integer = first_line
            Dim y As Single = 0
            While y < g.VisibleClipBounds.Y + g.VisibleClipBounds.Height
                y = first_line_y + 2 + font_height * (i - first_line - 1)
                Dim s2 As Single = PictureBoxLineNumbers.Width - g.MeasureString((i).ToString(CultureInfo.InvariantCulture), RichTextBox1.Font).Width
                If i > 0 Then
                    g.DrawString(i.ToString(CultureInfo.InvariantCulture), RichTextBox1.Font, Brushes.Black, s2, y)
                End If
                i += 1
            End While
        End If
    End Sub
#End Region