Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms

Public Class MyRichTextBox2
    Inherits System.Windows.Forms.RichTextBox


    Property MaxLines_Warning As String = ""
    Property MaxLines_Warning_Label As Label = Nothing
    Property MaxLineLength As Integer = -1


    Private Sub MyTextBox_Leave(sender As Object, e As EventArgs) Handles Me.Leave
        If MaxLineLength > 0 Then
            Dim str() As String = Me.Lines
            For i = 0 To Me.Lines.Count - 1
                If str(i).Length > MaxLineLength Then
                    str(i) = str(i).Substring(0, MaxLineLength)
                End If
            Next
            Me.Lines = str
        End If
    End Sub

    Private Sub MyTextBox_Textchanged(sender As Object, e As EventArgs) Handles Me.TextChanged
        'sender.ForeColor = System.Drawing.Color.Black

        If Me.Multiline And IsNumeric(MaxLines_Warning) Then
            ' If Me.Lines.Length > MaxLines Then
            If MaxLines_Warning_Label IsNot Nothing Then
                MaxLines_Warning_Label.Visible = CBool(Me.Lines.Length > MaxLines_Warning)
            End If
            'End If
        End If

    End Sub



End Class