Public Class Form1
Private urc As New UndoRedoClass(Of String)()
Private NoAdd As Boolean = False
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Button_Undo.Enabled = False
Button_Redo.Enabled = False
urc.AddItem(RichTextBox1.Text)
End Sub
Private Sub Button_Undo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Undo.Click
NoAdd = True
urc.Undo()
RichTextBox1.Text = urc.CurrentItem
Button_Undo.Enabled = urc.CanUndo
Button_Redo.Enabled = urc.CanRedo
NoAdd = False
End Sub
Private Sub Button_Redo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Redo.Click
NoAdd = True
urc.Redo()
RichTextBox1.Text = urc.CurrentItem
Button_Undo.Enabled = urc.CanUndo
Button_Redo.Enabled = urc.CanRedo
NoAdd = False
End Sub
Private Sub RichTextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles RichTextBox1.TextChanged
If Not NoAdd Then
urc.AddItem(RichTextBox1.Text)
Button_Undo.Enabled = urc.CanUndo
Button_Redo.Enabled = urc.CanRedo
End If
End Sub
End Class