Código
Public Class Form1 Dim Caracteres(1000) As String Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim i, j, k As Integer Dim Combinacion As String Dim Existe As Boolean For i = 0 To TextBox1.Text.Length - 1 Caracteres(i) = TextBox1.Text.Substring(i, 1) Next For i = 0 To TextBox1.Text.Length - 1 For j = 0 To TextBox1.Text.Length - 1 Existe = False Combinacion = TextBox1.Text.Remove(i, 1) Combinacion = Combinacion.Insert(i, Caracteres(j)) Combinacion = Combinacion.Remove(j, 1) Combinacion = Combinacion.Insert(j, Caracteres(i)) For k = 0 To ListBox1.Items.Count - 1 If Combinacion = ListBox1.Items(k) Then Existe = True Next If Existe = False Then ListBox1.Items.Add(Combinacion) Next Next End Sub End Class