Public Class frmTestvb

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If CntrlExistsIn("btnEntity2", Panel1) = True Then
            MsgBox("Control2 existiert")
        End If
        Dim btn As New Button
        btn.Name = "btnEntity2"
        btn.Text = "Button 2"
        btn.Size = New Size(160, 45)
        btn.FlatStyle = FlatStyle.Flat
        btn.BackColor = Color.Goldenrod
        btn.FlatAppearance.BorderColor = Color.Gold
        Panel1.Controls.Add(btn)
        btn.Location = New Point(177, 12)
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        If CntrlExistsIn("btnEntity1", Panel1) = True Then
            MsgBox("Control1 existiert")
        End If
        Dim btn As New Button
        btn.Name = "btnEntity1"
        btn.Text = "Button 1"
        btn.Size = New Size(160, 45)
        btn.FlatStyle = FlatStyle.Flat
        btn.BackColor = Color.DeepSkyBlue
        btn.FlatAppearance.BorderColor = Color.LightSkyBlue
        Panel1.Controls.Add(btn)

        btn.Location = New Point(6, 12)
    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        If CntrlExistsIn("btnEntity3", Panel1) = True Then
            MsgBox("Control3 existiert")
        End If
        Dim btn As New Button
        btn.Name = "btnEntity3"
        btn.Text = "Button 3"
        btn.Size = New Size(160, 45)
        btn.FlatStyle = FlatStyle.Flat
        btn.BackColor = Color.DarkViolet
        btn.FlatAppearance.BorderColor = Color.Plum
        Panel1.Controls.Add(btn)
        btn.Location = New Point(348, 12)
    End Sub
    Function CntrlExistsIn(ctrlName As String, parent As Control) As Boolean
        Dim bResult As Boolean = False

        For Each elem As Control In parent.Controls
            If elem.Name = ctrlName Then
                bResult = True
                Exit For
            End If
        Next

        Return bResult
    End Function
End Class