コンボボックスの自動選択機能について

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Me.ComboBox1.Items.Add("AAAA ああああ")

    End Sub



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Me.ComboBox1.Text = "AAAA"

    End Sub

End Class

初期化
comboBox1.Items.AddRange(new object[] {
				"AAAAA あああああ",
				BBBBB びびびびび",
				"CCCCC ししししし"});

処理
private void button1_Click(object sender, System.EventArgs e)
{
	comboBox1.Text="BBBBB";
}