AutoCompleteSource停止按键事件?

简单代码C#winform应用程序(visual studio 2010):

带有一个文本框的简单表单是一个按键事件:

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            // The keypressed method uses the KeyChar property to check 
            // whether the ENTER key is pressed. 


            if (e.KeyChar == (char)Keys.Return)
            {
                Process.Start("http://yahoo.com", null);
            }

        }

我需要将文本框更改为autocompletemode=suggestappend和autocompletesource=customsource。然后我把它填成这样:

  private void Form1_Load(object sender, EventArgs e)
        {
            AutoCompleteStringCollection s = new AutoCompleteStringCollection();
            s.Add("Jon ");
            s.Add("2 Jon");
            textBox1.AutoCompleteCustomSource = s;
        }

困惑:)。