有ListBox.DrawItem事件，为什么ListBox不能选定

Question

我设置的： private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            string s = this.listBox1.Items[e.Index].ToString();
            Brush b;
            switch (s)
            {
                case "成功":
                    b = new SolidBrush(Color.Blue);
                    break;
                case "失败":
                    b = new SolidBrush(Color.Red);
                    break;
                default:
                    b = new SolidBrush(this.ForeColor);
                    break;
            }
            e.Graphics.DrawString(s, this.Font, b, e.Bounds);
        }
为什么listBOx1不能选定项了？

Answer 1

--可以的噢，前台加入一个TextBox(textBox1)和一个ListBox(listBox1),后台代码如下public Form9()
        {
            InitializeComponent();
        }        private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            string s = this.listBox1.Items[e.Index].ToString();
            Brush b;
            switch (s)
            {
                case "成功":
                    b = new SolidBrush(Color.Blue);
                    break;
                case "失败":
                    b = new SolidBrush(Color.Red);
                    break;
                default:
                    b = new SolidBrush(this.ForeColor);
                    break;
            }
            e.Graphics.DrawString(s, this.Font, b, e.Bounds);
        }        private void Form9_Activated(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
            listBox1.Items.AddRange(new Object[] { "成功", "失败", "其他" });
        }        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.textBox1.Text = this.listBox1.SelectedItem.ToString();
        }

Answer 2

也不知道啥原因，我加上一句：e.DrawBackground();
就可以在listBox中选定项了
啥原因？

Answer 3

可以选定，只是没有画出来吧
e.DrawBackground()就是把选定的哪个蓝条画出来，你也可以不使用它，自己画其它颜色