关于listBox的郁闷问题 急！ 在线等！！

Question

w我想实现listBox的item左右移动的问题，下面的代码应该是没有问题的，可以一运行就出错误，请大家看看错在哪！  拜托了！！！    protected void Button2_Click(object sender, EventArgs e)
    {
        this.ListBox2.Items.Add(this.ListBox1.SelectedItem.ToString());
       this.ListBox1.Items.Remove(this.ListBox1.SelectedItem.ToString());
        
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        this.ListBox2.Items.Remove(this.ListBox2.SelectedItem.ToString());
        this.ListBox1.Items.Add(this.ListBox2.SelectedItem.ToString());
    }

Answer 1

private void button2_Click(object sender, EventArgs e)
        {
            this.listBox2.Items.Add(this.listBox1.SelectedItem.ToString());
            listBox2.SelectedItem = this.listBox1.SelectedItem;
            this.listBox1.Items.Remove(this.listBox1.SelectedItem.ToString());
            this.listBox1.SelectedIndex = this.listBox1.Items.Count - 1;
            if (listBox1.Items.Count == 0)
            {
                button2.Enabled = false;
                button3.Enabled = true;
            }
            else
            {
                button2.Enabled = true;
                button3.Enabled = false;
            }
        }        private void button3_Click(object sender, EventArgs e)
        {
            this.listBox1.Items.Add(this.listBox2.SelectedItem.ToString());
            listBox1.SelectedItem = this.listBox2.SelectedItem;
            this.listBox2.Items.Remove(this.listBox2.SelectedItem.ToString());
            this.listBox2.SelectedIndex = this.listBox2.Items.Count - 1;
            if (listBox2.Items.Count == 0)
            {
                button2.Enabled = true;
                button3.Enabled = false;
            }
            else
            {
                button2.Enabled = false;
                button3.Enabled = true;
            }
        }