C# 怎样点击一个按钮时将label的Text内容显示到listBox1的Items中？

Question

如题所述

Answer 1

        private void button1_Click(object sender, EventArgs e)
        {
            string s = this.label1.Text;
            if (this.listBox1.Items.Contains(s))
                MessageBox.Show("不能重复添加！");
            else
                this.listBox1.Items.Add(s);
        }