CSharp动态添加Combox项的几种方法

namespace AAFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("Display");
            dt.Columns.Add("Value");
            for (int i = 0; i < 5; i++)
            {
                DataRow dr = dt.NewRow();
                dr["Display"] = "显示" + i.ToString();
                dr["Value"] = i;
                dt.Rows.Add(dr);
            }
            comboBox1.DataSource = dt;
            comboBox1.DisplayMember = "Display";
            comboBox1.ValueMember = "Value";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            List<KeyValuePair<int, string>> cbList = new List<KeyValuePair<int, string>>();
            Dictionary<int, string> dic = new Dictionary<int, string>();
            cbList.Add(new KeyValuePair<int, string>(1, "my"));
            cbList.Add(new KeyValuePair<int, string>(2, "is"));
            cbList.Add(new KeyValuePair<int, string>(3, "hero"));

            for (int i = 0; i < 5; i++)
            {
                dic.Add(i, i.ToString());
            }
            comboBox1.DataSource = cbList;
            //comboBox1.DataSource = dic; //不能是字典，这里添加会失败
            comboBox1.DisplayMember = "Value";
            comboBox1.ValueMember = "Key";
        }

        private void button3_Click(object sender, EventArgs e)
        {
            string[] daysOfWeek =  { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" };
            comboBox1.DataSource = daysOfWeek;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            //如果要一个一个的添加，前面不能指定DataSource，否则失败
            string[] daysOfWeek = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" };
            foreach (var d in daysOfWeek)
            {
                comboBox1.Items.Add(d);
            }
            //或者//comboBox1.Items.AddRange(daysOfWeek);
        }

        private void button5_Click(object sender, EventArgs e)
        {
            //如果要一个一个的添加，前面不能指定DataSource，否则失败
            comboBox1.Items.Insert(0, new ComboBoxItem("0", "请选择"));
            comboBox1.Items.Insert(1, new ComboBoxItem("1", "根目录"));
        }
    }

    internal class ComboBoxItem : Object
    {
        private string _value;
        private string _text;
        public ComboBoxItem(string v, string t)
        {
            _value = v;
            _text = t;
        }
        public string Text
        {
            get { return _text; }
        }
        public string Value
        {
            get { return _value; }
        }
        public override string ToString()
        {
            return _text;
        }

    }
}