winForm checkedListBox使用方法

    public partial class CheckListBoxTest : Form
    {
        public CheckListBoxTest()
        {
            InitializeComponent();
        }

        string connstr = "server=localhost;user id=root;password=****;persistsecurityinfo=True;database=student";
        private void Form1_Load(object sender, EventArgs e)
        {
            using (MySqlConnection conn = new MySqlConnection(connstr))
            {
                MySqlDataAdapter sda = new MySqlDataAdapter("SELECT * FROM dc_commoncourseclass", conn);
                DataTable dt = new DataTable();
                sda.Fill(dt);

                checkedListBox1.DataSource = dt;
                checkedListBox1.ValueMember = "ClassId";
                checkedListBox1.DisplayMember = "ClassName";

                for(int i = 0; i < checkedListBox1.Items.Count;i++)
                {
                    DataRowView dr = checkedListBox1.Items[i] as DataRowView;
                    WriteLine(dr["ClassName"] + "," + dr["ClassId"]);
                    
                    if ((int)dr["ClassId"] == 3)
                    {
                        //两种设置选中值的方法
                        checkedListBox1.SetItemChecked(i, true);
                        checkedListBox1.SetItemCheckState(1, CheckState.Indeterminate);
                    }
                }

                listBox1.SelectionMode = SelectionMode.MultiExtended;
                listBox1.DataSource = dt;
                listBox1.ValueMember = "ClassId";
                listBox1.DisplayMember = "ClassName";

            }

            
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string strText = string.Empty;
            foreach(var o in checkedListBox1.CheckedItems)
            {
                //获取选定项的文本
                strText += checkedListBox1.GetItemText(o) + ",";

                //通过DataRowView获取值
                DataRowView drv = o as DataRowView;
                WriteLine(drv["ClassId"]);
            }
            WriteLine("选择文本：" + strText);

            //通过遍历选中项索引获取选中项的值
            string strValue = string.Empty;
            foreach (int i in checkedListBox1.CheckedIndices)
            {
                checkedListBox1.SetSelected(i, true);
                strValue += checkedListBox1.SelectedValue + ",";
            }
            WriteLine("选择值:" + strValue);
        }

        private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            System.Diagnostics.Process.Start("http://www.baidu.com");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            foreach(var o in listBox1.SelectedItems)
            {
                WriteLine(o);
            }
        }
    }