CheckedListBox的用法：

private System.Windows.Forms.CheckedListBox checkedListBox1;

1.添加选项
checkedListBox1.Items.Add(“选项1”);
checkedListBox1.Items.Add(“选项2”);
checkedListBox1.Items.Add(“选项3”);

2.得到选项个数
int i = checkedListBox1.Items.Count;//所有选项个数
int j = checkedListBox1.CheckedItems.Count;//选中选项个数

3.设置选项选中状态
//第一个参数对应选项索引，第二个参数为选中状态
checkedListBox1.SetItemChecked(0, true);
checkedListBox1.SetItemCheckState(1, CheckState.Checked);

4.得到选项选中状态
//参数为选项索引
bool isChecked0 = checkedListBox1.GetItemChecked(0);
CheckState checkState1 = checkedListBox1.GetItemCheckState(1);

测试代码：

    private void Form1_Load(object sender, EventArgs e){checkedListBox1.Items.Add("选项1");checkedListBox1.Items.Add("选项2");checkedListBox1.Items.Add("选项3");//第一个参数对应选项索引，第二个参数为选中状态checkedListBox1.SetItemChecked(0, true);checkedListBox1.SetItemCheckState(1, CheckState.Checked);//参数为选项索引bool isChecked0 = checkedListBox1.GetItemChecked(0);CheckState checkState1 = checkedListBox1.GetItemCheckState(1);bool isChecked2 = checkedListBox1.GetItemChecked(2);int i = checkedListBox1.Items.Count;//所有选项个数int j = checkedListBox1.CheckedItems.Count;//选中选项个数label1.Text=isChecked0 + " " + checkState1 + " " +isChecked2+" " + i + " " + j;}

运行结果：

参考：http://blog.csdn.net/cdz1022/article/details/7583291