1.把数据绑定到CheckBoxList中

  protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                SqlConnection con = GetDBCon.GetCon();
                con.Open();
                SqlDataAdapter sda = new SqlDataAdapter("select * from admin", con);
                DataSet ds = new DataSet();
                sda.Fill(ds,"admin");
                this.CheckBoxList1.DataSource = ds.Tables[0];
                this.CheckBoxList1.DataTextField = "username";//绑定的字段名
                this.CheckBoxList1.DataValueField = "userid";//绑定的值
                this.CheckBoxList1.DataBind();
              
            
               
            }
        } 

2.循环读取出来

 protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.Lab2.Text = "";
            for (int i = 0; i < CheckBoxList1.Items.Count; i++)
            {
                if (this.CheckBoxList1.Items[i].Selected)
                {
                    this.Lab2.Text = this.Lab2.Text+CheckBoxList1.Items[i].Text+".";
                }
            }
        }

#endregion

样式设置：

RepeatColumns="3" 列数
RepeatLayout="Table" table布局方式
RepeatDirection="Horizontal"
或
RepeatDirection="Vertical"