public static SqlConnection createConnection() 
 { 
   SqlConnection con = new SqlConnection("server=.;database=dropDownTest;uid=sa;pwd=123456"); 
   con.Open(); 
   return con; 
 } 

public static DataTable SelectAll() 
{ 
  SqlConnection con = createConnection(); 
  DataTable dt = new DataTable(); 
  SqlCommand cmd = new SqlCommand("select * from person", con); 
  SqlDataReader sdr = cmd.ExecuteReader(); 
  dt.Load(sdr); 
  return dt; 
} 

protected void Button4_Click(object sender, EventArgs e) 
{ 
  string c = "";  //定义空字符串，用来条件查询 
   
   //设置复选框1的查询条件 
  if (this.CheckBox1.Checked) 
  { 
    c = "pID=" + this.txtID.Text;  //精确匹配查询条件 
  } 
  else 
  { 
    c = "pID like'%' ";    //模糊匹配查询条件 
  } 
  if (this.CheckBox2.Checked) 
  { 
    c += " and personName like '%" + this.txtName.Text + "%'"; 
  } 
  if (this.CheckBox3.Checked) 
  { 
    if (RadioButton1.Checked) 
    { 
      c += "and personSex='男'"; 
    } 
 
    else 
    { 
      c += "and personSex='女'"; 
    } 
  } 
 
  DataView dv = new DataView(PerosonOperate.SelectAll()); //调用查询方法 
  dv.RowFilter = c;                    //设置过滤器（按条件查找） 
  dv.Sort = "pID Desc";                  //使结果按照pID字段降序排列 
  GridView1.DataSource = dv;               //设定数据源 
  GridView1.DataBind();                  //绑定数据源 
  //设置列名，如果不设置，将会以数据库中对应的字段名称代替 
  GridView1.HeaderRow.Cells[0].Text = "编号"; 
  GridView1.HeaderRow.Cells[1].Text = "姓名"; 
  GridView1.HeaderRow.Cells[2].Text = "性别";