求助,包都导入,书写没错,为什么SqlConnection等下面还是有红色波浪线提示错误?!

Question

包都导入,书写没错,为什么SqlConnection等下面还是有红色波浪线提示错误?!
using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;namespace WebApplication1
{   public static creatConn()
    {return new SqlConnection("server=.;database=ADO.NET;uid=sa;pwd=;");
    public class personcaozuo
    {
    }
    public static bool findPerson(string pID)
    {SqlConnection conn=personcanzuo.creatConn();
     conn.Open();
     SqlCommand comm=new SqlCommand("select count(*) from person WHERE perID='"+pID+"'",conn);
    int count=Covert.ToInt32(comm.ExecuteScalar());
    if(count>0)
    {return true;}
    else
    {return false;}
    public static bool insertPerson(person p)
    {SqlConnection conn=personcanzuo.creatConn();
     conn.Open();
     SqlCommand comm=new SqlCommand("insert into person values('"+pID+"','"+pName+"')",conn);
     comm.ExecuteNonQuery();
     conn.Close();
     return true;
}

Answer 1

同上 没有返回值 public static  creatConn() 

Answer 2

public static SqlConnection creatConn()我加了返回类型SqlConnection了,
但是还是在SqlConnection和DataTable   SqlDateAdapter  SqlCommand等ADO的这些常用组件上打了提示错误的红色波浪线

Answer 3

方法应该写在类里，结束的括号也不匹配namespace WebApplication1 
{
    public class personcaozuo
    {
        public static void creatConn()
        {
            return new SqlConnection("server=.;database=ADO.NET;uid=sa;pwd=;");
        }        public static bool findPerson(string pID)
        {
            SqlConnection conn = personcanzuo.creatConn();
            conn.Open();
            SqlCommand comm = new SqlCommand("select count(*) from person WHERE perID='" + pID + "'", conn);
            int count = Covert.ToInt32(comm.ExecuteScalar());
            if (count > 0)
                return true;            return false;
        }
        public static bool insertPerson(person p)
        {
            SqlConnection conn = personcanzuo.creatConn();
            conn.Open();
            SqlCommand comm = new SqlCommand("insert into person values('" + pID + "','" + pName + "')", conn);
            comm.ExecuteNonQuery();
            conn.Close();
            return true;
        }
    }
}