ADO (二) 把ADO.NET封装成数据库数据成C#对象

要封装成类我们的先导入命名空间：

using System.Data;
using System.Data.SqlClient;

然后把非查询语句封装：

执行非查询语句
<param name="sql">insert,update,delete语句</param>
<returns>影响的行数</returns>

 public int ExecuteNonQuery(string sql)
        {

            PreparedCommand(sql, null);

            int i = cmd.ExecuteNonQuery();
            Close();
            return i;
        }

执行查询语句

public SqlDataReader ExecuteQuery(string sql)
        {
            PreparedCommand(sql, null);
            return cmd.ExecuteReader();
        }

那我们就试试封装吧：

 using System.Data;
using System.Data.SqlClient;
namespace Com.HS.DBHelper
{
    public class SqlHelper
    {
        private SqlConnection con = null;
        private SqlCommand cmd = null;
        private string connectionString;
        /// <summary>
        /// 获取连接字符串
        /// </summary>
        public string ConnectionString
        {
            get { return this.connectionString; }
        }
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="strcon">连接字符串</param>
        public SqlHelper(string strcon)
        {
            con = new SqlConnection(strcon);
            cmd = new SqlCommand();
            cmd.Connection = con;
            this.connectionString = strcon;
        }
        /// <summary>
        /// 执行非查询语句
        /// </summary>
        /// <param name="sql">insert,update,delete语句</param>
        /// <param name="param">参数</param>
        /// <returns>影响的行数</returns>
        public int ExecuteNonQuery(string sql, params SqlParameter[] param)
        {
            PreparedCommand(sql, param);
            int i = cmd.ExecuteNonQuery();
            Close();
            return i;
        }
        /// <summary>
        /// 执行非查询语句
        /// </summary>
        /// <param name="sql">insert,update,delete语句</param>
        /// <returns>影响的行数</returns>
        public int ExecuteNonQuery(string sql)
        {

            PreparedCommand(sql, null);

            int i = cmd.ExecuteNonQuery();
            Close();
            return i;
        }
        /// <summary>
        /// 执行查询
        /// </summary>
        /// <param name="sql">查询语句</param>
        /// <param name="param">参数</param>
        /// <returns>SqlDataReader</returns>
        public SqlDataReader ExecuteQuery(string sql, params SqlParameter[] param)
        {
            PreparedCommand(sql, param);
            return cmd.ExecuteReader();
        }
        /// <summary>
        /// 执行查询
        /// </summary>
        /// <param name="sql">查询语句</param>
        /// <returns>SqlDataReader</returns>
        public SqlDataReader ExecuteQuery(string sql)
        {
            PreparedCommand(sql, null);
            return cmd.ExecuteReader();
        }
        /*
            用来初始化Command对象
        */
        private void PreparedCommand(string sql, params SqlParameter[] param)
        {
            /*
            SqlCommand cmd1 = null;
            if(cmd!=null)
            {
                cmd1 = cmd;
            }
            else{
                cmd1 = new SqlCommand();
            }*/
            cmd.CommandText = sql;
            //清空Parameters中的参数
            cmd.Parameters.Clear();
            if (param != null)
            {
                foreach (SqlParameter p in param)
                {
                    cmd.Parameters.Add(p);
                }
            }
            con.Open();
        }

        /*
            打开数据库
        */
        private void Open()
        {
            con.Open();
        }
        /*
            关闭数据库
        */
/// <summary>
        /// 关闭数据库

        /// </summary>


        public void Close()
        {

            cmd.Dispose();
            con.Close();
        }

    }
}

嗯我们还可以把存储过程，事物还有DataTable也封装到DBHelper类里，那就再试试封装？...
可能会有点遗漏希望大家多指点...