using System;
using System.Configuration;
using System.Data;
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.Text;
using System.Security.Cryptography;//MD5加密需引入的命名空间
using System.Data.SqlClient;//数据库操作需引入的命名空间

/// <summary>
/// DB 的摘要说明
/// </summary>
public class DB
{
?public DB()
?{
??//
??// TODO: 在此处添加构造函数逻辑
??//
?}

??? /// <summary>
??? /// 连接数据库
??? /// </summary>
??? /// <returns>返回SqlConnection对象</returns>
??? public SqlConnection GetCon()
??? {

//该处要在web.config中配置一个

<configuration>
? <appSettings>
??? <add key="ConnectionString" value="Database='test';Data Source='localhost';User Id='root';Password='root';charset='utf8'"/>
? </appSettings>

?

??????? return new SqlConnection(ConfigurationManager.AppSettings["ConnectionString"].ToString());
??? }

??? /// <summary>
??? /// 执行SQL语句
??? /// </summary>
??? ///<param name="cmdstr">SQL语句</param>
??? /// <returns>返回值为int型：成功返1，失败返回0</returns>
??? public int sqlEx(string cmdstr)
??? {
??????? SqlConnection con = GetCon();//连接数据库
??????? con.Open();//打开连接
??????? SqlCommand cmd = new SqlCommand(cmdstr, con);
??????? try
??????? {
??????????? cmd.ExecuteNonQuery();//执行SQL 语句并返回受影响的行数
??????????? return 1;//成功返回１
??????? }
??????? catch (Exception e)
??????? {
??????????? return 0;//失败返回０
??????? }
??????? finally
??????? {
??????????? con.Dispose();//释放连接对象资源
??????? }
??? }
???
??? /// <summary>
??? /// 执行SQL查询语句
??? /// </summary>
??? /// <param name="cmdstr">查询语句</param>
??? /// <returns>返回DataTable数据表</returns>
??? public DataTable reDt(string cmdstr)
??? {
??????? SqlConnection con =GetCon();
??????? SqlDataAdapter da = new SqlDataAdapter(cmdstr, con);
??????? DataSet ds = new DataSet();
??????? da.Fill(ds);
??????? return (ds.Tables[0]);
??? }
??? /// <summary>
??? /// 执行SQL查询语句
??? /// </summary>
??? /// <param name="str">查询语句</param>
??? /// <returns>返回SqlDataReader对象dr</returns>
??? public SqlDataReader reDr(string str)
??? {
??????? SqlConnection conn = GetCon();//连接数据库
??????? conn.Open();//并打开了连接
??????? SqlCommand com = new SqlCommand(str, conn);
??????? SqlDataReader dr = com.ExecuteReader(CommandBehavior.CloseConnection);
??????? return dr;//返回SqlDataReader对象dr
??? }
??? /// <summary>
??? /// MD5加密
??? /// </summary>
??? /// <param name="strPwd">被加密的字符串</param>
??? /// <returns>返回加密后的字符串</returns>
??? public string GetMD5(string strPwd)
??? {
??????? string pwd = "";
??????? //实例化一个md5对象
??????? MD5 md5 = MD5.Create();
??????? // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择
??????? byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(strPwd));
??????? //翻转生成的MD5码???????
??????? s.Reverse();???
??????? //通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
??????? //只取MD5码的一部分，这样恶意访问者无法知道取的是哪几位
??????? for (int i = 3; i < s.Length - 1; i++)
??????? {
??????????? //将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符
??????????? //进一步对生成的MD5码做一些改造
??????????? pwd = pwd + (s[i] < 198 ? s[i] + 28 : s[i]).ToString("X");
??????? }
??????? return pwd;
??? }
}