一个同学让帮忙写作业，MD5加密的登陆。

就用到一个 System.Security.Cryptography;

用jquery加了一个浮动层，身份验证没用ajax。

源码下载

部分代码：

using System;
using System.Web;
using System.Web.Security;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;//数据库操作
using System.Security.Cryptography;//MD5
using System.Data;
using System.Configuration;

/// <summary>
///DB 的摘要说明
/// </summary>
public class DB
{
	public DB()
	{
	}

    /// <summary>
    /// 连接数据库
    /// </summary>
    /// <returns>返回SqlConnection对象</returns>
    public SqlConnection GetCon()
    {
        return new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
    }

    /// <summary>
    /// 执行SQL语句
    /// </summary>
    /// <param name="cmdstr">SQL语句</param>
    /// <returns>成功1，失败0</returns>
    public int SqlEx(string cmdstr)
    {
        SqlConnection con = GetCon();
        con.Open();
        SqlCommand cmd = new SqlCommand(cmdstr,con);
        try
        {
            cmd.ExecuteNonQuery();
            return 1;
        }
        catch (Exception e)
        {
            return 0;
        }
        finally
        {
            con.Dispose();
        }
    }

    /// <summary>
    /// 执行SQL查询语句
    /// </summary>
    /// <param name="cmdstr">SQL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">SQL查询语句</param>
    /// <returns>返回SqlDataReader对象dr</returns>
    public SqlDataReader reDr(string str)
    {
        SqlConnection conn = GetCon();
        conn.Open();
        SqlCommand com=new SqlCommand(str,conn);
        SqlDataReader dr = com.ExecuteReader(CommandBehavior.CloseConnection);
        return dr;
    }

    public string MD5(string strPwd)
    {
        MD5 md5 = new MD5CryptoServiceProvider();
        //将字符编码为一个字节序列
        byte[] data = System.Text.Encoding.Default.GetBytes(strPwd);
        //计算data字节数组的哈希值
        byte[] md5data = md5.ComputeHash(data);
        md5.Clear();
        string str = string.Empty;
        for (int i = 0; i < md5data.Length-1; i++)
        {
            str += md5data[i].ToString("x").PadLeft(2,'0');
        }
        return str;
    }
}

转载请注明：于哲的博客 » Asp.Net（2）：MD5加密登陆模块