利用FormsAuthentication 类的HashPasswordForStoringInConfigFile 方法实现用户登录口令加密
1、创建password类
using System.Web.Security;引用加密类所在的命明空间
下段代码为加密码过程
public class jmpassword
{
    public string EncryptPassword(string PasswordString,string PasswordFormat )
     {
        string EncryptPassword="";
        if (PasswordFormat=="SHA1")
         {
             EncryptPassword=FormsAuthentication.HashPasswordForStoringInConfigFile(PasswordString ,"SHA1");
             return EncryptPassword;
         } else if (PasswordFormat=="MD5")
                 {
                   EncryptPassword=FormsAuthentication.HashPasswordForStoringInConfigFile(PasswordString ,"MD5");
                   return EncryptPassword;
                 }
                else
                 {
　                  EncryptPassword="";
                    return EncryptPassword;
                 } 　
         }
}
2、在表单中引用类,并将密码框输入的值进行加密
jmpassword Password=new jmpassword();
string password=Password.EncryptPassword(txtpassword.Text.ToString(),"SHA1")+Password.EncryptPassword(txtpassword.Text.ToString(),"MD5");