asp.net 利用特性和正则表达式进行字段的验证（attribute）

1.创建自定义的特性类（继承Attribute类）。

　 coding as below

    [AttributeUsage(AttributeTargets.Property,AllowMultiple=false,Inherited=false)]
    public class FileVerification:Attribute
    {
        private string _regexStr;
        public string RegexStr
        {
            get { return _regexStr; }
            set { _regexStr = value; }
        }
        private string _showMessage;
        public string ShowMessage
        {
            get { return _showMessage; }
            set { _showMessage = value; }           
        }
    } 

2.在实体类属性上加上特性：

　 coding as below

    public class Account
    {
        private string _user;
        private string _password;

        [FileVerification(RegexStr = @"^\w{1,50}$", ShowMessage = "请输入账号！")]
        public string User
        {
            get { return _user; }
            set { _user = value; }
        }
        [FileVerification(RegexStr = @"^\w{1,50}$", ShowMessage = "请输入密码！")]
        public string Password
        {
            get { return _password; }
            set { _password = value; }
        }
    }

3.利用正则表达式对属性的值进行验证通用类：

 　　coding as below

　　public class FieldVerification<T>
    　{
       　　 public static string Verification(T t)
       　　 {
           　　 string returenMessage = "";
           　　 string fieldValue = "";
           　　 FileVerification fv = null;
           　　 Type customerType = typeof(T);
           　　 PropertyInfo[] pIList = customerType.GetProperties();
           　　 for (int i = 0; i < pIList.Length; i++)
            　　{
               　　 object[] oList = pIList[i].GetCustomAttributes(typeof(FileVerification), true);
              　　  foreach (object o in oList)
               　　 {
                  　　  fv = (FileVerification)o;
                  　　  fieldValue = Convert.ToString(pIList[i].GetValue(t, null));
                 　　   if (!Regex.IsMatch(fieldValue, fv.RegexStr))
                 　　   {
                  　　      returenMessage += fv.ShowMessage;
                　　    }
               　　 }

            　　}
　　            return returenMessage;
     　　   }
    　}

4.调用验证类：

coding as below

            Account a = new Account();
            a.User = "";
            a.Password = "";
            errorMessage = FieldVerification<Account>.Verification(a);