[练习]利用Attribute对实体进行验证

早上看到了利用特性(Attribute)对实体类进行验证 这篇文章，碰上刚好最近对Attribute有点兴趣，所以对作者写的利用特性(Attribute)对实体类进行验证这篇文章进行练习并且对知识点进行巩固。

自己改写的版本如下：C#4.0

C#2.0代码using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Reflection;

public partial class Darren_testValidate : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
string msg = string.Empty;
User user = new User();
user.Password = TextBox1.Text.Trim();

if (ValidateHelper.GetValidateResult(user, out msg))
{
Response.Write("测试通过");
//Console.WriteLine("测试通过");
}
else
{
Response.Write(msg);
//Console.WriteLine(msg);
}
}
}
[Flags]
public enum ValidateType
{
NotEmpty = 1,
MaxLength = 2,
MinLength = 4,
IsPhone = 8

}

[AttributeUsage(AttributeTargets.All, AllowMultiple = true)]
public class ValidateAttribute : Attribute
{
public ValidateAttribute(ValidateType validateType)
{
ValidateType = validateType;
}
private ValidateType validateType;
private int minLength;
private int maxLength;
public ValidateType ValidateType { get {return validateType;} set{validateType=value;} }
public int MinLength { get{return minLength;} set{minLength=value;} }
public int MaxLength { get { return maxLength; } set { maxLength = value; } }
}
public class ValidateModel
{
private ValidateType type;
private ValidateHelper.Func checkFunc;
private string errorMessage;
//private delegate bool func();
/// <summary>
/// 验证类型
/// </summary>
public ValidateType Type { get { return type; } set { type = value; } }
/// <summary>
/// 验证函数
/// </summary>
public ValidateHelper.Func CheckFunc { get { return checkFunc; } set { checkFunc = value; } }
/// <summary>
/// 错误信息
/// </summary>
public string ErrorMessage { get { return errorMessage; } set { errorMessage = value; } }
}
public class ValidateHelper
{
public delegate bool Func();
/// <summary>
/// 检查需要验证的函数是否通过
/// </summary>
/// <param name="checkType">被检查类型</param>
/// <param name="matchType">需要检查的类型</param>
/// <param name="func">检查函数</param>
/// <param name="errMessage">错误信息</param>
/// <returns>Emtpy 验证通过，否则返回错误信息</returns>
private static string CheckValidate(ValidateType checkType, ValidateType matchType, Func func, string errMessage)
{
if ((checkType & matchType) != 0)
{
if (func())
{
return errMessage;
}
}
return String.Empty;
}

/// <summary>
/// 检查对象是否通过验证
/// </summary>
/// <param name="entityObject">需要检查的对象</param>
/// <param name="errMessage">返回错误信息</param>
/// <returns>true:通过，false：失败</returns>
public static bool GetValidateResult(object entityObject, out string errMessage)
{
Type type = entityObject.GetType();
PropertyInfo[] properties = type.GetProperties();

string validateResult = string.Empty;
errMessage = string.Empty;
foreach (PropertyInfo property in properties)
{
object[] validateContent = property.GetCustomAttributes(typeof(ValidateAttribute), true);
if (validateContent != null)
{
object value = property.GetValue(entityObject, null);
foreach (ValidateAttribute validateAttribute in validateContent)
{
IList<ValidateModel> condition = new List<ValidateModel>();
//需要什么验证，在这里添加
ValidateModel vmode = new ValidateModel();
vmode.Type = ValidateType.NotEmpty;
vmode.CheckFunc = delegate { return (value == null || value.ToString().Length < 1); };
vmode.ErrorMessage = String.Format("元素{0}不能为空。", property.Name);
condition.Add(vmode);

vmode = new ValidateModel();
vmode.Type = ValidateType.MaxLength;
vmode.CheckFunc = delegate { return (value.ToString().Length > validateAttribute.MaxLength); };
vmode.ErrorMessage = String.Format("元素{0}长度不能超过{1}", property.Name, validateAttribute.MaxLength);
condition.Add(vmode);

vmode = new ValidateModel();
vmode.Type = ValidateType.MinLength;
vmode.CheckFunc = delegate { return (value.ToString().Length < validateAttribute.MinLength); };
vmode.ErrorMessage = String.Format("元素{0}长度不能小于{1}", property.Name, validateAttribute.MinLength);
condition.Add(vmode);

vmode = new ValidateModel();
vmode.Type = ValidateType.IsPhone;
vmode.CheckFunc = delegate { return (!System.Text.RegularExpressions.Regex.IsMatch(value.ToString(), @"^\d+$")); };
vmode.ErrorMessage = String.Format("元素{0}必须是电话号码", property.Name);
condition.Add(vmode);
//condition.Add(new ValidateModel { Type = ValidateType.NotEmpty, CheckFunc = () => { return (value == null || value.ToString().Length < 1); }, ErrorMessage = String.Format("元素{0}不能为空。", property.Name) });
//condition.Add(new ValidateModel { Type = ValidateType.NotEmpty, CheckFunc = () => { return (value == null || value.ToString().Length < 1); }, ErrorMessage = String.Format("元素{0}不能为空。", property.Name) });
//condition.Add(new ValidateModel { Type = ValidateType.MaxLength, CheckFunc = () => { return (value.ToString().Length > validateAttribute.MaxLength); }, ErrorMessage = String.Format("元素{0}长度不能超过{1}", property.Name, validateAttribute.MaxLength) });
//condition.Add(new ValidateModel { Type = ValidateType.MinLength, CheckFunc = () => { return (value.ToString().Length < validateAttribute.MinLength); }, ErrorMessage = String.Format("元素{0}长度不能小于{1}", property.Name, validateAttribute.MinLength) });
//condition.Add(new ValidateModel { Type = ValidateType.IsPhone, CheckFunc = () => { return (!System.Text.RegularExpressions.Regex.IsMatch(value.ToString(), @"^\d+$")); }, ErrorMessage = String.Format("元素{0}必须是电话号码", property.Name) });

foreach (ValidateModel model in condition)
{
validateResult = CheckValidate(
validateAttribute.ValidateType,
model.Type,
model.CheckFunc,
model.ErrorMessage
);
if (!string.IsNullOrEmpty(validateResult))
{
errMessage = validateResult;
return false;
}
}
}
}
}
return true;
}
}

public class User
{
private string password;
[Validate(ValidateType.IsPhone | ValidateType.MinLength | ValidateType.NotEmpty, MinLength = 5)]
public string Password { get { return password; } set { password = value; } }
}

有博友提到“System.ComponentModel.DataAnnotations命名空间中有很多用来验证的Attribute。”也能进行验证，但是自己是作为练习，多写一些代码也无妨。