[RegularExpression(@"Regular Expression Here", ErrorMessage = "Please input valid date format")]
public String RegualarExpressionField { get; set; }  

public class DateExpressionAttribute : RegularExpressionAttribute
{  public DateExpressionAttribute()  : base("Date Regular Expression Here")  {  }
} 

public class TestModel
{  [DateExpression]  public DateTime? DateField { get; set; }  [RegularExpression(@"Regular Expression Here", ErrorMessage = "Please input valid date format")]  public String RegualarExpressionField { get; set; }  

    <div><fieldset><legend>Account Information</legend><div class="editor-label">@Html.LabelFor(m => m.DateField)</div><div class="editor-field">@Html.TextBoxFor(m => m.DateField)@Html.ValidationMessageFor(m => m.DateField)</div><div class="editor-label">@Html.LabelFor(m => m.RegualarExpressionField)</div><div class="editor-field">@Html.TextBoxFor(m => m.RegualarExpressionField)@Html.ValidationMessageFor(m => m.RegualarExpressionField)</div><p><input type="submit" value="go!" /></p></fieldset></div>

运行之后会发现两个问题：①方案(2)中，客户端的验证没有被触发②即使输入完全符合正则表达式的值，两个方案经Server端验证后，全部返回验证的错误信息讨论：问题①的原因：我们在DateExpressionAttribute并没有实现IClientValidatable接口，故Client端的验证不会被触发；修改类如下：

    public class DateExpressionAttribute : RegularExpressionAttribute, IClientValidatable{public DateExpressionAttribute(): base(@"Your date regular expression here"){}public override string FormatErrorMessage(string name){return String.Format(CultureInfo.CurrentCulture,"The filed {0} should be a date", name);}public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context){var name = metadata.GetDisplayName();var rule = new ModelClientValidationRegexRule(FormatErrorMessage(name), Pattern);yield return rule;}}

    public class DateExpressionAttribute : RegularExpressionAttribute, IClientValidatable{public DateExpressionAttribute(): base(@"((^((1[8-9]\d{2})|([2-9]\d{3}))([-\/\._])(10|12|0?[13578])([-\/\._])(3[01]|[12][0-9]|0?[1-9])$)|(^((1[8-9]\d{2})|([2-9]\d{3}))([-\/\._])(11|0?[469])([-\/\._])(30|[12][0-9]|0?[1-9])$)|(^((1[8-9]\d{2})|([2-9]\d{3}))([-\/\._])(0?2)([-\/\._])(2[0-8]|1[0-9]|0?[1-9])$)|(^([2468][048]00)([-\/\._])(0?2)([-\/\._])(29)$)|(^([3579][26]00)([-\/\._])(0?2)([-\/\._])(29)$)|(^([1][89][0][48])([-\/\._])(0?2)([-\/\._])(29)$)|(^([2-9][0-9][0][48])([-\/\._])(0?2)([-\/\._])(29)$)|(^([1][89][2468][048])([-\/\._])(0?2)([-\/\._])(29)$)|(^([2-9][0-9][2468][048])([-\/\._])(0?2)([-\/\._])(29)$)|(^([1][89][13579][26])([-\/\._])(0?2)([-\/\._])(29)$)|(^([2-9][0-9][13579][26])([-\/\._])(0?2)([-\/\._])(29)$))"){}public override bool IsValid(object value){return true;}public override string FormatErrorMessage(string name){return String.Format(CultureInfo.CurrentCulture,"The filed {0} should be a date", name);}public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context){var name = metadata.GetDisplayName();var rule = new ModelClientValidationRegexRule(FormatErrorMessage(name), Pattern);yield return rule;}}