有没有办法重用数据注解？ [英] Is there a way to reuse data annotations?

问题描述

有没有实现数据域的想法（在属性级别），它在ASP.Net MVC 4视图作为模型类里面的方法？

Is there a way to implement the idea of a data domains (at a property level) inside of a class that is used as a model in a view in ASP.Net MVC 4?

考虑这个code：

public class LoginProfileModel {

    [DisplayName("Login ID")]
    [Required(ErrorMessage = "Login ID is required.")]
    public string LogonID { get; set; }

    [DisplayName("Password")]
    [Required(ErrorMessage = "Password cannot be blank.")]
    [StringLength(20, MinimumLength = 3)]
    [DataType(DataType.Password)]
    public string Password { get; set; }
}

下面是一个LoginProfileModel用于ASP.Net MVC 4.采用各种元数据/数据​​注解，这样我可以创建这个code干净的看法：

Here is a LoginProfileModel in for ASP.Net MVC 4. It uses a variety of metadata/data annotations so that I can create a clean view with this code:

@model myWebSite.Areas.People.Models.LoginProfileModel

@using ( Html.BeginForm( "Index" , "Login" ) ) {
    @Html.ValidationSummary()
    @Html.EditorForModel()
    <input type="submit" value="Login" />
}

我用一个登录ID，并在多个视图中的密码的想法，因此，在多个视图模型。我希望能够来定义的属性，一个密码使用，或者可能是密码本身与它的所有数据标注在一个位置，这样我可以重用那些在需要的地方，而不是每次使用时间respecifying他们的定义：

I use the idea of a "Login ID" and a "Password" in more than one view, and therefore, in more than one view model. I want to be able to define the attributes that a Password uses, or possibly the Password itself with all of it's data annotations in a single location so that I can reuse all those definitions where needed, rather than respecifying them every time they are used:

    [DisplayName("Password")]
    [Required(ErrorMessage = "Password cannot be blank.")]
    [StringLength(20, MinimumLength = 3)]
    [DataType(DataType.Password)]
    public string Password { get; set; }

这是可能的某种方式？

Is that possible some way?

推荐答案

下面的属性会影响您查看的验证过程。

The following attributes affect the validation process of your View.

[Required(ErrorMessage = "Password cannot be blank.")]
[StringLength(20, MinimumLength = 3)]

有关验证属性，你可以创建一个这样的类：

For the Validation attributes, you can create a class like this:

public class PasswordRuleAttribute : ValidationAttribute
    {    
        public override bool IsValid(object value)
        {

            if (new RequiredAttribute { ErrorMessage = "Password cannot be blank." }.IsValid(value) && new StringLengthAttribute(20) { MinimumLength=3 }.IsValid(value) )
                return true;

            return false;
        }
    }

您可以按如下方式使用它：

You can use it as follows:

[PasswordRule]
public string Password{get;set;}

这是你提到的是直接从属性类派生的，我不认为有一种方法将它们整合成一个单一属性的另外两个属性。

The other two attributes that you mentioned are Directly derived from the Attribute class, and I don't think there's a way to consolidate them into a single attribute.

我会尽快编辑更新你。

所以，现在我们只剩下：

So now we're left with:

[DisplayName("Password")]
[DataType(DataType.Password)]
[PasswordRule]
public string Password{get;set;}

编辑：

根据这篇文章：复合属性，这是不可能的合并属性。

According to this post: Composite Attribute, it's not possible to merge attributes.

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