代码之家 › 专栏 › 技术社区 › Darin Dimitrov

使用数据注释自定义依赖属性的模型验证

data-annotations asp.net-mvc-2 .net-3.5 validation

Darin Dimitrov · 技术社区 · 15 年前

从现在起我就用了 FluentValidation 用于验证模型类的库。在Web应用程序中,我将它与 jquery.validate 用于执行客户端验证的插件。一个缺点是,许多验证逻辑在客户端重复,不再集中在一个地方。

因为这个原因,我正在寻找另一种选择。有 many 举例说明 there 显示使用数据注释执行模型验证。看起来很有前途。我找不到的一件事是如何验证依赖于另一个属性值的属性。

以下面的模型为例:

public class Event
{
    [Required]
    public DateTime? StartDate { get; set; }
    [Required]
    public DateTime? EndDate { get; set; }
}

我想确保 EndDate 大于 StartDate . 我可以写一个习惯验证属性扩展 ValidationAttribute 以便执行自定义验证逻辑。不幸的是,我找不到一种方法来获得模型实例:

public class CustomValidationAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        // value represents the property value on which this attribute is applied
        // but how to obtain the object instance to which this property belongs?
        return true;
    }
}

我发现 CustomValidationAttribute 似乎是因为它有这个 ValidationContext 包含正在验证的对象实例的属性。很遗憾,此属性仅添加到.NET 4.0中。所以我的问题是:我能在.NET 3.5 SP1中实现相同的功能吗?

更新:

似乎 FluentValidation already supports ASP.NET MVC 2中的客户端验证和元数据。

不过,最好还是知道数据注释是否可以用于验证依赖属性。

5 回复 | 直到 10 年前

Travis Illig 15 年前

[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public sealed class PropertiesMustMatchAttribute : ValidationAttribute
{
    private const string _defaultErrorMessage = "'{0}' and '{1}' do not match.";

    private readonly object _typeId = new object();

    public PropertiesMustMatchAttribute(string originalProperty, string confirmProperty)
        : base(_defaultErrorMessage)
    {
        OriginalProperty = originalProperty;
        ConfirmProperty = confirmProperty;
    }

    public string ConfirmProperty
    {
        get;
        private set;
    }

    public string OriginalProperty
    {
        get;
        private set;
    }

    public override object TypeId
    {
        get
        {
            return _typeId;
        }
    }

    public override string FormatErrorMessage(string name)
    {
        return String.Format(CultureInfo.CurrentUICulture, ErrorMessageString,
            OriginalProperty, ConfirmProperty);
    }

    public override bool IsValid(object value)
    {
        PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(value);
        object originalValue = properties.Find(OriginalProperty, true /* ignoreCase */).GetValue(value);
        object confirmValue = properties.Find(ConfirmProperty, true /* ignoreCase */).GetValue(value);
        return Object.Equals(originalValue, confirmValue);
    }
}

[PropertiesMustMatch("NewPassword", "ConfirmPassword", ErrorMessage = "The new password and confirmation password do not match.")]
public class ChangePasswordModel
{
    public string NewPassword { get; set; }
    public string ConfirmPassword { get; set; }
}

Brad Wilson has a good example on his blog

Nick Riggs 15 年前

http://foolproof.codeplex.com/

public class Event
{
    [Required]
    public DateTime? StartDate { get; set; }

    [Required]
    [GreaterThan("StartDate")]
    public DateTime? EndDate { get; set; }
}

orcy 14 年前

http://devtrends.co.uk/blog/the-complete-guide-to-validation-in-asp.net-mvc-3-part-1

public class RegisterModel
{
    // skipped

    [Required]
    [ValidatePasswordLength]
    [DataType(DataType.Password)]
    [Display(Name = "Password")]
    public string Password { get; set; }                       

    [DataType(DataType.Password)]
    [Display(Name = "Confirm password")]
    [Compare("Password", ErrorMessage = "The password and confirmation do not match.")]
    public string ConfirmPassword { get; set; }
}

jwaliszko 10 年前

[Required]
public DateTime? StartDate { get; set; }    
[Required]
[AssertThat("StartDate != null && EndDate > StartDate")]
public DateTime? EndDate { get; set; }

can be found here

Steven 15 年前

public sealed class ContextScope : IDisposable 
{
    [ThreadStatic]
    private static object currentContext;

    public ContextScope(object context)
    {
        currentContext = context;
    }

    public static object CurrentContext
    {
        get { return context; }
    }

    public void Dispose()
    {
        currentContext = null;
    }
}

public class CustomValidationAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
         Event e = (Event)ObjectContext.CurrentContext;

         // validate event here.
    }
}

Event eventToValidate = [....];
using (var scope new ContextScope(eventToValidate))
{
    DataAnnotations.Validator.Validate(eventToValidate);
}