mvc4数据注释比较两个日期

时间：2013-11-09 19:49:35

标签： asp.net-mvc asp.net-mvc-4 data-annotations

我的模型中有这两个字段：

[Required(ErrorMessage="The start date is required")]
[Display(Name="Start Date")]
[DisplayFormat(DataFormatString = "{0,d}")]
public DateTime startDate { get; set; }

[Required(ErrorMessage="The end date is required")]
[Display(Name="End Date")]
[DisplayFormat(DataFormatString = "{0,d}")]
public DateTime endDate{ get; set; }

我要求endDate必须大于startDate。我尝试使用[Compare("startDate")]，但这仅适用于相同的操作。

“大于”操作应该使用什么？

3 个答案:

答案 0 :(得分：57)

查看Fluent Validation或MVC Foolproof Validation：这些可以为您提供很多帮助。

例如，使用Foolproof，您可以在日期属性中使用[GreaterThan("StartDate")]注释。

或者，如果您不想使用其他库，则可以通过在模型上实施IValidatableObject来实现自己的自定义验证：

public class ViewModel: IValidatableObject
{
    [Required]
    public DateTime StartDate { get; set; }
    [Required]    
    public DateTime EndDate { get; set; } 

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
       if (EndDate < StartDate)
       {
           yield return 
             new ValidationResult(errorMessage: "EndDate must be greater than StartDate",
                                  memberNames: new[] { "EndDate" });
       }
    }
}

答案 1 :(得分：11)

IValidatableObject接口为验证对象提供了一种实现IValidatableObject.Validate（ValidationContext validationContext）方法的方法。此方法始终返回IEnumerable对象。这就是你应该创建ValidationResult对象列表的原因，并将错误添加到此并返回。空列表表示验证您的条件。这在mvc 4中如下...... 

 public class LibProject : IValidatableObject
{
    [Required(ErrorMessage="Project name required")]

    public string Project_name { get; set; }
    [Required(ErrorMessage = "Job no required")]
    public string Job_no { get; set; }
    public string Client { get; set; }
    [DataType(DataType.Date,ErrorMessage="Invalid Date")]
    public DateTime ExpireDate { get; set; }


    IEnumerable<ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
    {
        List < ValidationResult >  res =new List<ValidationResult>();
        if (ExpireDate < DateTime.Today)
        {
            ValidationResult mss=new ValidationResult("Expire date must be greater than or equal to Today");
            res.Add(mss);

        }
        return res; 
    }
}

答案 2 :(得分：1)

我从Alexander Gore和JaimeMarín在一个相关的StackOverflow问题1中的回答中大量借用，创建了五个类，这些类可以使用GT，GE，EQ，LE和LT运算符比较同一模型中的两个字段（前提是他们实现了IComparable）。因此，例如，它可以用于日期，时间，整数和字符串对。

将这些全部合并到一个类中并以运算符作为参数会很好，但是我不知道如何。我留下了三个例外，因为如果抛出这三个例外，它们实际上代表的是表单设计问题，而不是用户输入问题。

您只需要像这样在模型中使用它，然后便是具有五个类的文件：

    [Required(ErrorMessage = "Start date is required.")]
    public DateTime CalendarStartDate { get; set; }

    [Required(ErrorMessage = "End date is required.")]
    [AttributeGreaterThanOrEqual("CalendarStartDate", 
        ErrorMessage = "The Calendar end date must be on or after the Calendar start date.")]
    public DateTime CalendarEndDate { get; set; }


using System;
using System.ComponentModel.DataAnnotations;

//Contains GT, GE, EQ, LE, and LT validations for types that implement IComparable interface.
//https://stackoverflow.com/questions/41900485/custom-validation-attributes-comparing-two-properties-in-the-same-model

namespace DateComparisons.Validations
{
    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
    public class AttributeGreaterThan : ValidationAttribute
    {
        private readonly string _comparisonProperty;
        public AttributeGreaterThan(string comparisonProperty){_comparisonProperty = comparisonProperty;}

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if(value==null) return new ValidationResult("Invalid entry");

        ErrorMessage = ErrorMessageString;

        if (value.GetType() == typeof(IComparable)) throw new ArgumentException("value has not implemented IComparable interface");
        var currentValue = (IComparable)value;

        var property = validationContext.ObjectType.GetProperty(_comparisonProperty);
        if (property == null) throw new ArgumentException("Comparison property with this name not found");

        var comparisonValue = property.GetValue(validationContext.ObjectInstance);
        if(!ReferenceEquals(value.GetType(), comparisonValue.GetType()))
            throw new ArgumentException("The types of the fields to compare are not the same.");

        return currentValue.CompareTo((IComparable)comparisonValue) > 0 ? ValidationResult.Success : new ValidationResult(ErrorMessage);
    }
}

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
public class AttributeGreaterThanOrEqual : ValidationAttribute
{
    private readonly string _comparisonProperty;
    public AttributeGreaterThanOrEqual(string comparisonProperty) { _comparisonProperty = comparisonProperty; }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value == null) return new ValidationResult("Invalid entry");
        ErrorMessage = ErrorMessageString;

        if (value.GetType() == typeof(IComparable)) throw new ArgumentException("value has not implemented IComparable interface");
        var currentValue = (IComparable)value;

        var property = validationContext.ObjectType.GetProperty(_comparisonProperty);
        if (property == null) throw new ArgumentException("Comparison property with this name not found");

        var comparisonValue = property.GetValue(validationContext.ObjectInstance);
        if (!ReferenceEquals(value.GetType(), comparisonValue.GetType()))
            throw new ArgumentException("The types of the fields to compare are not the same.");

        return currentValue.CompareTo((IComparable)comparisonValue) >= 0 ? ValidationResult.Success : new ValidationResult(ErrorMessage);

    }
}

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
public class AttributeEqual : ValidationAttribute
{
    private readonly string _comparisonProperty;
    public AttributeEqual(string comparisonProperty) { _comparisonProperty = comparisonProperty; }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value == null) return new ValidationResult("Invalid entry");
        ErrorMessage = ErrorMessageString;

        if (value.GetType() == typeof(IComparable)) throw new ArgumentException("value has not implemented IComparable interface");
        var currentValue = (IComparable)value;

        var property = validationContext.ObjectType.GetProperty(_comparisonProperty);
        if (property == null) throw new ArgumentException("Comparison property with this name not found");

        var comparisonValue = property.GetValue(validationContext.ObjectInstance);
        if (!ReferenceEquals(value.GetType(), comparisonValue.GetType()))
            throw new ArgumentException("The types of the fields to compare are not the same.");

        return currentValue.CompareTo((IComparable)comparisonValue) == 0 ? ValidationResult.Success : new ValidationResult(ErrorMessage);
    }
}

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
public class AttributeLessThanOrEqual : ValidationAttribute
{
    private readonly string _comparisonProperty;
    public AttributeLessThanOrEqual(string comparisonProperty) { _comparisonProperty = comparisonProperty; }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value == null) return new ValidationResult("Invalid entry");
        ErrorMessage = ErrorMessageString;

        if (value.GetType() == typeof(IComparable)) throw new ArgumentException("value has not implemented IComparable interface");
        var currentValue = (IComparable)value;

        var property = validationContext.ObjectType.GetProperty(_comparisonProperty);
        if (property == null) throw new ArgumentException("Comparison property with this name not found");

        var comparisonValue = property.GetValue(validationContext.ObjectInstance);
        if (!ReferenceEquals(value.GetType(), comparisonValue.GetType()))
            throw new ArgumentException("The types of the fields to compare are not the same.");

        return currentValue.CompareTo((IComparable)comparisonValue) <= 0 ? ValidationResult.Success : new ValidationResult(ErrorMessage);
    }
}

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
public class AttributeLessThan : ValidationAttribute
{
    private readonly string _comparisonProperty;
    public AttributeLessThan(string comparisonProperty) { _comparisonProperty = comparisonProperty; }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value == null) return new ValidationResult("Invalid entry");
        ErrorMessage = ErrorMessageString;

        if (value.GetType() == typeof(IComparable)) throw new ArgumentException("value has not implemented IComparable interface");
        var currentValue = (IComparable)value;

        var property = validationContext.ObjectType.GetProperty(_comparisonProperty);
        if (property == null) throw new ArgumentException("Comparison property with this name not found");

        var comparisonValue = property.GetValue(validationContext.ObjectInstance);
        if (!ReferenceEquals(value.GetType(), comparisonValue.GetType()))
            throw new ArgumentException("The types of the fields to compare are not the same.");

        return currentValue.CompareTo((IComparable)comparisonValue) < 0 ? ValidationResult.Success : new ValidationResult(ErrorMessage);
    }
}

}

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