.NET MVC 自定义日期验证器

Question

明天我将解决为我正在工作的会议应用程序编写自定义日期验证类的问题，该类将验证给定的开始或结束日期是否 A）小于当前日期，或 B）开始日期更大晚于会议结束日期（反之亦然）。

我认为这可能是一个相当普遍的要求。谁能给我指出一篇可能帮助我解决这个问题的博客文章的方向？

我正在使用 .net 3.5，所以我无法使用 .NET 4 中内置的新模型验证器 api。我正在处理的项目是 MVC 2。

更新：我正在编写的类需要扩展 System.ComponentModel .DataAnnotations 命名空间。在 .NET 4 中，您可以实现一个 IValidateObject 接口，这使得此类事情变得绝对轻而易举，但遗憾的是我无法使用 .Net 4。我如何在 .Net 3.5 中做同样的事情？

Answer 1

public sealed class DateStartAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        DateTime dateStart = (DateTime)value;
        // Meeting must start in the future time.
        return (dateStart > DateTime.Now);
    }
}

public sealed class DateEndAttribute : ValidationAttribute
{
    public string DateStartProperty { get; set; }
    public override bool IsValid(object value)
    {
        // Get Value of the DateStart property
        string dateStartString = HttpContext.Current.Request[DateStartProperty];
        DateTime dateEnd = (DateTime)value;
        DateTime dateStart = DateTime.Parse(dateStartString);

        // Meeting start time must be before the end time
        return dateStart < dateEnd;
    }
}

在您的视图模型中：

[DateStart]
public DateTime StartDate{ get; set; }

[DateEnd(DateStartProperty="StartDate")]
public DateTime EndDate{ get; set; }

在您的操作中，只需检查 ModelState.IsValid 即可。这就是你所追求的？

Answer 2

我知道这篇文章比较旧，但是我发现的这个解决方案要好得多。

如果对象是视图模型的一部分且具有前缀，则本文中接受的解决方案将不起作用。

即行

// Get Value of the DateStart property
string dateStartString = HttpContext.Current.Request[DateStartProperty];

可以在这里找到更好的解决方案：
ASP .NET MVC 3 验证使用自定义 DataAnnotation 属性：

新 DateGreaterThan 属性：

public sealed class DateGreaterThanAttribute : ValidationAttribute
{
    private const string _defaultErrorMessage = "'{0}' must be greater than '{1}'";
    private string _basePropertyName;

    public DateGreaterThanAttribute(string basePropertyName) : base(_defaultErrorMessage)
    {
        _basePropertyName = basePropertyName;
    }

    //Override default FormatErrorMessage Method
    public override string FormatErrorMessage(string name)
    {
        return string.Format(_defaultErrorMessage, name, _basePropertyName);
    }

    //Override IsValid
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        //Get PropertyInfo Object
        var basePropertyInfo = validationContext.ObjectType.GetProperty(_basePropertyName);

        //Get Value of the property
        var startDate = (DateTime)basePropertyInfo.GetValue(validationContext.ObjectInstance, null);

        var thisDate = (DateTime)value;

        //Actual comparision
        if (thisDate <= startDate)
        {
            var message = FormatErrorMessage(validationContext.DisplayName);
            return new ValidationResult(message);
        }

        //Default return - This means there were no validation error
        return null;
    }
}

用法示例：

[Required]
[DataType(DataType.DateTime)]
[Display(Name = "StartDate")]
public DateTime StartDate { get; set; }

[Required]
[DataType(DataType.DateTime)]
[Display(Name = "EndDate")]
[DateGreaterThanAttribute("StartDate")]
public DateTime EndDate { get; set; }

Answer 3

我认为应该这样做：

public boolean MeetingIsValid( DateTime start, DateTime end )
{
      if( start < DateTime.Now || end < DateTime.Now )
          return false;

      return start > end || end < start;
}

Answer 4

public ActionResult Index(vmemployee vme)

    {

        emplyee emp = new emplyee();
        vme.cities = new List<city>();

        vme.countries = new List<country>();

        vme.departments = new List<department>();

        Hrcontext context = new Hrcontext();
        vme.countries = context.cntentity.ToList();
        vme.cities = context.cityentity.ToList();
        vme.departments = context.deptentity.ToList();

        return View("employeelist", vme);
    }

    public ActionResult Index1(vmemployee vm)
    {

        vm.liemp = new List<emplyee>();
        return View("Searchemployee", vm);

    }
    [submit(Name = "sav")]
    public ActionResult save(vmemployee vme)
    {
        vme.cities = new List<city>();
        vme.countries = new List<country>();
        vme.departments = new List<department>();



        Hrcontext context = new Hrcontext();
        vme.countries = context.cntentity.ToList();
        vme.cities = context.cityentity.ToList();
        vme.departments = context.deptentity.ToList();
        vme.emp.Imagefile.SaveAs(@"C:\inetpub\wwwroot\hrsestem\hrsestem\images\" + vme.emp.Imagefile.FileName);
        vme.emp.Imagepath= (@"C:\inetpub\wwwroot\hrsestem\hrsestem\images\" + vme.emp.Imagefile.FileName);

        if (ModelState.IsValid == true)
        {
            context.empentity.Add(vme.emp);
            context.SaveChanges();
        }
        return View("employeelist", vme);
    }

Answer 5

public ActionResult Index()
    {
        
        return View("department1");
    }
    public ActionResult Savedata(Vmdepartment vm)
    {

        Hrcontext context = new Hrcontext();
        context.deptentity.Add(vm.dept);
        context.SaveChanges();

        return View("department1", vm);
    }
    public ActionResult Index1(Vmdepartment vm)
    {
        vm.liDepartment = new List<department>();
        
        return View("departmentview",vm);
    }

    public ActionResult search(Vmdepartment vm) {
        var n = vm.dept.name;
        vm.liDepartment = new List<department>();
        Hrcontext context = new Hrcontext();
        vm.liDepartment = context.deptentity.Where(a => a.name == n).ToList();
        return View("departmentview",vm);

    }
}