MVC開始日期和結束日期驗證

Question

我無法正常工作。我想允許用戶選擇start date和end date，如果start date大於end date我想要顯示一條錯誤消息。我正在使用MVC。這是我在模型上的代碼。

public class ModelClass : IValidatableObject 
{ 
    [Required(ErrorMessage = "ID Number is required")] 
    [Display(Name = "ID Number:")] 
    [RegularExpression(@"^(\d{13})$", ErrorMessage = "Enter a 13 digit ID number")] 
    public Int64 ID_Number { get; set; } 
    [Required(ErrorMessage = "The start date is required")] 
    [Display(Name = "Start Date:")] 
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")] 
    public DateTime Start_Date { get; set; } 
    [Required(ErrorMessage = "The end date is required")] 
    [Display(Name = "End Date:")] 
    [GreaterThan("Start_Date")] 
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")] 
    public DateTime End_Date { get; set; } 





    IEnumerable<ValidationResult> IValidatableObject.Validate(ValidationContext validationContext) 
    { 
     if (End_Date < Start_Date) 
     { 
      yield return new ValidationResult("EndDate must be greater than StartDate"); 
     } 
    } 
} 

Answer 1

這是你的模型應該如何看起來像：

public class ModelClass : IValidatableObject 
{ 
    [Required(ErrorMessage = "ID Number is required")] 
    [Display(Name = "ID Number:")] 
    [RegularExpression(@"^(\d{13})$", ErrorMessage = "Enter a 13 digit ID number")] 
    public Int64 ID_Number { get; set; } 
    [Required(ErrorMessage = "The start date is required")] 
    [Display(Name = "Start Date:")] 
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")] 
    public DateTime Start_Date { get; set; } 
    [Required(ErrorMessage = "The end date is required")] 
    [Display(Name = "End Date:")] 
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")] 
    public DateTime End_Date { get; set; } 


    IEnumerable<ValidationResult> IValidatableObject.Validate(ValidationContext validationContext) 
    { 
     if (End_Date < Start_Date) 
     { 
      yield return new ValidationResult("EndDate must be greater than StartDate"); 
     } 
    } 
} 

按下提交按鈕，我們需要檢查，該模型是有效的用戶之後。

ModelState.IsValid

會去您模式，並將驗證模型，如果樁模型是有效的（讓你在你的模型決定的規則），那麼它是有效的。

這是你的行動應該什麼樣子：

[HttpPost] 
public ActionResult Create(ModelClass modelClass) 
{ 
    if (ModelState.IsValid) 
    { 
     db.modelClass.Add(modelClass); 
     db.SaveChanges(); 
     return RedirectToAction("Index"); 
    } 

    return View(modelClass); 
}