为模型属性添加自定义错误消息

Question

有没有办法可以覆盖从控制器为模型属性抛出的默认验证错误？例如,car.make不能为null,但如果该人拼写汽车名称错误,我想抛出一个特定的错误:

模型

public class Car
{
    public int ID { get; set; }
    [Required]
    public string Make { get; set; }
}

视图

<div class="form-group">
       @Html.EditorFor(model => model.Make, new { htmlAttributes = new { @class = "form-control" } })
       @Html.ValidationMessageFor(model => model.Make, "", new { @class = "text-danger" })
</div>

CONTROLLER

public ActionResult Create([Bind(Include = "Make,Model")] Car car)
{
    ModelState.AddModelError("Car.Make", "Check your spelling");
    return View(car);
}

Answer 1

只需要修改ModelState.AddModelError("Car.Make", "Check your spelling");方法就好了

public ActionResult Create([Bind(Include = "Make,Model")] Car car)
{
     if(//Your Condition upon which you want to model validation throw error) {
        ModelState.AddModelError("Make", "Check your spelling");
      }
     if (ModelState.IsValid) {
       //Rest of your logic 
     }
   return View(car);
 }

更好的方法是将验证逻辑保持在控制器之外.如果您想这样做,您需要根据验证逻辑创建自定义注释.要创建自定义注释,您需要创建新类并ValidationAttribute在类中实现.

 public class SpellingAttributes: ValidationAttribute  
 {
 } 

下一步,您需要覆盖IsValid()并在其中写入验证逻辑

protected override ValidationResult IsValid(object value, ValidationContext validationContext)  
{  
    //validation logic 

   //If validation got success return ValidationResult.Success;
    return ValidationResult.Success;  
} 

在您的模型类中,您可以直接使用此注释

public class Car
{
     public int ID { get; set; }
     [Required]
     [Spelling(ErrorMessage ="Invalid Spelling")
     public string Make { get; set; }
}

有关如何在MVC中创建自定义注释的更多详细信息,您可以在此处参考我的博客希望它可以帮助您.