Question

我在

中使用MVC4进行基于自定义属性的验证

我可以使用propertyinfo []

使用以下代码在文本框中输入用户输入的值

PropertyInfo textBoxEnteredValue = validationContext.ObjectType.GetProperty("TxtCrossField");

但我无法获得用户选择的下拉值。

是否需要进行任何代码更改，请提示
object value在IsValid方法中为NULL。知道为什么会这样吗？

验证

   protected override ValidationResult IsValid(object value, ValidationContext validationContext)
   {             
       //Working
PropertyInfo textBoxEnteredValue = validationContext.ObjectType.GetProperty("TxtCrossField");

       //How to get the selected item? 
       PropertyInfo selectedDropdownlistvalue = validationContext.ObjectType.GetProperty("DDlList1");                
    }

模型

public class CrossFieldValidation
{        
    public string DDlList1
    { get; set; }

    // [Required(ErrorMessage = "Quantity is required")]
    [ValueMustbeInRange]
    [Display(Name = "Quantity:")]
    public string TxtCrossField
    { get; set; }
}

查看

@model MvcSampleApplication.Models.CrossFieldValidation
@{
    ViewBag.Title = "DdlCrossFields";
}   
<h2>DdlCrossFields</h2>
@using (Html.BeginForm("PostValues", "CrossFieldsTxtboxes"))
{   
    @Html.ValidationSummary(true)
    <div class ="editor-field">
      @Html.TextBoxFor(m => m.TxtCrossField)
       @Html.ValidationMessageFor(m=>m.TxtCrossField)
    </div>
  @*@Html.DropDownList("DDlList1",(IEnumerable<SelectListItem>)ViewBag.itemsforDropdown)*@        
      @Html.DropDownList("ItemsforDrop", ViewBag.ItemsforDrop as SelectList,"Select A state", new {id= "State"})

<input id="PostValues" type="Submit" value="PostValues" />
}

任何人都会建议任何关于这一点的想法...... 非常感谢....

Answer 1

负责接收已发布表单的方法应将您的模型作为参数。只要您的DDL绑定到该模型中的属性，您就可以获得所选的值，如下所示：

<强>控制器

[...some attributes...]
public static void MethodInController(YourModelType model)
{
   var selectedValue = model.DropDownListSelectedValue;
}

<强>模型

public class YourModelType
{
   public List<SomeType> DropDownOptions { get; set; }
   [YourValidationAttribute]
   public string DropDownListSelectedValue { get; set; }
}

验证属性类

public class YourValidationAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        //return based on conditions of "value"
    }
}

查看

@Html.DropDownListFor(model => model.DropDownListSelectedValue, model.DropDownListOptions)

获取用户选择的下拉值

1 个答案: