验证MVC中的Dropdownlist [英] Validating Dropdownlist in MVC

问题描述

我使用Entitiyframework绑定下拉列表，我想验证是否在点击按钮上选择了值

  public   class  DeviceModel 
 {
 [必需（ErrorMessage =  选择一个值）] 
  public  SelectList DeviceListModel { get ;  set ; } 
 
 [必需（ErrorMessage =  选择一个值）] 
  public  SelectList DeviceType { get ;  set ; } 
 
} 
 

  public  ActionResult Index（）
 {
 List< Example> mod =（ from  data  in  obj.Examples  select  data）。ToList（）; 
示例exp =  new 示例（）; 
 exp.Name =    - 选择 - ; 
 exp.ID =  0 ; 
 mod.Insert（ 0 ，exp）; 
 SelectList modeldata =  new  SelectList（mod，  ID， 名称， 0 ）; 
 DeviceModel objmodel =  new  DeviceModel（）; 
 objmodel.DeviceListModel = modeldata; 
列表< Gearhead_Type> types =（ from  data  in  obj.Gearhead_Type  select  data）。ToList（）; 
 Gearhead_Type GTypre =  new  Gearhead_Type（）; 
 GTypre.Name =    - 选择 - ; 
 GTypre.ID =  0 ; 
 types.Insert（ 0 ，GTypre）; 
 SelectList asd =  new  SelectList（类型，  ID， 名称， 0 ）; 
 objmodel.DeviceType = asd; 
 
  return 查看（objmodel）; 
 
} 
 

 <   div     class   =  form-group >  
 @ Html.Label（Gearhead Model and Type，新{@class =col-md-6 control-label，@ style =padding-left：200px}）
 @ Html.DropDownListFor（s => s.DeviceListModel，Model.DeviceListModel）
 @ Html.ValidationMessageFor（s => s.DeviceListModel）
  <   / div  >  
 

但是单击按钮时验证不起作用。

解决方案

检查出来：如何使用模型验证MVC 5中的Dropdownlist [ ^ ]

您需要检查模型在您的操作中是否有效，以及是否返回相同的视图和模型，以便显示错误消息。



http：// www .asp.net / mvc / overview / older-versions / getting-started-with-aspnet-mvc4 / adding-validation-to-the-model [ ^ ] br />


如果你想要客户端验证，那么谷歌asp.net mvc不引人注意的客户端验证，你会发现演练如何启用它。

你在你的页面上添加



< script src =@ Url.Content（〜 /Scripts/jquery.validate.min.js\")\"></script>

< script src =@ Url.Content（〜/ Scripts / jquery.validate.unobtrusive。 min.js ） >< /脚本>

I am binding a dropdown using Entitiyframework and i want to validate if the value is selected or not on a button click

public class DeviceModel
   {
       [Required(ErrorMessage = "Select a value")]
       public SelectList DeviceListModel { get; set; }

       [Required(ErrorMessage = "Select a value")]
       public SelectList DeviceType { get; set; }

   }

public ActionResult Index()
      {
          List<Example> mod = (from data in obj.Examples select data).ToList();
          Example exp = new Example();
          exp.Name = "--Select--";
          exp.ID = 0;
          mod.Insert(0, exp);
          SelectList modeldata = new SelectList(mod, "ID", "Name", 0);
          DeviceModel objmodel = new DeviceModel();
          objmodel.DeviceListModel = modeldata;
          List<Gearhead_Type> types = (from data in obj.Gearhead_Type select data).ToList();
          Gearhead_Type GTypre = new Gearhead_Type();
          GTypre.Name = "--Select--";
          GTypre.ID = 0;
          types.Insert(0, GTypre);
          SelectList asd = new SelectList(types, "ID", "Name", 0);
          objmodel.DeviceType = asd;

          return View(objmodel);

      }

<div class="form-group">
               @Html.Label("Gearhead Model and Type  ", new { @class = "col-md-6 control-label ", @style = "padding-left:200px" })
               @Html.DropDownListFor(s=>s.DeviceListModel,  Model.DeviceListModel)
               @Html.ValidationMessageFor(s => s.DeviceListModel)
           </div>

But the validation is not working in the button click.

解决方案

Check this out: How to validate Dropdownlist in MVC 5 using model[^]

You need to check if the model is valid in your action and if it isn't return the same view and model so the error messages can be shown.

http://www.asp.net/mvc/overview/older-versions/getting-started-with-aspnet-mvc4/adding-validation-to-the-model[^]

If you want client-side validation also then google "asp.net mvc unobtrusive client-side validation" and you'll find walkthroughs on how to enable it.

you Add On Your Page

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")"></script>

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