将多个值绑定到单个复选框，并将其发布到控制器

Question

Model.cs

A campaign can have multiple images, that's why IEnumerable<int> ImageIdList .

public class Campaign
{
  public int Id { get; set; }
  public int CreatedBy { get; set; }
  public int UpdatedBy { get; set; }
  public IEnumerable<int> ImageIdList { get; set; }
}

View.cshtml

I want to download all the images related to a campaign, based on the ImageIdList , that's why I need to post all these ImageIds when a particular Campaign is checked and download button is clicked.

@model Campaign

    @{
      Layout = "....";
      var assets = Model.AssetsInCampaign.ToList();
    }
    @using (Html.BeginForm("action-method", "controller", FormMethod.Post))
    {
      <div class="btnSubmit">
        <input type="submit" value="Download Asset(s)" />
      </div>
      @foreach(var i in assets)
      {
        <div class="s_checkcol">
          <input type="checkbox" name="ids" />
          @foreach (var imageId in i.Where(c => c.AssetId == doc.FileDataId).SelectMany(c => c.ImageIdList))
          {
              <input type="hidden" name="ids" value=@(imageId)>
          }
        </div>
      }
    }

Controller.cs

public ActionResult DownloadFiles(IEnumerable<int> ids)
{
    // code
}

NOTE: Only a part of code(where I'm facing the problem) is provided here. Its a DB first approach and in no way I can alter that (ORDERS).

I tried the above, but all of the ids are posted to the controller no matter how many checkboxes are selected.

Question: How should I bind the IEnumerable<int> ImageIdList property to a checkbox in View.cs and post the data to Controller.cs so that only the ids of selected checkboxes are posted?

Answer 1

This is a nice practice... it will work and Iam working with such a manner ( Iam sure that it will work very well ) but one thing you have to be very carefull while coding this , little bit complicated

Iam taking this effort not only for as an answer to this particular question.

Its for all stackoverflow users. Because i never found the below method anyware in stackoverflow.

I get this method by a long search. You people can use this.

It will help you to avoid for loops to bind the Checkboxlist

Its the best good for re-usability ( need a single line (max: 20-25 chars to bind a CheckBoxList in Razor ))

CheckBoxListItem.cs

create a New Class CheckBoxListItem //you can use any other names

public class CheckBoxListItem
{
    public int ID { get; set; }
    public string Display { get; set; }
    public bool IsChecked { get; set; }
}

MyModel.cs

This is modelclass

public class MyModel
{
    [Key]        
    public int Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<CheckBoxListItem> ChkList { get; set; }
}

HomeController.cs

This is controller

public ActionResult Index()
{
     var model = new MyModel(){
         Id = 0,
         Name = "Your Name",
         ChkList = dbContext.myTable.Select(x => new CheckBoxListItem { ID = x.MyTableFieldID, Display = x.MyTableFieldName, IsChecked = true })
         //If you need only int part, then just avoid to bind data on Display field
     };
     return View(model);
}

[HttpPost]
public ActionResult Index(MyModel myModel) //Your model object on PostAction
{
    IEnumerable<CheckBoxListItem> ChkList = myModel.ChkList; 
    // Here is your answer, You can see all your check box items (both checked and unchecked) in ChkList, it will shows all your checked items are true and non-checked items are false in IsChecked field 
}

Here you have to give more patiance

Goto the Folder View > Shared > EditorTemplates and RightClick Add>View... and Create a new View with the same name CheckBoxListItem.cshtml

CheckBoxListItem.cshtml

@model Project.Models.CheckBoxListItem
<div class="">
    @Html.HiddenFor(x => x.ID)
    <div class="">
        @Html.CheckBoxFor(x => x.IsChecked)
    </div>
    @Html.LabelFor(x => x.IsChecked, Model.Display, new { @class = "" })
</div>

Create your View

Index.cshtml

@model @model Project.Models.MyModel

<div class="form-group">
    @Html.LabelFor(model => model.Id, htmlAttributes: new { @class = "" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.Id, new { htmlAttributes = new { @class = "" } })
        @Html.ValidationMessageFor(model => model.Id, "", new { @class = "" })
    </div>
</div>

@Html.EditorFor(model => model.ChkList) //This only one line of code is enough to bind a checkBoxList in future

<input type="submit" value="Create" class="" />

You will get all these in your post action