Introduction

Just follow the following steps in order implement multiselect dropdown with checkbox in AngularJS

Here In this article, I have used Visual Studio 2013

Step-1: Create New Project.

Go to File > New > Project > ASP.NET  Web Application (under web) > Entry Application Name > Click OK > Select Empty template > Checked MVC (under "Add folders and core references for" option) > OK

Step-2: Add a Database.

Go to Solution Explorer > Right Click on App_Data folder > Add > New item > Select SQL Server Database Under Data > Enter Database name > Add.

Step-3: Create a table.

In this example, I have used 1 table as below

Step-4: Add Entity Data Model.

Go to Solution Explorer > Right Click on Project name form Solution Explorer > Add > New item > Select ADO.net Entity Data Model under data > Enter model name > Add.
A popup window will come (Entity Data Model Wizard) > Select Generate from database > Next >
Chose your data connection > select your database > next > Select tables > enter Model Namespace > Finish.

Step-5: Create a javascript file for angular components.

Here I have created a folder named "Scripts" first, and then I have added a javascript file for add angular components (module, controller etc). Here we will fetch menu data from the database.
Right Click on your solution file (from solution explorer) > Add > New Folder > Renamed your folder. and then
Right click on your folder (just created) > Add > New Item > select "javascript" file > Enter name (here "MyApp.js")> Ok.
Write following code

var app = angular.module('MyApp', ['angularjs-dropdown-multiselect']);
app.controller('multiselectdropdown', ['$scope', '$http', function ($scope, $http) {
    //define object 
    $scope.CategoriesSelected = [];
    $scope.Categories = [];
    $scope.dropdownSetting = {
        scrollable: true,
        scrollableHeight : '200px'
    }
    //fetch data from database for show in multiselect dropdown
    $http.get('/home/getcategories').then(function (data) {
        angular.forEach(data.data, function (value, index) {
            $scope.Categories.push({ id: value.CategoryID, label: value.CategoryName });
        });
    })
    //post or submit selected items from multiselect dropdown to server
    $scope.SubmittedCategories = [];
    $scope.SubmitData = function () {
        var categoryIds = [];
        angular.forEach($scope.CategoriesSelected, function (value, index) {
            categoryIds.push(value.id);
        });

        var data = {
            categoryIds: categoryIds
        };

        $http({
            method: "POST",
            url: "/home/savedata",
            data:JSON.stringify(data)
        }).then(function (data) {
            $scope.SubmittedCategories = data.data;
        }, function (error) {
            alert('Error');
        })
    }
}])

Step-6: Create a Controller.

Go to Solution Explorer > Right Click on Controllers folder form Solution Explorer > Add > Controller > Enter Controller name > Select Templete "empty MVC Controller"> Add.

Here I have created a controller named "HomeController"

Step-7: Add new action into your controller for getting the view, where we will show a multiselect dropdown with checkboxes.

Here I have added "Index" Action into "Home" Controller. Please write this following code

public ActionResult Index()
{
    return View();
}

Step-8: Add an another action into your controller for getting data from a database for showing in multiselect dropdown.

public JsonResult getcategories()
{
    using (MyDatabaseEntities dc = new MyDatabaseEntities())
    {
        return new JsonResult { Data = dc.Categories.ToList(),  JsonRequestBehavior = JsonRequestBehavior.AllowGet };
    }
}

Step-9: Add one more action into your controller for post data (selected data from multiselect dropdown) to the server.

[HttpPost]
public JsonResult savedata(int[] categoryIds)
{
    //for make the application simple I am just sending back the selected categories from here
    // but you can do additional work here with categoryIds parameter
    List<Category> list = new List<Category>();
    if (categoryIds != null)
    {
        using (MyDatabaseEntities dc = new MyDatabaseEntities())
        {
            list = dc.Categories.Where(a => categoryIds.Contains(a.CategoryID)).ToList();
        }

        // do your additional work here
    }
    return new JsonResult { Data = list };
}

Step-10: Add view for your Action & design for showing multiselect dropdown list.

Right Click on Action Method (here right click on Index action) > Add View... > Enter View Name > Select View Engine (Razor) > Add.
HTML Code

@{
    ViewBag.Title = "Index";
}
<h2>Multiselect dropdown with checkbox in angularjs</h2>
      @* Load bootstrap css *@
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.2.0/css/bootstrap.min.css" />
      @* load angularjs library & lodash js *@
<script src="//cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.0/angular.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/2.4.1/lodash.js"></script>
        @* load our js ("MyApp" here) file and angularjs-dropdown-multiselect directive *@
<script src="~/Scripts/angularjs-dropdown-multiselect.js"></script>
<script src="~/Scripts/MyApp.js"></script>
        @* HTML Code *@

@* I have added some css here for looks good *@
<style>
    .body-content{padding-top:50px}
    .checkbox{padding:0;margin:0;}
    .dropdown-menu{overflow:auto !important;}
    .form-group div{display:inline-block; margin-right:10px}
</style>

<div ng-app="MyApp" ng-controller="multiselectdropdown">
    <div class="container" style="margin:50px">
        <form class="form-inline" name="myForm" role="form" ng-submit="SubmitData()">
            <div class="form-group">
                <label>Subscribe for categories : </label>
                @* Directive *@
                <div ng-dropdown-multiselect="" extra-settings="dropdownSetting" 
                     options="Categories" selected-model="CategoriesSelected" checkboxes="true"></div>
            </div>
            <button type="submit" class="btn btn-primary">Submit</button>
        </form>

        @* Show posted categories (from server) *@
        <div style="margin-top:40px" ng-if="SubmittedCategories.length > 0">
            <h2>Selected Categories</h2>
            <table class="table table-responsive table-bordered">
                <thead>
                    <tr>
                        <th>ID</th>
                        <th>Category Name</th>
                    </tr>
                </thead>
                <tbody>
                    <tr ng-repeat="cat in SubmittedCategories">
                        <td>{{cat.CategoryID}}</td>
                        <td>{{cat.CategoryName}}</td>
                    </tr>
                </tbody>
            </table>  
        </div>
    </div>
</div>

Step-11: Run application.