Bootstrap模态覆盖无法覆盖ASP.NET MVC中的“布局”页面

Question

我在ASP.Net MVC项目中使用Bootstrap Modal，它工作正常，但问题在于Modal的覆盖层仅覆盖页面，而不能覆盖布局页面和导航栏， 我有版面页面，我在子页面中使用模态

<!-- The Modal -->
            <div id="myModal" class="modal">

                <!-- Modal content -->
                <div class="modal-content">
                    <div class="modal-header">
                        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
                        <h4 class="modal-title">Confirmation</h4>
                    </div>
                    <div class="modal-body">
                        <p>Do you want to save changes you made to document before closing?</p>
                        <p class="text-warning"><small>If you don't save, your changes will be lost.</small></p>
                    </div>
                    <div class="modal-footer">
                        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
                        <button type="button" class="btn btn-primary">Save changes</button>
                    </div>
                </div>

            </div>