At _Layout.cshtml used by all pages, when any background image is selected, I want to display the selected picture. But, I dont ,unfortunately, know how to pass this data to _Layout.cshtml.
AT _Layout.cshtml
<style type="text/css">
#body-bg {
background-image: url('//I want to change here');
}
</style>
How should i do? From any controller, this data should be pass to _Layout.cshtml but how?
The most robust way is using a base viewmodel class and put a string property to hold image path:
Model Class
public class BaseViewModel
{
public string BackgroundImage { get; set; }
}
_Layout.cshtml
#model BaseViewModel
<!DOCTYPE html>
<html>
<head>
<!-- other styles, meta tags, etc. -->
<style type="text/css">
#body-bg {
background-image: url('#Model.BackgroundImage');
}
</head>
<body>
<!-- body part -->
#RenderBody()
</body>
</html>
If you're using relative path (e.g. ~/Images/Selected.png) instead of absolute path to refer image paths, use UrlHelper.Content with string property as argument:
#body-bg {
background-image: url('#Url.Content(Model.BackgroundImage)');
}
Also don't forget to set viewmodel's string property inside controller action method:
public class HomeController : Controller
{
// other stuff
return View(new BaseViewModel { BackgroundImage = "/path/to/image.png" });
}
NB: You can use ViewBag or ViewData besides a viewmodel (they're both automatically passed to view), by changing Model to ViewBag/ViewData:
// View (CSS)
#body-bg {
background-image: url('#ViewBag.BackgroundImage');
}
// Controller
public class HomeController : Controller
{
// other stuff
ViewBag.BackgroundImage = "/path/to/image.png";
return View();
}
Note that ViewBag is dynamic, possibly extra check required to prevent NullReferenceException thrown when using ViewBag property.
References:
Passing Data to Views (MS Documentation)
Pass data to layout that are common to all pages
Passing Data to a Layout Page
I have a website which have a layout page. However this layout page have data which all pages model must provide such page title, page name and the location where we actually are for an HTML helper I did which perform some action. Also each page have their own view models properties.
How can I do this? It seems that its a bad idea to type a layout but how do I pass theses infos?
If you are required to pass the same properties to each page, then creating a base viewmodel that is used by all your view models would be wise. Your layout page can then take this base model.
If there is logic required behind this data, then this should be put into a base controller that is used by all your controllers.
There are a lot of things you could do, the important approach being not to repeat the same code in multiple places.
Edit: Update from comments below
Here is a simple example to demonstrate the concept.
Create a base view model that all view models will inherit from.
public abstract class ViewModelBase
{
public string Name { get; set; }
}
public class HomeViewModel : ViewModelBase
{
}
Your layout page can take this as it's model.
#model ViewModelBase
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Test</title>
</head>
<body>
<header>
Hello #Model.Name
</header>
<div>
#this.RenderBody()
</div>
</body>
</html>
Finally set the data in the action method.
public class HomeController
{
public ActionResult Index()
{
return this.View(new HomeViewModel { Name = "Bacon" });
}
}
I used RenderAction html helper for razor in layout.
#{
Html.RenderAction("Action", "Controller");
}
I needed it for simple string. So my action returns string and writes it down easy in view.
But if you need complex data you can return PartialViewResult and model.
public PartialViewResult Action()
{
var model = someList;
return PartialView("~/Views/Shared/_maPartialView.cshtml", model);
}
You just need to put your model begining of the partial view '_maPartialView.cshtml' that you created
#model List<WhatEverYourObjeIs>
Then you can use data in the model in that partial view with html.
Another option is to create a separate LayoutModel class with all the properties you will need in the layout, and then stuff an instance of this class into ViewBag. I use Controller.OnActionExecuting method to populate it.
Then, at the start of layout you can pull this object back from ViewBag and continue to access this strongly typed object.
Presumably, the primary use case for this is to get a base model to the view for all (or the majority of) controller actions.
Given that, I've used a combination of several of these answers, primary piggy backing on Colin Bacon's answer.
It is correct that this is still controller logic because we are populating a viewmodel to return to a view. Thus the correct place to put this is in the controller.
We want this to happen on all controllers because we use this for the layout page. I am using it for partial views that are rendered in the layout page.
We also still want the added benefit of a strongly typed ViewModel
Thus, I have created a BaseViewModel and BaseController. All ViewModels Controllers will inherit from BaseViewModel and BaseController respectively.
The code:
BaseController
public class BaseController : Controller
{
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActionExecuted(filterContext);
var model = filterContext.Controller.ViewData.Model as BaseViewModel;
model.AwesomeModelProperty = "Awesome Property Value";
model.FooterModel = this.getFooterModel();
}
protected FooterModel getFooterModel()
{
FooterModel model = new FooterModel();
model.FooterModelProperty = "OMG Becky!!! Another Awesome Property!";
}
}
Note the use of OnActionExecuted as taken from this SO post
HomeController
public class HomeController : BaseController
{
public ActionResult Index(string id)
{
HomeIndexModel model = new HomeIndexModel();
// populate HomeIndexModel ...
return View(model);
}
}
BaseViewModel
public class BaseViewModel
{
public string AwesomeModelProperty { get; set; }
public FooterModel FooterModel { get; set; }
}
HomeViewModel
public class HomeIndexModel : BaseViewModel
{
public string FirstName { get; set; }
// other awesome properties
}
FooterModel
public class FooterModel
{
public string FooterModelProperty { get; set; }
}
Layout.cshtml
#model WebSite.Models.BaseViewModel
<!DOCTYPE html>
<html>
<head>
< ... meta tags and styles and whatnot ... >
</head>
<body>
<header>
#{ Html.RenderPartial("_Nav", Model.FooterModel.FooterModelProperty);}
</header>
<main>
<div class="container">
#RenderBody()
</div>
#{ Html.RenderPartial("_AnotherPartial", Model); }
#{ Html.RenderPartial("_Contact"); }
</main>
<footer>
#{ Html.RenderPartial("_Footer", Model.FooterModel); }
</footer>
< ... render scripts ... >
#RenderSection("scripts", required: false)
</body>
</html>
_Nav.cshtml
#model string
<nav>
<ul>
<li>
Mind Blown!
</li>
</ul>
</nav>
Hopefully this helps.
There's another way to handle this. Maybe not the cleanest way from an architectural point of view, but it avoids a lot of pain involved with the other answers. Simply inject a service in the Razor layout and then call a method that gets the necessary data:
#inject IService myService
Then later in the layout view:
#if (await myService.GetBoolValue()) {
// Good to go...
}
Again, not clean in terms of architecture (obviously the service shouldn't be injected directly in the view), but it gets the job done.
You don't have to mess with actions or change the model, just use a base controller and cast the existing controller from the layout viewcontext.
Create a base controller with the desired common data (title/page/location etc) and action initialization...
public abstract class _BaseController:Controller {
public Int32 MyCommonValue { get; private set; }
protected override void OnActionExecuting(ActionExecutingContext filterContext) {
MyCommonValue = 12345;
base.OnActionExecuting(filterContext);
}
}
Make sure every controller uses the base controller...
public class UserController:_BaseController {...
Cast the existing base controller from the view context in your _Layout.cshml page...
#{
var myController = (_BaseController)ViewContext.Controller;
}
Now you can refer to values in your base controller from your layout page.
#myController.MyCommonValue
UPDATE
You could also create a page extension that would allow you to use this.
//Allows typed "this.Controller()." in cshtml files
public static class MyPageExtensions {
public static _BaseController Controller(this WebViewPage page) => Controller<_BaseController>(page);
public static T Controller<T>(this WebViewPage page) where T : _BaseController => (T)page.ViewContext.Controller;
}
Then you only have to remember to use this.Controller() when you want the controller.
#{
var myController = this.Controller(); //_BaseController
}
or specific controller that inherits from _BaseController...
#{
var myController = this.Controller<MyControllerType>();
}
I do not think any of these answers are flexible enough for a large enterprise level application. I'm not a fan of overusing the ViewBag, but in this case, for flexibility, I'd make an exception. Here's what I'd do...
You should have a base controller on all of your controllers. Add your Layout data OnActionExecuting in your base controller (or OnActionExecuted if you want to defer that)...
public class BaseController : Controller
{
protected override void OnActionExecuting(ActionExecutingContext
filterContext)
{
ViewBag.LayoutViewModel = MyLayoutViewModel;
}
}
public class HomeController : BaseController
{
public ActionResult Index()
{
return View(homeModel);
}
}
Then in your _Layout.cshtml pull your ViewModel from the ViewBag...
#{
LayoutViewModel model = (LayoutViewModel)ViewBag.LayoutViewModel;
}
<h1>#model.Title</h1>
Or...
<h1>#ViewBag.LayoutViewModel.Title</h1>
Doing this doesn't interfere with the coding for your page's controllers or view models.
if you want to pass an entire model go like so in the layout:
#model ViewAsModelBase
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta charset="utf-8"/>
<link href="/img/phytech_icon.ico" rel="shortcut icon" type="image/x-icon" />
<title>#ViewBag.Title</title>
#RenderSection("styles", required: false)
<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.3.min.js"></script>
#RenderSection("scripts", required: false)
#RenderSection("head", required: false)
</head>
<body>
#Html.Action("_Header","Controller", new {model = Model})
<section id="content">
#RenderBody()
</section>
#RenderSection("footer", required: false)
</body>
</html>
and add this in the controller:
public ActionResult _Header(ViewAsModelBase model)
Creating a base view which represents the Layout view model is a terrible approach. Imagine that you want to have a model which represents the navigation defined in the layout. Would you do CustomersViewModel : LayoutNavigationViewModel? Why? Why should you pass the navigation model data through every single view model that you have in the solution?
The Layout view model should be dedicated, on its own and should not force the rest of the view models to depend on it.
Instead, you can do this, in your _Layout.cshtml file:
#{ var model = DependencyResolver.Current.GetService<MyNamespace.LayoutViewModel>(); }
Most importantly, we don't need to new LayoutViewModel() and we will get all the dependencies that LayoutViewModel has, resolved for us.
e.g.
public class LayoutViewModel
{
private readonly DataContext dataContext;
private readonly ApplicationUserManager userManager;
public LayoutViewModel(DataContext dataContext, ApplicationUserManager userManager)
{
}
}
Other answers have covered pretty much everything about how we can pass model to our layout page. But I have found a way using which you can pass variables to your layout page dynamically without using any model or partial view in your layout. Let us say you have this model -
public class SubLocationsViewModel
{
public string city { get; set; }
public string state { get; set; }
}
And you want to get city and state dynamically. For e.g
in your index.cshtml you can put these two variables in ViewBag
#model MyProject.Models.ViewModel.SubLocationsViewModel
#{
ViewBag.City = Model.city;
ViewBag.State = Model.state;
}
And then in your layout.cshtml you can access those viewbag variables
<div class="text-wrap">
<div class="heading">#ViewBag.City #ViewBag.State</div>
</div>
You can also make use of RenderSection , it helps to you to inject your Model data into the _Layout view.
You can inject View Model Data, Json, Script , CSS, HTML etc
In this example I am injecting Json from my Index View to Layout View.
Index.chtml
#section commonLayoutData{
<script>
var products = #Html.Raw(Json.Encode(Model.ToList()));
</script>
}
_Layout.cshtml
#RenderSection("commonLayoutData", false)
This eliminates the need of creating a separate Base View Model.
Hope helps someone.
Why hasn't anyone suggested extension methods on ViewData?
Option #1
Seems to me by far the least intrusive and simplest solution to the problem. No hardcoded strings. No imposed restrictions. No magic coding. No complex code.
public static class ViewDataExtensions
{
private const string TitleData = "Title";
public static void SetTitle<T>(this ViewDataDictionary<T> viewData, string value) => viewData[TitleData] = value;
public static string GetTitle<T>(this ViewDataDictionary<T> viewData) => (string)viewData[TitleData] ?? "";
}
Set data in the page
ViewData.SetTitle("abc");
Option #2
Another option, making the field declaration easier.
public static class ViewDataExtensions
{
public static ViewDataField<string, V> Title<V>(this ViewDataDictionary<V> viewData) => new ViewDataField<string, V>(viewData, "Title", "");
}
public class ViewDataField<T,V>
{
private readonly ViewDataDictionary<V> _viewData;
private readonly string _field;
private readonly T _defaultValue;
public ViewDataField(ViewDataDictionary<V> viewData, string field, T defaultValue)
{
_viewData = viewData;
_field = field;
_defaultValue = defaultValue;
}
public T Value {
get => (T)(_viewData[_field] ?? _defaultValue);
set => _viewData[_field] = value;
}
}
Set data in the page. Declaration is easier than first option, but usage syntax is slightly longer.
ViewData.Title().Value = "abc";
Option #3
Then can combine that with returning a single object containing all layout-related fields with their default values.
public static class ViewDataExtensions
{
private const string LayoutField = "Layout";
public static LayoutData Layout<T>(this ViewDataDictionary<T> viewData) =>
(LayoutData)(viewData[LayoutField] ?? (viewData[LayoutField] = new LayoutData()));
}
public class LayoutData
{
public string Title { get; set; } = "";
}
Set data in the page
var layout = ViewData.Layout();
layout.Title = "abc";
This third option has several benefits and I think is the best option in most cases:
Simplest declaration of fields and default values.
Simplest usage syntax when setting multiple fields.
Allows setting various kinds of data in the ViewData (eg. Layout, Header, Navigation).
Allows additional code and logic within LayoutData class.
P.S. Don't forget to add the namespace of ViewDataExtensions in _ViewImports.cshtml
The best way to use static strings such as page title, page name and the location etc, is to define via ViewData. Just define required ViewData in ViewStart.cshtml
#{
Layout = "_Layout";
ViewData["Title"] = "Title";
ViewData["Address"] = "1425 Lane, Skardu,<br> Pakistan";
}
and call whenever require like
<div class="rn-info-content">
<h2 class="rn-contact-title">Address</h2>
<address>
#Html.Raw(ViewData["Address"].ToString())
</address>
</div>
You could create a razor file in the App_Code folder and then access it from your view pages.
Project>Repository/IdentityRepository.cs
namespace Infrastructure.Repository
{
public class IdentityRepository : IIdentityRepository
{
private readonly ISystemSettings _systemSettings;
private readonly ISessionDataManager _sessionDataManager;
public IdentityRepository(
ISystemSettings systemSettings
)
{
_systemSettings = systemSettings;
}
public string GetCurrentUserName()
{
return HttpContext.Current.User.Identity.Name;
}
}
}
Project>App_Code/IdentityRepositoryViewFunctions.cshtml:
#using System.Web.Mvc
#using Infrastructure.Repository
#functions
{
public static IIdentityRepository IdentityRepositoryInstance
{
get { return DependencyResolver.Current.GetService<IIdentityRepository>(); }
}
public static string GetCurrentUserName
{
get
{
var identityRepo = IdentityRepositoryInstance;
if (identityRepo != null)
{
return identityRepo.GetCurrentUserName();
}
return null;
}
}
}
Project>Views/Shared/_Layout.cshtml (or any other .cshtml file)
<div>
#IdentityRepositoryViewFunctions.GetCurrentUserName
</div>
In .NET Core, you can use View Components to do this.
https://learn.microsoft.com/en-us/aspnet/core/mvc/views/view-components?view=aspnetcore-5.0
From the link above, add a class Inheriting from ViewComponent
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ViewComponentSample.Models;
namespace ViewComponentSample.ViewComponents
{
public class PriorityListViewComponent : ViewComponent
{
private readonly ToDoContext db;
public PriorityListViewComponent(ToDoContext context)
{
db = context;
}
public async Task<IViewComponentResult> InvokeAsync(
int maxPriority, bool isDone)
{
var items = await GetItemsAsync(maxPriority, isDone);
return View(items);
}
private Task<List<TodoItem>> GetItemsAsync(int maxPriority, bool isDone)
{
return db.ToDo.Where(x => x.IsDone == isDone &&
x.Priority <= maxPriority).ToListAsync();
}
}
}
Then in your view (_layout in my case)
#await Component.InvokeAsync("PriorityList", new { maxPriority = 4, isDone = true })
If you need a view, make a folder at ~/Views/Shared/Components/<Component Name>/Default.cshtml. You need to make the folder Components then in that, make a folder with your component name. In the example above, PriorityList.
instead of going through this
you can always use another approach which is also fast
create a new partial view in the Shared Directory and call your partial view in your layout as
#Html.Partial("MyPartialView")
in your partial view you can call your db and perform what ever you want to do
#{
IEnumerable<HOXAT.Models.CourseCategory> categories = new HOXAT.Models.HOXATEntities().CourseCategories;
}
<div>
//do what ever here
</div>
assuming you have added your Entity Framework Database
what i did is very simple and it's works
Declare Static property in any controller or you can make a data-class with static values if you want like this:
public static username = "Admin";
public static UserType = "Administrator";
These values can be updated by the controllers based on operations.
later you can use them in your _Layout
In _layout.cshtml
#project_name.Controllers.HomeController.username
#project_name.Controllers.HomeController.UserType
It's incredible that nobody has said this over here. Passing a viewmodel through a base controller is a mess. We are using user claims to pass info to the layout page (for showing user data on the navbar for example).
There is one more advantage. The data is stored via cookies, so there is no need to retrieve the data in each request via partials.
Just do some googling "asp net identity claims".
You can use like this:
#{
ApplicationDbContext db = new ApplicationDbContext();
IEnumerable<YourModel> bd_recent = db.YourModel.Where(m => m.Pin == true).OrderByDescending(m=>m.ID).Select(m => m);
}
<div class="col-md-12">
<div class="panel panel-default">
<div class="panel-body">
<div class="baner1">
<h3 class="bb-hred">Recent Posts</h3>
#foreach(var item in bd_recent)
{
#item.Name
}
</div>
</div>
</div>
</div>
Firstly, I'm beginner of the MVC.
I have a controller named FinanceController. I have two views named StoreEvaluationForm and SendStoreEvaluationToPdf of this control. I want to call a first view's public static function, which is defined in #functions, from second view.
I guess views have hidden class in mvc. Because I realized when I mouse over first view's function, VS shows its class named _Page_Views_Finance_StoreEvaluationForm_cshtml and its namespace named ASP. However I couldn't find any way to accessing another view's function. In second view ASP namespace has only its class named _Page_Views_Finance_SendStoreEvaluationToPdf_cshtml.
To be clear, function in the view is a C# function not a javascript function. Its definition is:
#functions
{
public static string NumberFormatter(double? number, bool percent = false)
{
return number == null ? null : string.Format("{0}{1}", number.Value.ToString("N2"), percent ? "%" : null);
}
}
Yes, this can be achieved. I tried it with the default MVC project in Visual Studio 2015.
Content of About view:
#{
ViewBag.Title = "About";
}
#functions
{
public static string DoStuff()
{
return "Content from About view.";
}
}
Content of Index view:
#{
ViewBag.Title = "Home Page";
}
#_Page_Views_Home_About_cshtml.DoStuff()
... (other stuff)
In Index view there is a red squiggly line below _Page_Views_Home_About_cshtml displaying :
The name _Page_Views_Home_About_cshtml does not exist in the current context
Despite the error message, the application builds successfully and I can see the message from the About view when navigating to /Home/Index.
I am trying to access a class's properties that are within the main class (model).
Attempting this through #Html.RenderPartial but cannot seem to access the class within the class in the partial view - where am I going wrong in how to access the class lists properties?
main cshtml
#model Project.Models.BaseClass
#{
Layout = "~/Views/Shared/_Layout.cshtml";
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title></title>
</head>
<body>
<div class="ui-block-a">
<p>Heading</p>
<span>#{Html.RenderPartial("~/View/Path", Model);}</span>
</div>
</body
</html>
partial view - doesn't work
#model Project.Models.BaseClass.ChildClass
model
public class BaseClass
{
public List<ChildClass> childclasslist {get;set;}
}
public class ChildClass
{
public string name {get;set;}
}
In your main view you have the model from type BaseClass. So with the statement
#{Html.RenderPartial("~/View/Path", Model);}
you are giving the partial view the model BaseClass.
But your partial view expects a model from type
Project.Models.BaseClass.ChildClass
(which doesn't even exist, it would be Project.Models.ChildClass).
There are two options:
Change your partial view:
#model Project.Models.BaseClass
and access your list like
Model.childclasslist
or
Change your call to render the partial view:
#{Html.RenderPartial("~/View/Path", Model.childclasslist);}
and your partial view:
#model List<Project.Models.ChildClass>
How i can see, your ChildClass has similar namespace with BaseClass.
Try using correct namespace
#model Project.Models.ChildClass
I'm trying something new (to me) in using an abstract base class for my layout viewmodel.
The problem is that when I run the site as is, it throws a very cryptic (to me) exception. What does this exception mean, and what might I do to resolve it?
Layout
#model MyApp.Core.ViewModels.LayoutViewModel
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>#Model.Title</title>
</head>
<body>
<div>
#RenderBody()
</div>
</body>
</html>
Index
#model MyApp.Core.ViewModels.Home.IndexViewModel;
#{
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h1>#Model.Body</h1>
LayoutViewModel
namespace MyApp.Core.ViewModels
{
public abstract class LayoutViewModel
{
public string Title { get; set; }
}
}
IndexViewModel
namespace MyApp.Core.ViewModels.Home
{
public class IndexViewModel : LayoutViewModel
{
public string Body { get; set; }
}
}
Controller
[HttpGet]
public ActionResult Index()
{
var model = new IndexViewModel
{
Title = "Hello World",
Body = "Hello World"
};
return View(model);
}
And the Exception
Compilation Error Description: An error occurred during the
compilation of a resource required to service this request. Please
review the following specific error details and modify your source
code appropriately.
Compiler Error Message: CS1003: Syntax error, '>' expected
Source Error:
Line 27:
Line 28:
Line 29: public class _Page_Views_Home_Index_cshtml :
System.Web.Mvc.WebViewPage<FutureStateMobile.Core.ViewModels.Home.IndexViewModel;>
{
Line 30:
Line 31: #line hidden
Source File: c:\Users\Chase\AppData\Local\Temp\Temporary ASP.NET
Files\root\b314e0d7\36f522db\App_Web_index.cshtml.a8d08dba.yr7oemfz.0.cs
Line: 29
Compare and contrast:
Layout
#model MyApp.Core.ViewModels.LayoutViewModel
Index
#model MyApp.Core.ViewModels.Home.IndexViewModel;
Got it yet? Here's the answer:
one of them has a ; which shouldn't be there
I just add the line twice, and deleted... problem solved!
#model MyApp.Core.ViewModels.LayoutViewModel
#model MyApp.Core.ViewModels.Layout_OrOther_Model
Try to compile, you get an error (only one model blah, blah..)
Delete one of them.
#model MyApp.Core.ViewModels.LayoutViewModel
Compile.
That works for me!
bad:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<DSNY.Core.Interfaces.IUser>" %>
versus
good:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<DSNY.Core.Interfaces.IUser>>" %>
Compiler kept telling me it was expecting an extra >.