I have a simple page that also includes a PartialView so that I can refresh the data every 10 seconds returned by the PartialView. It really is a trivial task but I'm not proficient enough with the whole web part and especially JavaScript.
How can I run the LoadData() Method every X seconds so that my partialView shows the data?
I have found the following JS code which I think should be able to refresh the PartialView but I don't know how to adapt this to my situation:
<script type="text/javascript">
$(function () {
setInterval(loadTable, 1000); // invoke load every second
loadTable(); // load on initial page loaded
});
function loadTable() {
$('#data').load('/controller/tabledata');
}
</script>
My index.cshtml looks like this:
#page
#model IndexModel
<div class="data">
<partial name="~/Pages/Shared/_BezoekersData.cshtml" />
</div>
The indexModel:
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.SharePoint.Client;
using PnP.Framework;
using System.Security;
namespace MyNameSpace.Pages
{
public class IndexModel : PageModel
{
public IActionResult OnGetPartial() => Partial("\\Shared\\_BezoekersData.cshtml");
// properties left out for clarity
public void OnGet()
{
LoadData();
}
public void LoadData()
{
// dataRetrieval part here.
}
}
}
_BezoekersData.cshtml:
#{
ViewData["Title"] = "Home page";
}
<div style="position:fixed; left:65px; top:25px; color:#c2a149; font-size:75px; ">#Model.Vestiging</div>
<div style="position:fixed; left:1100px; top:180px; color:#c2a149; font-size:50px">#Model.MaxAantal</div>
<div style="position:fixed; left:1100px; top:285px; color:#c2a149; font-size:50px">#Model.HuidigAantal</div>
You should add one more function to call the partial view and refresh it, check this:
public void OnGet()
{
LoadData();
}
public void LoadData()
{
MyModel=new MyModel {thetime=DateTime.Now };
}
public PartialViewResult OnGetMyPartial() // extra method to get data
{
MyModel = new MyModel { thetime = DateTime.Now };
return Partial("_BezoekersData", MyModel);
}
View:
Mind it must be ** div id="data"**, because you use #data to call jquery function.
Pass model data to partial, add model attribute.
And to call the new method, using handler:
In main view: #Model.MyModel.thetime
<div id="data">
<partial name="~/Pages/Shared/_BezoekersData.cshtml" model="Model.MyModel"/> //add a model attribute
</div>
#section Scripts
{
<script type="text/javascript">
$(function () {
setInterval(loadTable, 1000);
loadTable();
});
function loadTable() {
$('#data').load("/Index?handler=MyPartial"); //handler to call razor method
}
</script>
}
This is the partial view:
#model He621.Models.MyModel
In partial:<div style="position:fixed; left:65px; top:100px; color:#c2a149; font-size:75px; ">#Model.thetime</div>
Result:
The time refreshes every 1 seconds, and will only refresh the partial:
I'm implementing asp.net core project. I have a method in my controller that should pass a data to a viewcomponent and then I need that data to be displayed in _Layout razor view. Below is what I have tried till now:
public class AccountController : Controller {
public IActionResult Index(string str)
{
_httpContext.HttpContext.Items["Shared"] = str;
Debug.WriteLine("str:" + str);
Debug.WriteLine("HttpContext Index shared:"+_httpContext.HttpContext.Items["Shared"]);
// Use ViewData
ViewData["Shared"] = str;
Debug.WriteLine("ViewData Index shared:" + ViewData["Shared"]);
return View();
}
}
public class MySharedDataViewComponent : ViewComponent
{
private readonly IHttpContextAccessor _httpContext;
public MySharedDataViewComponent(IHttpContextAccessor context)
{
_httpContext = context;
}
public Task<IViewComponentResult> InvokeAsync()
{
Debug.WriteLine("MyShred data:" + _httpContext.HttpContext.Items["Shared"]);
return Task.FromResult<IViewComponentResult>(View(_httpContext.HttpContext.Items["Shared"]));
}
}
In index.cshtml for Account controller:
#model string
<h2>#Model</h2>
In Default.cshtml
#model dynamic
#{
var passedDataFromItems = (Model as string);
var passedDataFromViewData = (ViewData["Shared"] as string);
}
#passedDataFromItems
#passedDataFromViewData
In _Layout I added this:
<div class="col-sm-10 col-8 p-0 m-0 text-left">
#await Component.InvokeAsync("MySharedData")
</div>
And in startup I pasted what you suggested as well.
My problem is in _Layout there isn't any data from ViewComponent to be displayed.
First, you need to remove ( ) in _Layout.cshtml, just use #await ComponentAsync("SharedData"). Because ( ) will render HTMLEncoded string instead of HTML string.
Second, if you want to pass your shared data down from Controller, you don't need to call ViewComponent inside Controller. There are several way to pass, ex: HttpContext.Items or ViewData. You don't want to call render HTML from Controller. In previous .NET MVC, we have #Html.RenderAction() to render ChildControlOnly view in Controller. But this is removed, so there are no reason to use Controller to call ViewComponent. Let .NET Core handle that for you by Naming Convention
Third, you don't want to declare #{ Layout = null } in ViewComponent, it is useless because ViewComponent is as PartialView.
Not sure why you try to render whole HTML page in ViewComponent and put it in <head> tag in _Layout.cshtml.
Updated answer with sample code
In your _Layout.cshtml
<html>
<head>
</head>
<body>
<!-- Use this for calling ViewComponent, Name must be prefix of VC class -->
#await ComponentAsync("SharedData")
<!-- Use this for render Body -->
#RenderBody()
</body>
</html>
Example you have HomeController to render Home Page
public class HomeController : Controller
{
private readonly IHttpContextAccessor _httpContext;
public HomeController (IHttpContextAccessor context)
{
_httpContext = context;
}
/// <summary>
/// Define [Route] for parameterize
/// str? means Nullable Param
/// Ex: localhost/hello -> str = hello
/// </summary>
[Route("{str?}")]
public IActionResult Index(string str)
{
_httpContextAccessor.HttpContext.Items["Shared"] = str ?? "Items Empty Param";
ViewData["Shared"] = str ?? "View Data Empty Param";
return View();
}
}
Next you need to create Index.cshtml for placing #RenderBody()
<div>This is home page</div>
Next you need to create SharedDataViewComponentlocales on ViewComponents folder (Under root project)
public class SharedDataViewComponent : ViewComponent
{
private readonly IHttpContextAccessor _httpContext;
public SharedDataViewComponent(IHttpContextAccessor context)
{
_httpContext = context;
}
public Task<IViewComponentResult> InvokeAsync()
{
return Task.FromResult<IViewComponentResult>(View(_httpContext.HttpContext.Items["Shared"]));
}
}
In your Views\Shared\SharedData\Default.cshtml, write with these markup
#model dynamic
#{
var passedDataFromItems = (Model as string);
var passedDataFromViewData = (ViewData["Shared"] as string);
}
#passedDataFromItems
#passedDataFromViewData
Ensure in your Configure method in Startup.cs should add this line
services.AddHttpContextAccessor();
Trying to populate a select drop down list dynamically & every time I run it, I can step through the code just fine all the way through the #foreach block, but then it seems to get stuck in a continuous loop or something & will completely freeze up everything! Struggling because no error is even occurring.
"/api/Reps/Index" Controller works separately just fine. And I even updated it to just return one rep to see if that was an issue, but didn't make any difference.
*Note: Using MatBlazor to implement Material Design.
My .Razor Page:
#inject HttpClient Http
<EditForm Model="#projectParameters">
<DataAnnotationsValidator />
<ValidationSummary />
<div>
<MatSelect Label="Rep" #bind-Value="#projectParameters.Rep">
<MatOption Value="">Select</MatOption>
#foreach (var rep in repList)
{
<MatOption Value="#rep.id.ToString()">#rep.name</MatOption>
}
</MatSelect>
</div>
</EditForm>
#code
{
Project projectParameters = new Project();
private MyRep[] repList { get; set; }
protected override async Task OnInitAsync()
{
repList = await Http.GetJsonAsync<MyRep[]>
("/api/Reps/Index");
}
}
Here is my RepsController.cs code, too:
namespace MyProject.Controllers
{
public class RepsController : Controller
{
MyDataAccessLayer objrep = new MyDataAccessLayer();
[HttpGet]
[Route("api/Reps/Index")]
public IEnumerable<MyRep> Index()
{
return objrep.GetAllReps();
}
}
}
Just add #key attribute that equals to your option value, so code example:
<select>
<option #key="#rep.id" value="#rep.id">#rep.name</option>
</select>
I have database, which consists of table "Jobs": job_id (int, primary key), job_nm (nchar(50)).
In "Model" folder I add ADO.NET Entity data model.
Controller is:
namespace ListBox_proj.Controllers
{
public class HomeController : Controller
{
myDBEntities1 db = new myDBEntities1();
[HttpGet]
public ActionResult Index()`enter code here`
{
var jobs = db.Jobs;
ViewBag.Jobs = jobs;
return View(jobs);
}
[HttpPost]
public ActionResult Index(string sel1)
{
ViewBag.Result = sel1;
return View();
}
}
}
View is:
#{
ViewBag.Title = "Index";
}
<html>
<head>
<meta name="viewport" content="width=device-width"/>
<title>Index</title>
</head>
<body>
<h1 class="label">Please, select the job you interested in:</h1> <br /><br />
<select name="sel1" id ="sel1">
<option>All</option>
#foreach (var j in ViewBag.Jobs)
{
<option><p>#j.job_nm</p></option>
}
</select>
<form action="/home/index" method="post">
<input type="submit" value ="Search">
<input type="text">#ViewBag.Result</input>
</form>
</body>
</html>
but when I choose the item in selectbox, and push "Search", I have error message:
![enter image description here][1]
MESSAGE IN ENGLISH - Object reference not set to an instance of the object.
Please, help me! What I do wrong?
How Can I correct it?
You have two issues here.
The first is that ViewBag.Jobs is only being populated on the [HttpGet]; you will need to ensure that the ViewBag is also populated in [HttpPost]. A better solution generally would be to use a proper view model - for example,
public class JobViewModel {
public Jobs JobsList { get; set; }
public string Result { get; set; }
}
Simply populate that in both the [HttpGet] and [HttpPost] procedures, and pass it into the View() call. Then add:
#model JobsViewModel
at the top of the view to allow you to access it through the (strongly-typed) Model.JobsList property.
A secondary issue that you'll come across is that sel isn't being submitted, as it falls outside of your <form> tags - remember, the only information submitted in a form is that contained within it.
Restructure your view to:
<form action="/home/index" method="post">
<select name="sel1" id ="sel1">
<option>All</option>
#foreach (var j in Model.JobsList)
{
<option><p>#j.job_nm</p></option>
}
</select>
<input type="submit" value ="Search">
<input type="text">#Model.Result</input>
</form>
and that problem should also be solved.
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>