Base View Page in ASP.NET MVC 6

问题:

On ASP.NET MVC 5 I used a base ViewPage with a few properties:

public String PageTitle { get; set; } public String PageDescription { get; set; } public String[] BodyCssClasses { get; set; } 

Then on each view I would have:

@{   PageTitle = "Title ..."   PageDescription" = "Description ..."   BodyCssClasses = new String[] { "main", "home" } } 

On the master page I would simply use something like:

<title>@Title</title> 

With this approach I was able to use Strong Typed for page properties ...

Is it possible to use a Base View Page in ASP.NET MVC 6?

Since there is no Web.Config how could this be done?

Any suggestions for better options to define page head info is welcome.

UPDATE

I followed the suggested and I am using:

public abstract class ViewPageBase<TModel> : RazorPage<TModel> {   public String Title { get; set; } } // ViewPageBase 

Then on _ViewImports I have:

@inherits ViewPageBase<TModel> 

On _Layout.cshtml I have:

<title>@Title</title> 

And finally on a view which uses that layout I have:

@{   Title = "Page Title";   Layout = "_Layout"; } 

Everything compiles and runs but the page title is always empty.

Does anyone has any idea why?

回答1:

You'll probably want to make your base view page inherit from RazorPage.

public abstract class ViewPageBase<TModel> : RazorPage<TModel> { } 

Then you should be able to configure all your pages to inherit from this in the _ViewImports.cshtml file.

@inherits ViewPageBase<TModel> 

UPDATE

Not sure if this is the best approach, but I wonder if you could use the common ViewBag to share data between your View and the Layout.

Back the properties in your base page class with the ViewBag:

public abstract class ViewPageBase<TModel> : RazorPage<TModel> {     public string Title     {         get { return ViewBag.Title; }         set { ViewBag.Title = value; }     } } 

Set the property in your view:

@{     Title = "Home Page";  } 

Use the property in _Layout.cshtml:

<title>@Title</title> 

回答2:

The technique you have described in your update will technically work.

Unfortunately, as @Peter notes, you get one instance of your custom ViewPage for the view, and a different instance for the layout. Because you are using two different instances, you cannot set a property on the view and expect to access that property on the layout. That's the answer to your updated question:

Everything compiles and runs but the page title is always empty. Does anyone has any idea why?

@Peter has offered a work around using the ViewBag. I'd like to offer an additional workaround using dependency injection.

For instance, consider placing your custom properties in their own class, with its own interface:

public IPageMetaData {     string PageTitle { get; set; }     string PageDescription { get; set; }     string[] BodyCssClasses { get; set; } }  public PageMetaData : IPageMetaData {     public string PageTitle { get; set; }     public string PageDescription { get; set; }     public string[] BodyCssClasses { get; set; } } 

Now, register this with the .Net Core dependency injection framework. Use the Scoped lifecycle, so only one instance will be created per-web request. In a vanilla project, this takes place in Startup.cs, in the ConfigureServices method:

public void ConfigureServices(IServiceCollection services) {     // Add framework services.     services.AddMvc();     services.AddScoped<IPageMetaData, PageMetaData>(); } 

Finally, update your _ViewImports.cshtml file to inject this object into your views:

@inject Your.Namespace.Goes.Here.IPageMetaData MetaData; 

Now your views will have a ambient MetaData property that will correspond to a per-web request instance of the PageMetaData class. You can access it from both views and from the layout:

@{     // In a view     MetaData.PageTitle = "Set a page title"; }  @* In a layout *@ <title>@MetaData.PageTitle</title> 

回答3:

Sounds like you're looking for the @inherits Razor directive.

For instance:

@inherits MyBaseViewPage

文章来源: Base View Page in ASP.NET MVC 6