18th Chapter View

1.IView interface

2.IViewEngine interface

Viewengineresult

3. Registering the View engine

            // clear the View engine             ViewEngines.Engines.Clear ();             // Add a view engine            VIEWENGINES.ENGINES.ADD (new  debugdataviewengine ());             // or  Add View engine (order)            ViewEngines.Engines.Insert (0,new debugdataviewengine ());

The MVC framework support for view engines is implemented by the Controlleractioninvoker class and is built into the Iactioninvoker interface. When

When you implement your own action Invoker or controller factory directly via the Iactioninvoker or Icontrollerfactory interface, you will not be able to access the view engine features automatically.

First, using the Razor view engine

The Razor view engine compiles the view of the application to improve performance. The view is converted to a C # class and then compiled, which is why it is convenient to include C # snippets in the view.

　　1. Configure the View search location

Razor View engine Search properties

Property	Describe	Default value
Viewlocationformats Masterlocationformats Partialviewlocationformats	Find views, partial views, and location of layouts	"~/views/{1}/{0}.cshtml", "~/views/{1}/{0}.vbhtml", "~/views/shared/{0}.cshtml", "~/views/shared/{0}.vbhtml"
Areaviewlocationformats Areamasterlocationformats Areapartialviewlocationformats	Find a view, a partial view, and the location of a layout for a region	"~/areas/{2}/views/{1}/{0}.cshtml", "~/areas/{2}/views/{1}/{0}.vbhtml", "~/areas/{2}/views/shared/{0}.cshtml", "~ /areas/{2}/views/shared/{0}.vbhtml "

The parameter value corresponding to the dot character:

{0} represents the view name

{1} represents the controller name

{2} represents a zone domain name

Create a derived class of the Razorviewengine class and modify the property values to change the search location. (To re-register the View engine)

 Public class Customlocationviewengine:razorviewengine    {        public  customlocationviewengine ()        {            newstring[]            {                "~/views/{1}/{0}.cshtml",                " ~/views/common/{0}.cshtml "             };        }    }

       protected void Application_Start ()        {            arearegistration.registerallareas ();           ViewEngines.Engines.Clear ();            VIEWENGINES.ENGINES.ADD (new   customlocationviewengine ());            Webapiconfig.register (globalconfiguration.configuration);            Filterconfig.registerglobalfilters (globalfilters.filters);            Routeconfig.registerroutes (routetable.routes);            Bundleconfig.registerbundles (bundletable.bundles);        }

2. Add Dynamic content

How to add dynamic content

Technology	When to use
Inline code	Used for small, self-contained view-logic fragments, such as an if or foreach statement. This is the basic figure for creating dynamic content, and it is also the basis for some other methods.
HTML helper Methods	Used to generate a separate HTML element or collection of small fragments, typically based on the values of the view model or view data. MVC contains a number of useful HTML helper methods, and it's easy to create your own helper method methods.
Segmentation	Used to create content segmentation, which is used to insert to a specific location in the layout
Partial view	The child fragment markers that are used to share between views. Partial views can also contain inline code, HTML helper methods, and references to other partial views. Partial views do not invoke action methods, so they cannot be used to perform transaction logic
Child action	Used to create reusable UI controls, or to require widgets that contain transactional logic. When a child action is used, it invokes an action method, returns a view, and injects the result into the response stream

　　　　1. Segmentation (Section): provides a content area for a layout. Inserts a portion of the view into the layout.

When Razor parses a layout, the Rendersection helper method displays the segmented contents of the specified name in the view. Segmented content that is not included in the view is inserted where the Renderbody helper is used in the layout.

　　　　Note: A view can only define segments that are referenced in a layout. An exception is thrown if you attempt to define a segment in a view that does not have a corresponding @rendersection helper call in the layout.

(1) layout (_layout.cshtml) to determine whether a segment is defined in the view:

@if (issectiondefined ("header")) {   @RenderSection ("header  ")}  else  {     } 

(2) Optional segment: @RenderSection ("script", false)

2. Partial view (section): many different places in the application use the same razor tags and html tag fragments.

Partial views render content in the layout.

Partial View strongpartial.cshtml

        @model ienumerable<string>       <div>              The information here is from the partial           view <ul>               @ foreach (string in Model)               {                   <li> @str </li>               }            </ul>       </div>    

Using partial views: in List.html

@{Viewbag.title="List"; Layout=NULL; }                @* @Html. Partial ("mypartial")*@ @Html. Partial ("strongpartial",New[]        {            "Apple","Orange","Pear"        })                                                                                        

3. Child action: The action method that is called through the view. A controller logic is used in multiple places in the application.

(1) Define the sub-action method:

        [childactiononly]        public  actionresult time (DateTime time)        {             return Partialview (time);        }

To add a child action view:

        @model DateTime          <p>           Present time: @Model. toshorttimestring ()          </p>

(2) Render child action:

        @Html. Action ("Time", "Home", New{time=datetime.now)

18th Chapter View