Introduction
Partial views render a portion of View content. A partial view is the same as a user control of a web form application. It is reusable like a user control. We can render a partial view using a HTML helper, they provide a method to render partial views. We can call a partial view using Html.Partial or Html.RenderPartial. Html.Partial renders the specified partial view as an HTML-encoded string, which means it returns the string. Html.RenderPartial renders the specified partial view using the specified HTML helper and it returns void.
In our example we a create layout with header, sidebar, content area and footer. Since a sidebar will be reused in the entire application, we create a partial view for that. Whenever we want to reuse a view in a web application, we should go with a partial view. Let's see a step-by-step implementation of partial view in layout.
Create a MVC project from the "Empty" template.
Right-click on "Controllers" and select "Add" >> "Controller...".
Select "MVC 5 Controller - Empty" to add an empty controller. Click on the "Add" button.
Name the controller as in the following:
Now we need to create a view.
Right-click on "Index" and select "Add View...".
Name the view and select "Empty (without model)" as the template.
Click on the "Add" button.
Right-click on "Views" and select "Add" >> "New Folder".
Name the folder "Shared", this will create a "Shared" folder under the view.
Right-click on the "Shared" folder and select "Add" >> "View…".
Name the view "_Layout" and select "Empty (without model)" as the template.
Design your desired layout in _Layout.cshtml.
Here we create a header, footer, side bar and content area. The header, footer and side bar should be shown in all pages, so we create them in _Layout.cshtml. The variable portion of the site is the content area, where content is changed dynamically. In ASP.NET we use a "ContentPlaceHolder", in the same way in MVC we use "RenderBody()".
Attach a layout page to Index.cshtml. Set the link of _Layout.cshtml in Index.cshtml.
Add the content in the body part of Index.cshtml.
Run the project and we can see the designed layout on the browser.
Now we want to render a partial view for the side bar portion.
Right-click on the "Shared" folder and select "Add" >> "View…".
Name the view "_SideMenu" and select "Empty (without model)" as the template.
Check "Create as a partial view" since it should be a partial view.
Design side menu portion, in other words add some page links to this portion.
Call a partial view using Html helper in the side bar table column. Here we can also use Html.RenderPartial instead of Html.Partial.
Run the project and you can see the partial view is rendered in the side bar.
