ASP.NET Razor Partial Views: Creating Reusable Components for Web Pages

Learn how to use partial views in ASP.NET Razor to create reusable sections of code for your web applications. This tutorial explains the benefits of using partial views (code reusability, maintainability), how to create and use them, and best practices for building well-structured and efficient web pages.

ASP.NET Razor Partial Views

What are Partial Views?

ASP.NET lets you create reusable pieces of code for your web applications. These reusable components are called partial views. Think of them as small, self-contained sections of a webpage that you can include in multiple places.

A partial view is like a mini-template that you can plug into a larger view (your main webpage). It has the same file extension as other views: .cshtml.

When to Use Partial Views?

Use partial views when you have a large webpage with several repeating or logically separate sections. Breaking it down into smaller, manageable partial views makes your code cleaner and easier to maintain.

This follows the DRY (Don't Repeat Yourself) principle.

How to Use Partial Views

ASP.NET offers two ways to include partial views:

Method	Description
`Partial(String)`, `Partial(String, Object)`, etc.	Renders the partial view as an HTML-encoded string. There are several overloaded versions to handle different parameters.
`RenderPartial(String)`, `RenderPartial(String, Object)`, etc.	Renders the partial view using an HTML helper. It has a void return type and generally performs better than `Partial()`.

Creating a Partial View

To create a partial view, right-click on the Views folder (or a subfolder within it) in your project and select "Add" -> "View". This will create a new .cshtml file.

Example:

Let's say we have a registration form. We can split it into two parts: the main form and a section for email input. We'll make the email section a partial view.

Registration.cshtml (Main View):

Code

@{
    ViewBag.Title = "User Registration Form";
}

User Registration Form
@using (Html.BeginForm("Registration","Students"))
{
    @Html.Label("User Name", new { @class = "control-label col-sm-2" })
    @Html.TextBox("username", null, new { @class = "form-control" })
    @Html.Partial("PartialViewDemo") // Include the partial view
}

    

PartialViewDemo.cshtml (Partial View):

Code

@Html.Label("Email ID", new { @class = "control-label col-sm-2" })
@Html.TextBox("email", null, new { @class = "form-control" })

The @Html.Partial("PartialViewDemo") line in the main view includes the content of the partial view.

Output:

The resulting registration page will combine the main form and the email input from the partial view into a single form, allowing you to submit all the values together.