ASP.NET Core Views

Views are responsible for presenting data to the user. In ASP.NET Core, views are typically implemented using Razor syntax, which allows you to embed C# code within HTML markup.

Understanding Razor Views

Razor is a templating engine that simplifies the creation of dynamic web pages. It combines HTML markup with inline C# code using the @ symbol to denote code blocks and expressions.

Basic Razor Syntax

• @: Used to start a C# code expression or block.
• @{}: Used for multi-line C# code blocks.
• @Model: Accesses the model passed to the view.
• @Html: Provides helper methods for rendering HTML.

Example: Displaying Data

Imagine you have a model of type Product with properties like Name and Price. A Razor view could display this data like so:

@model YourApp.Models.Product

<h2>@Model.Name</h2>
<p>Price: @Model.Price.ToString("C")</p>
            

Layouts and Partial Views

Layouts

Layouts allow you to define a common structure for your web pages, such as headers, footers, and navigation menus. You can then render your view content within these layouts.

The _Layout.cshtml file is typically used as the main layout. The @RenderBody() directive in the layout file indicates where the content of the current view should be rendered.

Partial Views

Partial views are reusable view components that can be used to break down complex views into smaller, manageable pieces. They are also useful for rendering common UI elements across multiple views.

You can render a partial view within another view using the @Html.Partial() or @await Html.PartialAsync() methods.

<!-- In a main view -->
<div class="product-details">
    <h3>Details</h3>
    @await Html.PartialAsync("_ProductInfo", Model)
</div>

<!-- _ProductInfo.cshtml (Partial View) -->
@model YourApp.Models.Product
<p>@Model.Description</p>
            

View Components

View components are a powerful feature for building reusable UI fragments. They are similar to partial views but can also include their own logic and data retrieval, making them more self-contained.

View components consist of a class with a InvokeAsync method and a Razor view file.

Tag Helpers

Tag Helpers are a server-side HTML tag-based replacement for HTML helpers. They allow you to write HTML in a more familiar way while still benefiting from server-side logic.

Examples include:

• <label asp-for="PropertyName">
• <input asp-for="PropertyName">
• <a asp-controller="ControllerName" asp-action="ActionName">Link Text</a>

Working with Forms

ASP.NET Core provides excellent support for handling forms. You can use Tag Helpers to bind form elements to your model properties, making it easy to create, read, update, and delete data.

<form asp-controller="Products" asp-action="Create" method="post">
    <div class="form-group">
        <label asp-for="Name"></label>
        <input asp-for="Name" class="form-control" />
    </div>
    <button type="submit" class="btn btn-primary">Save</button>
</form>
            

This section covered the fundamentals of ASP.NET Core views, including Razor syntax, layouts, partial views, view components, and tag helpers. Understanding these concepts is crucial for building dynamic and interactive web applications.