Main Razor Syntax Rules for C#

Main Razor Syntax Rules for C#

• Razor code blocks are enclosed in @{ ... }
• Inline expressions (variables and functions) start with @
• Code statements end with semicolon
• Variables are declared with the var keyword
• Strings are enclosed with quotation marks
• C# code is case sensitive
• C# files have the extension .cshtml

C# Example

<!-- Single statement block -->
@{ var myMessage = "Hello World"; }

<!-- Inline expression or variable -->
<p>The value of myMessage is: @myMessage</p>

<!-- Multi-statement block -->
@{
var greeting = "Welcome to our site!";
var weekDay = DateTime.Now.DayOfWeek;
var greetingMessage = greeting + " Here in Huston it is: " + weekDay;
}
<p>The greeting is: @greetingMessage</p>

What is Razor?

What is Razor?

Razor is a markup syntax that lets you embed server-based code (Visual Basic and C#) into web pages.

Server-based code can create dynamic web content on the fly, while a web page is written to the browser. When a web page is called, the server executes the server-based code inside the page before it returns the page to the browser. By running on the server, the code can perform complex tasks, like accessing databases.

Razor is based on ASP.NET, and designed for creating web applications. It has the power of traditional ASP.NET markup, but it is easier to use, and easier to learn.

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Razor Syntax

Razor uses a syntax very similar to PHP and Classic ASP.

Razor:

<ul>
@for (int i = 0; i < 10; i++) {
<li>@i</li>
}
</ul>

PHP:

<ul>
<?php
for ($i = 0; $i < 10; $i++) {
echo("<li>$i</li>");
}
?>
</ul>

Web Forms (and Classic ASP):

<ul>
<% for (int i = 0; i < 10; i++) { %>
<li><% =i %></li>
<% } %>
</ul> 

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Razor Helpers

ASP.NET helpers are components that can be accessed by single lines of Razor code.

You can build your own helpers using Razor syntax, or use built-in ASP.NET helpers.

Below is a short description of some useful Razor helpers:

• Web Grid
• Web Graphics
• Google Analytics
• Facebook Integration
• Twitter Integration
• Sending Email
• Validation

MVC Folders

MVC Folders

A typical ASP.NET MVC web application has the following folder content:

Application information Properties References Application folders App_Data Folder Content Folder Controllers Folder Models Folder Scripts Folder Views Folder Configuration files Global.asax packages.config Web.config

The folder names are equal in all MVC applications. The MVC framework is based on default naming. Controllers are in the Controllers folder, Views are in the Views folder, and Models are in the Models folder. You don't have to use the folder names in your application code.

Standard naming reduces the amount of code, and makes it easier for developers to understand MVC projects.

Below is a brief summary of the content of each folder:

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The App_Data Folder

The App_Data folder is for storing application data.

We will add an SQL database to the App_Data folder, later in this tutorial.

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The Content Folder

The Content folder is used for static files like style sheets (css files), icons and images.

Visual Web Developer automatically adds a themes folder to the Content folder. The themes folder is filled with jQuery styles and pictures. In this project you can delete the themes folder.

Visual Web Developer also adds a standard style sheet file to the project: the file Site.css in the content folder. The style sheet file is the file to edit when you want to change the style of the application.

We will edit the style sheet file (Site.css) file in the next chapter of this tutorial.

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The Controllers Folder

The Controllers folder contains the controller classes responsible for handling user input and responses.

MVC requires the name of all controller files to end with "Controller".

Visual Web Developer has created a Home controller (for the Home and the About page) and an Account controller (for Login pages):

We will create more controllers later in this tutorial.

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The Models Folder

The Models folder contains the classes that represent the application models. Models hold and manipulate application data.

We will create models (classes) in a later chapter of this tutorial.

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The Views Folder

The Views folder stores the HTML files related to the display of the application (the user interfaces).

The Views folder contains one folder for each controller. 

Visual Web Developer has created an Account folder, a Home folder, and a Shared folder (inside the Views folder).

The Account folder contains pages for registering and logging in to user accounts.

The Home folder is used for storing application pages like the home page and the about page.

The Shared folder is used to store views shared between controllers (master pages and layout pages).

 

We will edit the layout files in the next chapter of this tutorial.

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The Scripts Folder

The Scripts folder stores the JavaScript files of the application.

By default Visual Web Developer fills this folder with standard MVC, Ajax, and jQuery files:

MVC Introduction

MVC is one of three ASP.NET programming models.

MVC is a framework for building web applications using a MVC (Model View Controller) design:

• The Model represents the application core (for instance a list of database records).
• The View displays the data (the database records).
• The Controller handles the input (to the database records).

The MVC model also provides full control over HTML, CSS, and JavaScript.

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The MVC model defines web applications with 3 logic layers: The business layer (Model logic) The display layer (View logic) The input control (Controller logic)

The Model is the part of the application that handles the logic for the application data.
Often model objects retrieve data (and store data) from a database.

The View is the parts of the application that handles the display of the data.
Most often the views are created from the model data.

The Controller is the part of the application that handles user interaction.
Typically controllers read data from a view, control user input, and send input data to the model.

The MVC separation helps you manage complex applications, because you can focus on one aspect a time. For example, you can focus on the view without depending on the business logic. It also makes it easier to test an application.

The MVC separation also simplifies group development. Different developers can work on the view, the controller logic, and the business logic in parallel.