C# Layout Standards · CS-06

• Keep the length of each line under 130 characters.
• Keep one whitespace between keywords like if and the expression (Roslyn Analyzer Rule SA1000), but don’t add whitespaces after ( and before ) such as:

if (condition == null)

• Add a whitespace around operators, like +, -, ==, etc. (Roslyn Analyzer Rule SA1003)
• Always succeed the keywords if, else, do, while, for and foreach, with opening and closing braces (Roslyn Analyzer Rule ACL1006).
• Always put opening and closing braces on a new line (Roslyn Analyzer Rule SA1500).
• Put the entire LINQ statement on one line, or start each keyword at the same indentation (Roslyn Analyzer Rule SA1103), like this:

var query = from product in products where product.Price > 10 select product;

or

var query =
    from product in products
    where product.Price > 10
    select product;

• Start the LINQ statement with all the from expressions and don’t interweave them with where restrictions.
• Add parentheses around every comparison condition, but don’t add parentheses around a singular condition. For example

if (!String.IsNullOrEmpty(str) && (str != "new"))

• Add an empty line between multi-line statements, between members, after the closing parentheses, and between unrelated code blocks (Roslyn Analyzer Rules SA1513 and SA1516).

// Microsoft namespaces are first
using System;
using System.Collections;
using System.XML;

// Then any other namespaces in alphabetic order
using AvivaSolutions.Business;
using AvivaSolutions.Standard;

using Telerik.WebControls;
using Telerik.Ajax;

Roslyn Analyzer Rules SA1208 and SA1210

Maintaining a common order allows other team members to find their way in your code more easily. In general, a source file should be readable from top to bottom, as if you are reading a book. This prevents readers from having to browse up and down through the code file.

1. Private fields and constants
2. Public constants
3. Public read-only static fields
4. Events
5. Public Properties
6. Constructors and the Finalizer
7. Public and private methods, with related methods grouped together in calling order
   • For example, if three private methods are all called from a public method, the private methods should be located immediately beneath the public method in the order in which they are called

Regions can be helpful, but can also hide the main purpose of a class. Therefore, use #regions only for:

• Interface implementations (only if the interface is not the main purpose of that class)
• Grouping related test methods, if a test class has a large number of methods

Roslyn Analyzer Rule SA1124

A using statement can be prefixed with global to apply it to all files in a project. For example to automatically use System in all files, add the following statement to a file in the project:

global using System;

For consistency, a dedicated file must be used to store all global usings for a project. This file should be called GlobalUsings.cs and be located in the root of the project.

The ‘implicit usings’ feature implicitly adds certain using statements to all files based on the project type. It can be enabled in the .csproj:

<PropertyGroup>
    <ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>

For example, rather than a namespace block like this:

namespace Richard.Is
{
    public class Awesome
    {
    }
}

prefer a file-scoped namespace like this:

namespace Richard.Is;

public class Awesome
{
}

Roslyn Analyzer Rule IDE0161