Naming Conventions for .NET / C# Projects

http://www.akadia.com/services/naming_conventions.html

Naming Conventions for .NET / C# Projects

Martin Zahn, Akadia AG, 20.03.2003

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The original of this document was developed by the Microsoft special interest group. We made some addons.

This document explains the naming conventions that should be used with .NET projects.

A consistent naming pattern is one of the most important elements of predictability and discoverability in a managed class library. Widespread use and understanding of these naming guidelines should eliminate unclear code and make it easier for developers to understand shared code.

Capitalization Styles Defined

We define three types of capitalization styles:

Pascal case

The first letter in the identifier and the first letter of each subsequent concatenated word are capitalized.

Example:

BackColor, DataSet

Camel case

The first letter of an identifier is lowercase and the first letter of each subsequent concatenated word is capitalized.

Example:

numberOfDays, isValid

Uppercase

All letters in the identifier are capitalized.

Example:

ID, PI

Hungarian Type Notation Defined

Hungarian notation is any of a variety of standards for organizing a computer program by selecting a schema for naming your variables so that their type is readily available to someone familiar with the notation. It is in fact a commenting technique.

Example:

strFirstName, iNumberOfDays

There are different opinions about using this kind of type notation in programming nowadays. Some say that it’s useful, and it should be used everywhere to enhance clarity of your code. Others say it just obfuscates your code, because it has no real advantage in modern programming environments.

Our point of view is a moderated one: use it wisely, meaning, we only use Hungarian notation for private or local variables, that are only accessible and interesting to the programmer of the class.

Don’t use it with public variables, properties or parameters in methods, because they are exposed to the outside world. Someone who uses your classes and accesses properties of your class, is not interested in type, but just wants to use them.

In the .NET framework, there are a lot of types, so we extended and adapted the Hungarian notation with our own type notation.

Naming Guidelines

1).  Private Variables (Fields in C#) Naming Guidelines

Naming guidelines

Prefix private variables with a "_" and Hungarian-style notation.

Case guidelines

Use camel case as a general rule, or uppercase for very small words

Example:

_strFirstName, _dsetEmployees

// Field
private OleDbConnection _connection;

// Property
public OleDbConnection Connection
{
  get { return _connection; }
  set { _connection = value; }
}

2).  Local Variables Naming Guidelines

Naming guidelines

Prefix private or local variables with Hungarian-style notation.

Case guidelines

Use camel case as a general rule, or uppercase for very small words

Example:

strFirstName, dsetEmployees

3).  Namespace Naming Guidelines

Naming guidelines

The general rule for naming namespaces is to use the company name followed by the technology name and optionally the feature and design as follows:

CompanyName.TechnologyName[.Feature][.Design]

Prefixing namespace names with a company name or other well-established brand avoids the possibility of two published namespaces having the same name. Use a stable, recognized technology name at the second level of a hierarchical name.

Example:

Akadia.Traffic, System.Web.UI, System.Windows.Forms

Case guidelines

Use Pascal case as a general rule, or uppercase for very small words.

Example:

System.Windows.Forms, System.Web.UI

4).  Class Naming Guidelines

Naming guidelines

Use a noun or noun phrase to name a class. 
Do not use a type prefix, such as C for class, on a class name.
Do not use the underscore character (_).

Case guidelines

Use Pascal case. Example:

FileStream, Button

5).  Interface Naming Guidelines

Naming guidelines

Prefix interface names with the letter "I", to indicate that the type is an interface.
Do not use the underscore character (_).

Case guidelines

Use Pascal case. Example:

IServiceProvider, IFormatable

6).  Parameter Naming Guidelines

Naming guidelines

Use descriptive parameter names. Parameter names should be descriptive enough that the name of the parameter and its type can be used to determine its meaning in most scenarios. To distinguish parameters from other variables the prefix "p" should be used.

Do not prefix parameter names with Hungarian type notation.

Do not use a prefix for parameter names of an event handler and exceptions.

Case guidelines

Use camel case. Example:

pTypeName, pNumberOfItems

7).  Method Naming Guidelines

Naming guidelines

Use verbs or verb phrases to name methods.

Case guidelines

Use Pascal case. Example:

RemoveAll(), GetCharAt()

8).  Property / Enumerations Naming Guidelines

Naming guidelines

Use a noun or noun phrase to name properties.
Do not use Hungarian notation.

Case guidelines

Use Pascal case. Example:

BackColor, NumberOfItems

9).  Event Naming Guidelines

Naming guidelines

Use an EventHandler suffix on event handler names.

Specify two parameters named sender and e. The sender parameter represents the object that raised the event. The sender parameter is always of type object, even if it is possible to use a more specific type. The state associated with the event is encapsulated in an instance of an event class named "e". Use an appropriate and specific event class for the e parameter type.

Name an event argument class with the EventArgs suffix.

Case guidelines

Use Pascal case. Example:

public delegate void MouseEventHandler(object sender, MouseEventArgs e);

9).  Exception Naming Guidelines

Naming guidelines

Event handlers in Visual Studio .NET tend to use an "e" parameter for the event parameter to the call. To ensure we avoid a conflict, we will use "ex" as a standard variable name for an Exception object.

Example

catch (Exception ex)
{
  // Handle Exception
}

10).   Constant Naming Guidelines

The names of variables declared class constants should be all uppercase with words separated by underscores. It is recommended to use a grouping naming schema.

Example (for group AP_WIN):

AP_WIN_MIN_WIDTH, AP_WIN_MAX_WIDTH, AP_WIN_MIN_HIGHT, AP_WIN_MAX_HIGHT

11). C# Primitive Type Notation

sbyte   sy
short   s
int     i
long    l
byte    y
ushort  us
uint    ui
ulong   ul
float   f
double  d
decimal dec
bool    b
char    c

12).  Visual Control Type Notation

Assembly                                asm
Boolean                                 bln
Button                                  btn
Char                                    ch
CheckBox                                cbx
ComboBox                                cmb
Container                               ctr
DataColumn                              dcol
DataGrid                                dgrid
DataGridDateTimePickerColumn            dgdtpc
DataGridTableStyle                      dgts
DataGridTextBoxColumn                   dgtbc
DataReader                              dreader
DataRow                                 drow
DataSet                                 dset
DataTable                               dtable
DateTime                                date
Dialog                                  dialog
DialogResult                            dr
Double                                  dbl
Exception                               ex
GroupBox                                gbx
HashTable                               htbl
ImageList                               iml
Integer                                 int
Label                                   lbl
ListBox                                 lbx
ListView                                lv
MarshallByRefObject                     rmt
Mainmenu                                mm
MenuItem                                mi
MDI-Frame                               frame
MDI-Sheet                               sheet
NumericUpDown                           nud
Panel                                   pnl
PictureBox                              pbx
RadioButton                             rbtn
SDI-Form                                form
SqlCommand                              sqlcom
SqlCommandBuilder                       sqlcomb
SqlConnection                           sqlcon
SqlDataAdapter                          sqlda
StatusBar                               stb
String                                  str
StringBuilder                           strb
TabControl                              tabctrl
TabPage                                 tabpage
TextBox                                 tbx
ToolBar                                 tbr
ToolBarButton                           tbb
Timer                                   tmr
UserControl                             usr
WindowsPrincipal                        wpl