Some rule that should follow before starting the programming in c#
C# Programming Coding Standards :
How to follow the standards across the team
Indentation and Spacing
Good Programming practices
Architecture
ASP.NET
Comments
Exception Handling
How to follow the standards across the team:
The best approach is to have a team meeting and develop your own standards document. You may use this document as a template to prepare your own document.
Distribute a copy of this document (or your own coding standard document) prior to the coding standards meeting. All members should come to the meeting prepared to discuss pros and cons of the various points in the document. Make sure you have a manager present in the meeting to resolve conflicts.
Discuss all points in the document. Everyone may have a different opinion about each point, but at the end of the discussion, all members should agree on the standard that will be followed. Prepare a new standards document and distribute it to all team members.
After development commences, it is advisable to schedule code review meetings to ensure that everyone is following the rules. 3 types of code reviews are recommended:
1. Peer review – another team member reviews code to ensure that the code follows the coding standards and meets requirements. This level of review may also include unit testing. Each file in the project should go through this process.
2. Architect review – the architect of the team must review the core modules of the project to ensure that they adhere to the design and there are no “big” mistakes that can affect the project in the long run.
3. Group review – randomly select one or more files and conduct a group review once in a week. Distribute a printed copy of the files to all team members 30 minutes before the meeting. Let them read and come up with points for discussion. In the group review meeting, use a projector to display the file content in the screen. Go through every sections of the code and let every member give their suggestions on how could that piece of code can be written in a better way.
Naming Conventions and Standards
1. Use Pascal casing for Class names
public class HelloWorld
{
...
}
2. Use Pascal casing for Method names
void SayHello(string name)
{
...
}
3. Use Camel casing for variables and method parameters
int totalCount = 0;
void SayHello(string name)
{
string fullMessage = "Hello " + name;
...
}
4. Use the prefix “I” with Camel Casing for interfaces ( Example: IEntity )
5. Do not use Hungarian notation to name variables.
In earlier days most of the programmers liked it - having the data type as a prefix for the variable name and using m_ as prefix for member variables. Eg:
string m_sName;
int nAge;
However, in .NET coding standards, this is not recommended.
Usage of data type and m_ to represent member variables should not be used. All variables should use camel casing.
SSoommee pprrooggrraammmmeerrss ssttiillll pprreeffeerr ttoo uussee tthhee pprreeffiixx mm__ ttoo rreepprreesseenntt mmeemmbbeerr vvaarriiaabblleess,, ssiinnccee tthheerree iiss nnoo ootthheerr eeaassyy wwaayy ttoo iiddeennttiiffyy aa mmeemmbbeerr vvaarriiaabbllee..
6. Use Meaningful, descriptive words to name variables. Do not use abbreviations.
Good:
string address
int salary
Not Good:
string nam
string addr
int sal
7. Do not use single character variable names like i, n, s etc. Use names like index, temp
One exception in this case would be variables used for iterations in loops:
for ( int i = 0; i < count; i++ )
{
...
}
If the variable is used only as a counter for iteration and is not used anywhere else in the loop, many people still like to use a single char variable (i) instead of inventing a different suitable name.
8. Do not use underscores (_) for local variable names.
9. All member variables must be prefixed with underscore (_) so that they can be identified from other local variables.
10. Do not use variable names that resemble keywords.
11. Prefix boolean variables, properties and methods with “is” or similar prefixes.
Ex: private bool _isFinished
12. Namespace names should follow the standard pattern
<company name>.<product name>.<top level module>.<bottom level module>
13. Use appropriate prefix for the UI elements so that you can identify them from the rest of the variables.
There are 2 different approaches recommended here.
a. Use a common prefix ( ui_ ) for all UI elements. This will help you group all of the UI elements together and easy to access all of them from the intellisense.
b. Use appropriate prefix for each of the ui element. A brief list is given below. Since .NET has given several controls, you may have to arrive at a complete list of standard prefixes for each of the controls (including third party controls) you are using.
CCoonnttrrooll PPrreeffiixx LLaabbeell llbbll TTeexxttBBooxx ttxxtt DDaattaaGGrriidd ddttgg BBuuttttoonn bbttnn IImmaaggeeBBuuttttoonn iimmbb HHyyppeerrlliinnkk hhllkk DDrrooppDDoowwnnLLiisstt ddddll LLiissttBBooxx llsstt DDaattaaLLiisstt ddttll RReeppeeaatteerr rreepp CChheecckkbbooxx cchhkk CChheecckkBBooxxLLiisstt ccbbll RRaaddiiooBBuuttttoonn rrddoo RRaaddiiooBBuuttttoonnLLiisstt rrbbll IImmaaggee iimmgg PPaanneell ppnnll PPllaacceeHHoollddeerr pphhdd TTaabbllee ttbbll VVaalliiddaattoorrss vvaall
14. File name should match with class name (or namespace name).
For example, for the class HelloWorld, the file name should be helloworld.cs (or, helloworld.vb)
15. Use Pascal Case for file names.
Indentation and Spacing
1.Use TAB for indentation. Do not use SPACES. Define the Tab size as 4.
2. Comments should be in the same level as the code (use the same level of indentation).
Good:
// Format a message and display
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );
Not Good:
// Format a message and display
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );
3. Curly braces ( {} ) should be in the same level as the code outside the braces.
4. Use one blank line to separate logical groups of code.
Good:
bool SayHello ( string name )
{
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );
if ( ... )
{
// Do something
// ...
return false;
}
return true;
}
Not Good:
bool SayHello (string name)
{
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );
if ( ... )
{
// Do something
// ...
return false;
}
return true;
}
5. There should be one and only one single blank line between each method inside the class.
6. The curly braces should be on a separate line and not in the same line as if, for etc.
Good Programming practices
1. Avoid writing very long methods. A method should typically have 1~25 lines of code. If a method has more than 25 lines of code, you must consider refactoring into separate methods.
2. Method name should tell what it does. Do not use mis-leading names. If the method name is obvious, there is no need of documentation explaining what the method does.
Good:
void SavePhoneNumber ( string phoneNumber )
{
// Save the phone number.
}
Not Good:
// This method will save the phone number.
void SaveDetails ( string phoneNumber )
{
// Save the phone number.
}
3. A method should do only 'one job'. Do not combine more than one job in a single method, even if those jobs are very small.
Good:
// Save the address.
SaveAddress ( address );
// Send an email to the supervisor to inform that the address is updated.
SendEmail ( address, email );
void SaveAddress ( string address )
{
// Save the address.
// ...
}
void SendEmail ( string address, string email )
{
// Send an email to inform the supervisor that the address is changed.
// ...
}
Architecture
1. Always use multi layer (N-Tier) architecture.
2. Never access database from the UI pages. Always have a data layer class which performs all the database related tasks. This will help you support or migrate to another database back end easily.
3. Use try-catch in your data layer to catch all database exceptions. This exception handler should record all exceptions from the database. The details recorded should include the name of the command being executed, stored proc name, parameters, connection string used etc. After recording the exception, it could be re-thrown so that another layer in the application can catch it and take appropriate action.
4. Separate your application into multiple assemblies. Group all independent utility classes into a separate class library. All your database related files can be in another class library.
ASP.NET
1. Do not use session variables throughout the code. Use session variables only within the classes and expose methods to access the value stored in the session variables. A class can access the session using System.Web.HttpCOntext.Current.Session
2. Do not store large objects in session. Storing large objects in session may consume lot of server memory depending on the number of users.
3. Always use style sheets to control the look and feel of the pages. Never specify font name and font size in any of the pages. Use appropriate style class. This will help you to change the UI of your application easily in future. Also, if you like to support customizing the UI for each customer, it is just a matter of developing another style sheet for them
10. Comments
Good and meaningful comments make code more maintainable. However,
1. Do not write comments for every line of code and every variable declared.
2. Use // or /// for comments. Avoid using /* … */
3. Write comments wherever required. Good, readable code requires fewer comments. If all variables and method names are meaningful, that would make the code very readable and will not need many comments.
4. Do not write comments if the code is easily understandable without comment. The drawback of having lot of comments is that if you change the code and forget to change the comment, it will lead to more confusion.
5. Fewer lines of comments will make the code more elegant. But if the code is not clean/readable and there are less comments, that is worse.
6. If you have to use some complex or weird logic for any reason, document it very well with sufficient comments.
7. If you initialize a numeric variable to a special number other than 0, -1 etc, document the reason for choosing that value.
8. The bottom line is, write clean, readable code such a way that it doesn't need any comments to understand.
9. Perform spelling check on comments and also make sure proper grammar and punctuation is used.
Exception Handling
1. Never do a 'catch exception and do nothing'. If you hide an exception, you will never know if the exception happened or not. Many developers may use this handy method to ignore non significant errors. You should always try to avoid exceptions by checking all the error conditions programmatically. In any case, catching an exception and doing nothing is not allowed. In the worst case, you should log the exception and proceed.
2. In case of exceptions, give a friendly message to the user, but log the actual error with all possible details about the error, including the time it occurred, method and class name etc.
3. Always catch only the specific exception, not generic exception.
Good:
void ReadFromFile ( string fileName )
{
try
{
// read from file.
}
catch (FileIOException ex)
{
// log error.
// re-throw exception depending on your case.
throw;
}
}
Not Good:
void ReadFromFile ( string fileName )
{
try
{
// read from file.
}
catch (Exception ex)
{
// Catching general exception is bad... we will never know whether
// it was a file error or some other error.
// Here you are hiding an exception.
// In this case no one will ever know that an exception happened.
return "";
}
}
4. No need to catch the general exception in all your methods. Leave it open and let the application crash. This will help you find most of the errors during development cycle. You can have an application level (thread level) error handler where you can handle all general exceptions. In case of an 'unexpected general error', this error handler should catch the exception and should log the error in addition to giving a friendly message to the user before closing the application, or allowing the user to 'ignore and proceed'.
5. When you throw an exception, use the throw statement without specifying the original exception. This way, the original call stack is preserved.
Good:
catch
{
// do whatever you want to handle the exception
throw;
}
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