C# 编码规范和编程好习惯
C# 编码规范和编程好习惯
撰文:DotNetSpider.com(http://www.dotnetspider.com)
翻译:杨贺宏
谁都会写代码!几个月的编程经验可以让你写出“可运行应用程序”。让它可运行容易,但是以最有效率的方式编码就需要下更多的功夫!
要知道,大多数程序员在写”可运行代码,“而不是”高效代码“。我们在这个指南课程前面提到,你想成为你们公司”最尊贵的专业人员“吗?写”高效代码“是一项艺术,你必须学习和实践它。
命名惯例和规范
注记 :
Pascal 大小写形式-所有单词第一个字母大写,其他字母小写。
Camel 大小写形式-除了第一个单词,所有单词第一个字母大写,其他字母小写。
public class HelloWorld{ ...}
public class HelloWorld{ void SayHello(string name) { ... }}
public class HelloWorld{ int totalCount = 0; void SayHello(string name) { string fullMessage = "Hello " + name; ... }}
以前,多数程序员喜欢它-把数据类型作为变量名的前缀而m_作为成员变量的前缀。例如:
string m_sName;int nAge;然而,这种方式在.NET编码规范中是不推荐的。所有变量都用camel 大小写形式,而不是用数据类型和m_来作前缀。
- 别用缩写。用name, address, salary等代替 nam, addr, sal
- 别使用单个字母的变量象i, n, x 等. 使用 index, temp等
用于循环迭代的变量例外:
for ( int i = 0; i < count; i++ ){ ...}如果变量只用于迭代计数,没有在循环的其他地方出现,许多人还是喜欢用单个字母的变量(i) ,而不是另外取名。
- 变量名中不使用下划线 (_) 。
- 命名空间需按照标准的模式命名
. . .
例如,对于类HelloWorld, 相应的文件名应为 helloworld.cs (或, helloworld.vb)
缩进和间隔
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; }这段代码看起来比上面的好::
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; }
好:
if ( ... ) { // Do something }不好:
if ( ... ) { // Do something }
好:
if ( showResult == true ) { for ( int i = 0; i < 10; i++ ) { // } }不好:
if(showResult==true) { for(int i= 0;i<10;i++) { // } }
良好的编程习惯
遵从以下良好的习惯以写出好程序
好:
void SavePhoneNumber ( string phoneNumber ) { // Save the phone number. }
不好:
// This method will save the phone number. void SaveData ( string phoneNumber ) { // Save the phone number. }
好:
// 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. // ... }
不好:
// Save address and send an email to the supervisor to inform that the address is updated. SaveAddress ( address, email ); void SaveAddress ( string address, string email ) { // Job 1. // Save the address. // ... // Job 2. // Send an email to inform the supervisor that the address is changed. // ... }
好:
int age; string name; object contactInfo;
不好:
Int16 age; String name; Object contactInfo;
好:
enum MailType { Html, PlainText, Attachment } void SendMail (string message, MailType mailType) { switch ( mailType ) { case MailType.Html: // Do something break; case MailType.PlainText: // Do something break; case MailType.Attachment: // Do something break; default: // Do something break; } }
不好:
void SendMail (string message, string mailType) { switch ( mailType ) { case "Html": // Do something break; case "PlainText": // Do something break; case "Attachment": // Do something break; default: // Do something break; } }
注释
异常处理
好:
void ReadFromFile ( string fileName ) { try { // read from file. } catch (FileIOException ex) { // log error. // re-throw exception depending on your case. throw; } }不好:
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 ""; } }