C++
中，cȝ使用者决定了(jin)cȝ实例内存?sh)(x)如何分配，分配在堆上还是栈上。我们先看一D例子程序：(x)
#include
"stdio.h"
class
Demo{
public
:
(tng) (tng) (tng)
int i;
(tng) (tng) (tng)
char* objName;
(tng) (tng) (tng) Demo(){
(tng) (tng) (tng) (tng) (tng) (tng) (tng) objName = "Default object.";
(tng) (tng) (tng) (tng) (tng) (tng) (tng) printf("%s, objName = %s\r\n", "Enter Demo default ctor. method.", objName);
(tng) (tng) (tng) (tng) (tng) (tng) (tng)
(tng) (tng) (tng) (tng) (tng) (tng) (tng) i = 1000;
(tng) (tng) (tng) }
(tng) (tng) (tng) Demo(int ival, char* name){
(tng) (tng) (tng) (tng) (tng) (tng) (tng) printf("%s,i = %d, objName = %s\r\n", "Enter Demo(int ival) ctor method", ival, name);
(tng) (tng) (tng) (tng) (tng) (tng) (tng) i = ival;
(tng) (tng) (tng) (tng) (tng) (tng) (tng) objName = name;
(tng) (tng) (tng) }
(tng) (tng) (tng) Demo(const Demo& d){
(tng) (tng) (tng) (tng) (tng) (tng) (tng) printf("%s\r\n", "Enter Demo copy ctor method.");
(tng) (tng) (tng) (tng) (tng) (tng) (tng) i = d.i;
(tng) (tng) (tng) (tng) (tng) (tng) (tng) objName = "copied d";
(tng) (tng) (tng) }
(tng) (tng) (tng) ~Demo(){
(tng) (tng) (tng) (tng) (tng) (tng) (tng) printf("%s, i = %d, objName = %s\r\n", "Enter Demo dector. method" , i, objName);
(tng) (tng) (tng) }
};
Demo& testMethod0(){
(tng) (tng) (tng) printf("%s\r\n", "Enter testMethod0.");
(tng) (tng) (tng) Demo d(0, "d in testMethod0");
(tng) (tng) (tng) printf("%s\r\n", "Exit testMethod0.");
(tng) (tng) (tng)
return d;
}
Demo testMethod1(){
(tng) (tng) (tng) printf("%s\r\n", "Enter testMethod1.");
(tng) (tng) (tng) Demo d(1, "d in testMethod1");
(tng) (tng) (tng) printf("%s\r\n", "Exit testMethod1.");
(tng) (tng) (tng)
return d;
}
Demo* testMethod2(){
(tng) (tng) (tng) printf("%s\r\n", "Enter testMethod2.");
(tng) (tng) (tng) Demo *d = new Demo(2, "d in testMethod2");
(tng) (tng) (tng) printf("%s\r\n", "Exit testMethod2.");
(tng) (tng) (tng)
return d;
}
int
main(int argc, _TCHAR* argv[])
{
(tng) (tng) (tng) Demo d;
(tng) (tng) (tng) d = testMethod1();
(tng) (tng) (tng) Demo& d1 = testMethod0();
(tng) (tng) (tng) Demo d2(999, "d1");
(tng) (tng) (tng) Demo* d3 = testMethod2();
(tng) (tng) (tng) printf("d.i = %d\r\n", d.i);
(tng) (tng) (tng) printf("d1.i = %d\r\n", d1.i);
(tng) (tng) (tng) printf("d2.i = %d\r\n", d2.i);
(tng) (tng) (tng) printf("d3.i = %d\r\n", d3->i);
(tng) (tng) (tng)
delete d3;
(tng) (tng) (tng)
return 0;
}
Output
Q?/span>
Enter Demo default ctor. method., objName = Default object.
Enter testMethod1.
Enter Demo(int ival) ctor method,i = 1, objName = d in testMethod1
Exit testMethod1.
Enter Demo copy ctor method.
Enter Demo dector. method, i = 1, objName = d in testMethod1
Enter Demo dector. method, i = 1, objName = copied d
Enter testMethod0.
Enter Demo(int ival) ctor method,i = 0, objName = d in testMethod0
Exit testMethod0.
Enter Demo dector. method, i = 0, objName = d in testMethod0
Enter Demo(int ival) ctor method,i = 999, objName = d1
Enter testMethod2
Enter Demo(int ival) ctor method,i = 2, objName = d in testMethod2
Exit testMethod2.
d.i = 1
d1.i = -2
d2.i = 999
d3.i = 2
Enter Demo dector. method, i = 2, objName = d in testMethod2
Enter Demo dector. method, i = 999, objName = d1
Enter Demo dector. method, i = 1, objName = copied d
?/span>
C#
不同Q在
C++
中，对象声明的时候就已经执行?jin)构造函敎ͼ比如上面例子?/span>
main
函数中的W一行，
Demo d
Q从屏幕上的输出来看Q这个时?/span>
Demo class
的默认构造函C(x)被调用?/span>
接下来的一行代码调用，引出?jin)很有趣的情况，当然也隐藏着不小的问题。这行代码造成?jin)一ơ构造函数调用，一ơ拷贝构造函数调用和两次析构函数调用。让我们来具体分析一下：(x)W一ơ调用构造函数很Ҏ(gu)理解Q因为在
testMethod1
中我们声明了(jin)
Demo d(0)
Q退?/span>
testMethod1
Q函数的q回D赋值给变量
d2
Q这个时候，
d2
被拷贝构造函数重新构造了(jin)一ơ。接着
testMethod1
中构造的局部变量被析构Q然后，居然拯构造函数构造的对象也被析构Q等{，看完所有输出，我们发现Q?/span>
objName = copied d
的对象被析构两次Q?/span>
objName = Default obj
的对象被构造出之后没有被析构，q里隐藏?jin)很严重的问题，有可能导致内存泄漏、句柄不能被正确关闭{等。另外，拯构造函数的执行可能D潜在的效率问题，考虑一个包含巨大矩늚对象Q?/span>
copy
q个对象?x)怎么P
接下来的一行代码，
testMethod0
q回一个对象的引用Q当然不?x)导致拷贝构造函数被调用Q但是，q样也是有问题的Q在函数中声明的局部变量在函数执行完成的时候会(x)被析构，那么直接q回局部变量就可能?x)出现问题?/span>
testMethod0
退Z后，他内部的
Demo
对象׃(x)自动析构Q外面对它的引用当然也无法指向正的对象?jin)，所以后面程序打?/span>
d.i
的时候，输出?jin)一个莫名其妙的
-2
?/span>
效率最好的Ҏ(gu)当数q回指针?jin)，它不会(x)导致对象复Ӟ如果使用得当Q也不会(x)D内存泄漏或者句柄泄漏?/span>
testMethod2
演示?jin)这U情况，当然Q你需要手工删除在
testMethod2
中创建的对象?/span>
开发工P(x)
.net 1.1qSharpDevelop
.net 2.0qVS Expresspd
辅助工具有：(x)Reflector?netcd、Snipt Code
java和j2ee用Eclipse+WTP?br />.net framewok SDK、Windows SDK和jdk也都是免费的Q里面也有文档?br />文本比较工具用WinMerge
版本控制Q?br />CVS客户端用Eclipse内置的或者TortoiseCVS
SVN客户端用SVN的Eclipse插g和TortoiseSVN
CVS服务器用CVS NT
SVN服务器用SVN
Debug Release版本或者生产环境的.netE序或者C++E序E序可以用Windbg。SysInternals的一pd工具也是排错利器啊?br />压力试用JMeter和MS Web Stress Tool都还?sh)错?br />查看IE中的Http头可以用ieHttpHeaders
抓取|络包可以用Ethereal
(tng)
文本~辑器：(x)Notepad++、Notepad2 Q如果编辑Python代码Q用Vim更好?br />
览囄qpȝ内置的那个，Picasc2也不错，囄处理可以用MS Paint、Paint.Net或者GIMP?br />
听歌用foobar2000 QW(xu)inamp也是免费的，W(xu)indows Media Player和iTunes虽然比较大，但是功能齐全也算不错的选择?br />压羃解压~用Q?-zip
聊天更多了(jin)Qmsn/qq/gtalk都是免费的。下载用FlashGet和Gigaget?
d列表用的是codeproject上的一个免费工?todolist?制定目计划可以用openworkbench?br />看文一般都是chm的，pdfq是用acrobat reader 7.08
q接Telnet服务器或者SSH服务器可以用putty。FTP、SFTP客户端用WinSCP?br />Mindmap用FreeMind
1.
?/span>
ph
2.
安装
apache
3.
安装
MySQL5
4.
备䆾?/span>
Apache Group\Apache2\conf
”文件夹
5.
?/span>
MySQL
|站下蝲
MySQL Connector/PHP
的文Ӟ下蝲
mysql extension (PH
下面说一下如何配|?/span>
修改 Apache ?/span> httpd.conf 文g
1. (tng) (tng) (tng) (tng) (tng) (tng) 加入 PHPIniDir 变量Q设定加?/span> php5 模块的\径；讑֮ .php 文gcd的处理方式。具体代码如下：(x)
#php config
LoadModule php5_module "d:/php/php5apache2.dll"
AddType application/x-httpd-php .php
PHPIniDir "D:/php/"
2. (tng) (tng) (tng) (tng) (tng) (tng) ?/span> index.php 加入 DirectoryIndex 变量中。具体代码如下：(x)
DirectoryIndex index.html index.html.var index.php
更新 MySQL Connector/PHP
解压 MySQL Connector/PHP 压羃包到 D:\php Qƈ?/span> php_mysql.dll 拯?/span> D:\php\ext
修改
php.ini
1Q?span style="FONT: 7pt 'Times New Roman'"> (tng)
修改 include_path = ".;d:\php\PEAR"2Q?span style="FONT: 7pt 'Times New Roman'"> (tng)
修改 extension_dir = "D:\php\ext"3Q?span style="FONT: 7pt 'Times New Roman'"> (tng)
取消 extension=php_mysql.dll 前面的分?/span>4Q?span style="FONT: 7pt 'Times New Roman'"> (tng)
取消 extension=php_gd2.dll 前面的分?/span>
配置到这里就完成?jin)，Z(jin)试效果Q可以在?/span> Apache Group\Apache2\htdocs ”文件夹中徏立一个名?/span> phpinfo.php 的文Ӟ内容如下Q?/span>
<?php
$link=mysql_connect('localhost','test','test'); //
用户和密?/span>
,
h据你自己的情冉|?/span>
if(!$link) echo "fail";
else echo "success";
mysql_close();
echo phpinfo();
?>
然后讉K http://localhost/phpinfo.php Q如果页面最端上打印出 success Q说明设定成功，否则可以Ҏ(gu) phpinfo 的结果看看问题所在?/span>
(tng)