C/C++/VC MFC char & int study
²âÊÔ´úÂëÒ»£¨VC6.0¡¢C-code£©£º
#include <stdio.h>
void main()
{
int aa;
unsigned char j1,j2;
aa=j1=j2=0;
aa=49;
j1=aa;
printf("j1=%d \n",j1);
j2=aa;
printf("j2=%c \n",j2);
}
¡¾·ÖÎö¡¿£º
[1]ÕýÈçËùÏëÏóµÄÊä³ö½á¹û£º
j1=49
j2=1
Press any key to continue
[2]ÏÈ˵Ã÷aaÔÚÄÚ´æÖеĴ洢ÐÎʽ£º0x0031£»
[3]j1 ,j2ͬΪunsigned charÐÍÊý¾Ý£»
[4]ÉÏÊö¶þ±äÁ¿Êä³ö½á¹û²»Ò»Ö£»ÓÉprinf£¨£©º¯ÊýÖеĸñʽ·û²»Í¬ËùÖ£»
[5]ÕâÀïÈÏΪ£ºÆäÒ»£¬¶ÔÓÚ %d¸ñʽ·û£¬pintf()ÄÜ“ÕýÈ·”·´Ó³ j1 Öд洢µÄÊý¾Ý£»
Æä¶þ£¬¶ÔÓÚ %c¸ñʽ·û£¬printf() È´²»ÄÜ“ÕýÈ·”·´Ó³ j2(==aa)Öд洢µÄ¶þ½øÖÆÊý¾Ý¡£
[6]¶ÔÓÚÒÔÉÏ·ÖÎöµÄÀí½â£ºÏÔÈ»£¬printf()º¯Êý½«»áÒÀÕÕÓû§Ìṩ¸øËüµÄ ¸ñʽ·û ¶Ô´ýÊä³öµÄÊý¾Ý½øÐÐ
“´¦À픺ó£¬Êä³öÖÁÏÔʾÉ豸ÉÏ¡£
[7]……
²âÊÔ´úÂë¶þ(VC6.0 ,VC mfc)£º
int aa,bb;
aa=bb=0;
CString strtemp,display;
strtemp.Format("%c",170); //170==0xAA
MessageBox(strtemp);
int length=strtemp.GetLength();
for(int i=0;i<length;i++)
{
aa+=strtemp.GetAt(i);
bb+=(unsigned char)strtemp.GetAt(i);
}
display.Format("(TCHAR)aa=%x",aa);
MessageBox(display);
display.Format("(unsigned char)bb=%x",bb);
MessageBox(display);
¡¾·ÖÎö¡¿£º
[1]Êä³öÇåµ¥ÈçÏ£º
MessageBox(strtemp);===== "?"
display.Format("(TCHAR)aa=%x",aa);
MessageBox(display);====="(TCHAR)aa=ffffffaa" //(ff ff ff aa)
display.Format("(unsigned char)bb=%x",bb);
MessageBox(display);====="("(unsigned char)bb=aa"
[2] // return single character at zero-based index
TCHAR GetAt(int nIndex) const;
<À´Ô´£ºCString-class£»×îÖÕ½âÊÍΪmicrosoft VC6.0>
[3]typedef char TCHAR, *PT
Ïà¹ØÎĵµ£º
#include <iostream>
using namespace std;
class Base {
public:
virtual void fn(int x) {
cout << "In Base class, int x = " << x << endl;
}
};
class SubClass : public Base {
public:
// º¯ÊýµÄÖØÔØ,ÕâÑùµÄÖØÔØ·½Ê½,ÔÚJavaÖÐÄÜÐÐ,ÔÚC/C++ÖÐÈ´²»ÐÐ
virt ......
ÌâÄ¿£ºÔÚÆÁÄ»Éϻһ¸ö¾ØÐÎ
ÒªÇó£ºÃ¿°´Ò»´Î¼üÅÌ£¬¸Ã¾ØÐÎת¶¯45¶È¡£¾ØÐεĴóСºÍת¶¯µÄ·½ÏòÓмüÅÌÊäÈ룬²¢½«ÊäÈëµÄÊý¾ÝËÍÎļþ±£´æ£¬°´»Ø³µ¼ü³ÌÐò½áÊø¡££¨¹¦ÄÜÑÓÉ죺¸Ä±äÊý¾ÝÎļþµÄÄÚÈݺó£¬ÔÙ¸ù¾ÝÊý¾ÝÎļþÀïµÄÊý¾Ý»æÖƾØÐΣ©
......
ÔÀ´ÊDZ»µ÷ÓõÄdllÓÖµ÷ÓÃÁËÆäËûµÄdll
µÚ¶þ¸ödllÍü¼ÇÁË¿¼µ½¹¤×÷Ŀ¼ÏÂ
µ¼ÖÂÁËc sharpһֱûÄܼÓÔØdll¡£±¨´í£ºÕÒ²»µ½dll
ÏÖÔÚÏëÆðÀ´£¬ËùνµÄdllÕÒ²»µ½£¬Ó¦¸ÃÊÇÕÒ²»µ½µÚ¶þ¸ödll
ÏûºÄʱ¼ä2¸öСʱ£¬ÐÄÇéÉÔ΢ÓеãÊÜÓ°Ïì ......
LinuxϽøÐÐMYSQLµÄC++±à³ÌÆð²½ÊÖ¼Ç
Ê×ÏȰ²×°±ØÐèµÄ¿ª·¢°ü
sudo apt-get install gcc g++ libgcc1 libg++ make gdb
°²×°MYSQLµÄCÓïÑÔ¿ª·¢°ü
sudo apt-get install libmysql++-dev libmysql++2c2a libmysqlclient15-dev libmysqlclient15off
......
C/S¼Ü¹¹µÄÓŵãÈçÏ£º
£¨1£©C/S¼Ü¹¹µÄ½çÃæºÍ²Ù×÷ÊÖÊÆ¿ÉÒÔËæ×ſͻ§µÄÒªÇó½øÐж¨ÖÆ£¬¿ÉÒÔʵÏֵķdz£Æ¯ÁÁ£¬ÓÉÓÚÅÖ¿Í»§¶Ë½¨Á¢ÔÚÓ¦ÓõĻù´¡ÉÏ£¬Òò´Ë²»»áÓÉÓÚÆ¯ÁÁµÄ½çÃæ¶øÓ°Ïìʵ¼ÊµÄ²Ù×÷¡£
£¨2£©ÏµÍ³°²È«ÐÔÄÜ¿ÉÒԵõ½ºÜºÃµÄ±£Ö¤£¬ÊµÏÖ¶à²ãÈÏÖ¤Ò²²»À§ÄÑ¡£
£¨3£©C/S½á¹¹µÄϵͳÓÉÓÚÖ»ÓÐÒ»²ã½»»¥£¬Òò´ËÏìÓ¦Ëٶȷdz£¿ì¡£
C/S¹¹¼ÜµÄÈ ......