Tuesday, December 30, 2008

Unicode and RichEditCtrl

[source]

Unicode and RichEditCtrl
Unicode Strings in MFC
The easiest way to deal with Unicode strings is to use CStringW class. As it is, CStringW can edit Unicode strings. Another option is to use char* equivalent wide-byte type in MFC called LPWSTR.

Writing and reading Unicode strings to and from controls in MFC is not exactly as straight forward. GetDlgItemText and SetDlgItemText only take single byte character strings. This page explains how to send messages to set and retrieve Unicode strings to the controls without the use of those functions.

Take a look at the following functions. Those functions read and write Unicode strings from and to MFC controls (RichEditCtrl). Sending messages requires several steps. First is to specify the type of the message. The type of the message, the codepage, and other optional settings are set to a structure called GETTEXTEX and SETTEXTEX. Then calculate and prepare space to store the results.

LPWSTR GetUnicodeString(UINT id)
{
CRichEditCtrl* edit=(CRichEditCtrl*)GetDlgItem(id);
int nLength = edit->GetTextLengthEx(GTL_DEFAULT,1200);
LPWSTR lpszWChar = new WCHAR[nLength+1];

GETTEXTEX getTextEx;
getTextEx.cb=(nLength+1)*sizeof(WCHAR);
getTextEx.codepage=1200;
getTextEx.flags=GT_DEFAULT;
getTextEx.lpDefaultChar=NULL;
getTextEx.lpUsedDefChar=NULL;

edit->SendMessage(EM_GETTEXTEX, (WPARAM)&getTextEx, (LPARAM)lpszWChar);

return lpszWChar;
}

void SetUnicodeString(UINT id, LPWSTR str)
{
SETTEXTEX setTextEx;
setTextEx.codepage=1200;
setTextEx.flags=ST_DEFAULT;

CRichEditCtrl *caption=(CRichEditCtrl*)GetDlgItem(id);
if(caption!=NULL)
caption->SendMessage(EM_SETTEXTEX, (WPARAM)&setTextEx, (LPARAM)str);
}




The usage of GetUnicodeString above is shown below. Specify the ID of the RichEditCtrl control.

CStringW str=GetUnicodeString(IDC_RICHEDITCTRL);


Likewise, the usage of SetUnicodeString above is shown below. Specify the ID of the RichEditCtrl control, and the Unicode string to be set to the control.

SetUnicodeString(IDC_RICHEDITCTRL,str);

Monday, December 15, 2008

C Restrict Pointers

[Source]

One of the new features in the recently approved C standard C99, is the restrict pointer qualifier. This qualifier can be applied to a data pointer to indicate that, during the scope of that pointer declaration, all data accessed through it will be accessed only through that pointer but not through any other pointer. The 'restrict' keyword thus enables the compiler to perform certain optimizations based on the premise that a given object cannot be changed through another pointer. Now you're probably asking yourself, "doesn't const already guarantee that?" No, it doesn't. The qualifier const ensures that a variable cannot be changed through a particular pointer. However, it's still possible to change the variable through a different pointer. For example:



void f (const int* pci, int *pi;); // is *pci immutable?
{
(*pi)+=1; // not necessarily: n is incremented by 1
*pi = (*pci) + 2; // n is incremented by 2
}
int n;
f( &n, &n);


In this example, both pci and pi point to the same variable, n. You can't change n's value through pci but you can change it using pi. Therefore, the compiler isn't allowed to optimize memory access for *pci by preloading n's value. In this example, the compiler indeed shouldn't preload n because its value changes three times during the execution of f(). However, there are situations in which a variable is accessed only through a single pointer. For example:



FILE *fopen(const char * filename, const char * mode);

The name of the file and its open mode are accessed through unique pointers in fopen(). Therefore, it's possible to preload the values to which the pointers are bound. Indeed, the C99 standard revised the prototype of the function fopen() to the following:


/* new declaration of fopen() in */
FILE *fopen(const char * restrict filename,
const char * restrict mode);

Similar changes were applied to the entire standard C library: printf(), strcpy() and many other functions now take restrict pointers:


int printf(const char * restrict format, ...);
char *strcpy(char * restrict s1, const char * restrict s2);

C++ doesn't support restrict yet. However, since many C++ compilers are also C compilers, it's likely that this feature will be added to most C++ compilers too.

Danny Kalev

Friday, December 05, 2008

WinXP FAT32 與 NTFS 之間的轉換

[FAT32 -> NTFS]
保留資料
1) > convert D:/FS:NTFS /V
2) Partition Magic

不保留資料
> format D:/FS:NTFS

[NTFS -> FAT32]
保留資料
Partition Magic

不保留資料
> format D:/FS:FAT32

Wednesday, December 03, 2008

POSIX Threads Programming

https://computing.llnl.gov/tutorials/pthreads/

Books:
- Programming with POSIX Threads
- Multithreading Programming Techniques
- Getting Started With POSIX Threads

Saturday, July 05, 2008

Set Environment Variables for VC

If we install more than 1 version of VC compilers, it's better to set environment variable to the version that we'd like to use for compiling programs under command mode (e.g. use nmake with makefile):

VC6:
$(VS_Path)\VC98\Bin\vcvars32.bat

VC7 (2003) / VC8 (2005) / VC9 (2008):
$(VS_Path)\Common7\Tools\vsvars32.bat

Sunday, March 02, 2008

精通 vi - Chap 3 快速移動位置

1. 移動
往下捲動一個螢幕 ^F
往上捲動一個螢幕 ^B
往下捲動半個螢幕 ^D
往上捲動半個螢幕 ^U
往下捲動一行 ^E
往上捲動一行 ^Y

將本行移到螢幕頂端 z [Enter]
將本行移到螢幕中間 z.
將本行移到螢幕最後 z-

移到螢幕頂端 H
移到螢幕中間 M
移到螢幕最後 L
移到下一行首 + 或 [Enter]
移到上一行首 -

移到句子開頭 (
移到下一句子開頭 )
移到段落開頭 {
移到下一段落開頭 }

到第 n 行 nG
到最後一行 G

2. 搜尋
向下找 /pattern
向上找 ?pattern
同一方向重複找 n
相反方向重複找 N

重複上一搜尋命令,方向相同 ;
重複上一搜尋命令,方向相反 ,

3. 其它
估計目前所在位置的百分比 ^G

精通 vi - Chap 2 簡單的文字編輯

1. 編輯命令
文字物件 更改 刪除 複製
一個單字 cw dw yw
兩個單字,不含標點 2cW 2dW 2yW
往回三個單字 3cb 3db 3yb
一整行 cc dd yy
到一行末 c$ d$ y$
到一行首 c0 d0 y0
單一字元 r x y1
五個字元 5s 5x 5y1

貼上 p 或 P

2. 游標移動
左下上右 h, j, k, l
到下一行首 +
到上一行首 -
到單字結尾 e
往後一個單字 w
往前一個單字 b
到本行末 $
到本行首 0

3. 建立與處理文字
在游標所在位置插入文字 i
在行首插入文字 I
在游標所在位置附加文字 a
在行尾附加文字 A
在游標下一行開啟新行 o
在游標上一行開啟新行 O
刪除一行並代換文字 S
用新文字覆蓋現存的文字 R
合併此行與下一行 J
切換大小寫 ~
重複上一動作 .
還原上一動作 u
還原一整行的編輯 U

精通 vi - Chap 1 vi 文字編輯器

開檔
> vi [filename]

儲存
:w
:w [new filename] (另存新檔)
:w! (強迫寫入)
:w! [filename] (強迫寫入或蓋掉另一檔案)

結束並儲存
ZZ

消除編輯結果,回到原檔案
:e!

結束但不儲存
:q!

精通 vi

精通 vi (Learning the vi Editor)
Linda Lamb & Arnold Robbins 原著, Nov 1998
林逸文 譯, Mar 2000
O'REILLY

Thursday, February 21, 2008

INIT: Id "co" respawning too fast: disabled for 5 minutes

Solve the problem, or disable it in /etc/inittab.

ADSL on Linux

1) Prepare your ISP login name and password.
2) Setup the rpm of PPPOE if it's necessary.
3) Setup configuration.
> adsl-setup

4) To start ADSL:
> /sbin/ifup ppp0

5) To stop ADSL:
> /sbin/ifdown ppp0