01 02 first windows program

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FIRST WINDOWS PROGRAM

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A CHARACTER-MODE MODEL

Basic version of C (Old version)

#include

{

printf ("hello, world\n") ;

}

ANSI version of C(or ANSI C)

#include

int main ()

{

printf ("hello, world\n") ;return 0 ;

}

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THE WINDOWS EQUIVALENT

#include

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE

hPrevInstance, PSTR szCmdLine, int iCmdShow)

{

MessageBox (NULL, TEXT ("Hello, Welcome to Windows

Programming!"), TEXT ("HelloMsg"), 0) ;

return 0 ;

}

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THEMECHANICSOFCREATINGAPROGRAMINTHE

VISUAL C++ DEVELOPER STUDIO.

To begin,

select New from the File menu. In the New dialog box, pick the Projects tab. Select Win32 Application. In the

Location field, select a subdirectory.

In the Project Name field, type the name of the project, which in this case isHelloMsg.This will be a subdirectory of the directory indicated in the

Location field. The Create New Workspace button should be checked. The Platforms section

should indicate Win32. Choose OK.

A dialog box labeled Win32 Application - Step 1 Of 1 will appear.

Indicate that you want to create an Empty Proj ect, and press the Finishbutton.

Select New from the File menu again. In the New dialog box, pick the Files tab. Select C++ Source File.

The Add To Project box should be checked, and HelloMsg should beindicated.

Type HelloMsg.c in the File Name field.

Choose OK. 4


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STRUCTURALLY, HELLOMSG.C ISIDENTICALTOTHE

ANSI C "HELLO, WORLD" PROGRAM.

The header file STDIO.H has been replaced with

WINDOWS.H,

the entry point main has been replaced withWinMain, and

the C run-time library function printf has been

replaced with the Windows API function MessageBox.

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THE HEADER FILES

#include

WINDOWS.H is a master include file that includes otherWindows header files, some of which also include other headerfiles. The most important and most basic of these header filesare:

windef.hBasic type definitions.

winnt.hType definitions for Unicode support.

winbase.h Kernel functions.

winuser.hUser interface functions.

wingdi.hGraphics device interface functions.

These header files define all the Windows data types, functioncalls, data structures, and constant identifiers. They are animportant part of Windows documentation. 6


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PROGRAM ENTRY POINT

Just as the entry point to a C program is the function

main, the entry point to a Windows program is

WinMain, which always appears like this:

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int WinMain (HINSTANCE hInstance, HINSTANCEhPrevInstance, PSTR szCmdLine, int iCmdShow)

Or

int

WINAPI

WinMain(

HINSTANCE hInstance,

HINSTANCE hPrevInstance, LPSTR lpCmdLine,

int nShowCmd

);


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PROGRAM ENTRY POINT

The LP prefix stands for "long pointer" and is an artifactof 16-bit Windows.

The WinMainfunction is declared as returning an int.

The four parameters are:

hInstance is something called a "handle to an instance"or "handle to a module."

The operating system uses this value to identify the executable(EXE) when it is loaded in memory.

The instance handle is needed for certain Windows functions

For example, to load icons or bitmaps. 8


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PROGRAM ENTRY POINT

hPrevInstancehas no meaning. It was used in 16-bit

Windows, but is now alwayszero.

pCmdLinecontains the command-line arguments asa Unicode string.

nCmdShowis a flag that says whether the main

application window will be minimized, maximized,orshown normally.

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THEMESSAGEBOXFUNCTION

The MessageBoxfunction is designed to display short

messages.

The little window thatMessageBoxdisplays is actuallyconsidered to be a dialog box, although not one with a

lot of versatility.

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The first argument to MessageBoxis normally a window

handle.

The second argument is the text string that appears in

the body of the message box, and

the third argument is the text string that appears in the

caption bar of the message box.

In HELLMSG.C, each of these text strings is enclosed in a TEXTmacro.

You don't normally have to enclose all character strings in the

TEXT macro, but it's a good idea if you want to be ready to

convert your programs to the Unicode character set. 11


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The fourth argument to MessageBox can be a combination of

constants beginning with the prefix MB_ that are defined in

WINUSER.H.

You can pick one constant from the first set to indicate what

buttons you wish to appear in the dialog box:

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BUTTUN TYPE CONSTANT VALUES

OK MB_OK 0x00000000L

OK + CANCEL MB_OKCANCEL 0x00000001L

ABORT + RETRY + IGNORE MB_ABORTRETRYIGNORE 0x00000002L

YES+NO+CANCEL MB_YESNOCANCEL 0x00000003L

YES+NO MB_YESNO 0x00000004L

RETRY+CANCEL MB_RETRYCANCEL 0x00000005L


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You can also use a constant that indicates the

appearance of an icon in the message box:

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BUTTUN TYPE CONSTANT VALUES

MB_ICONHAND 0x00000010L

MB_ICONQUESTION 0x00000020L

MB_ICONEXCLAMATION 0x00000030L

MB_ICONASTERISK 0x00000040L

MB_ICONWARNING MB_ICONEXCLAMATION

MB_ICONERROR MB_I CONHAND

MB_ICONINFORMATION MB_ICONASTERISK

MB_ICONSTOP MB_I CONHAND


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COMPILE, LINK, AND RUN

When you're ready to compile the program, you can

select Build program.exe from the Build menu, or

press F7, or select the Build icon from the Build

toolbar.

Alternatively, you can select Execute program.exe

from the Build menu, or press Ctrl+F5, or click the

Execute Program icon (which looks like a red

exclamation point) from the Build toolbar. You'll get amessage box asking you if you want to build the

program.14


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AN INTRODUCTIONTO UNICODE

Unicode is an extension of ASCII character encoding.

Rather than the 7 bits used to represent each character instrictASCII, or the 8 bits per character that have becomecommon on computers, Unicode uses a full16 bits for

character encoding.

This allows Unicode to represent all the letters,ideographs, and other symbols used in all the writtenlanguages of the world that are likely to be used in

computer communication.

Unicode impacts every part of the computer industry, butperhaps most profoundly operating systems andprogramming languages. 15


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A BRIEF HISTORYOF CHARACTER SETS

It is uncertain when human beings began speaking, butwriting seems to be aboutsix thousand years old.

Early writing was pictographic in nature. Alphabets in whichindividual letters correspond to spoken sounds came about justthree thousand years ago.

Although the various written languages of the world served finefor some time, several nineteenth-century inventors saw a needfor something more.

When Samuel F. B. Morse developed the telegraph

between 1838 and 1854, he also devised a code to usewith it. Each letter in the alphabet corresponded to aseries of short and long pulses (dots and dashes).

There was no distinction between uppercase and lowercaseletters, but numbers and punctuation marks had their owncodes.

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A BRIEF HISTORYOF CHARACTER SETS

Morse code was not the first instance of written languagebeing represented by something other than drawn orprintedglyphs.

Between 1821 and 1824, the young Louis Braille was

inspired by a military system for writing and readingmessages at night to develop a code for embossing raiseddots into paper for reading by the blind. Braille is essentially a 6-bit code that encodes letters, common

letter combinations, common words, and punctuation.

A special escape code indicates that the following lettercode is to be interpreted as uppercase. A special shift codeallows subsequent letter codes to be interpreted asnumbers.

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AMERICAN STANDARDS

Early computer character codes evolved from the codingused on Hollerith ("do not fold, spindle, or mutilate")cards, invented by Herman Hollerith and first used in the1890 United States census.

A 6-bit character code known as BCDIC ("Binary-CodedDecimal Interchange Code") based on Hollerith coding wasprogressively extended to the 8-bit EBCDIC in the 1 960s andremains the standard on IBM mainframes but nowhere else.

Note: A punched card / punch card / IBM card, orHollerith card is a piece ofstiff paper that contains digitalinformation represented by the presence or absence ofholes in predefined positions.

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AMERICAN STANDARDS ASCII

The American Standard Code for InformationInterchange (ASCII) had its origins in the late 1 950s andwas finalized in 1967. Reliability considerations seemed to mandate that no shift

character be used, so ASCII couldn't be a 6-bit code. Cost ruledout the 8-bit version. (Bits were very expensive back then.)

The final code had 26 lowercase letters,

26 uppercase letters,

10 digits,

32 symbols, 33 control codes, and

a space,

for a total of 128 codes.

it appears in theANSI document. 19


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ASCII

It is a character-encoding scheme.

Originally based on the English alphabet.

ASCII codes represent text in computers,

communications equipment, and other devices that

use text.

Most modern character-encoding schemes are based

on ASCII, though they support many more characters

than ASCII does. 20
http://../Imgs/ASCII_Code_Chart.svg.pnghttp://../Imgs/ASCII_Code_Chart.svg.png


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ASCII

All 128 ASCII characters, including non-printable

characters (represented by their abbreviations). The 95 ASCII graphic characters are numbered from

20hex to 7Ehex (decimal 32 to 126). The space

character is considered a non-printing graphic. 21
http://../Imgs/ASCII_Code_Chart.svg.pnghttp://../Imgs/ASCII_Code_Chart.svg.png

01 02 first windows program

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