{DELPHI OBJECT PASCAL 语法精要样例}

//***********************************************************************

//此文本以样例的形式介绍了常用的DELPHI OBJECT PASCAL语法、数据类型

//以及一些使用规范。希望对大家有用并提出宝贵意见。

//************************************************************************

//******************************************************************

//主程序规范和语法

Program



Ueses useunit1,useunit2;



Begin



End.



//**********************************************************************

//unit 单元规范和语法



Unit name

//定义部分

Interface 

//单元引用

Uses unitname1,unitname2;

//条件编译预定义

{$DEFINE DEFTEST1}

{$IFDEF DEFTEST}

…….

{$ELSE}

……..

{$ENDIF}

//包含预编译指令

{$I INCLUDEFILE.INC}



//数据类型

{

Type	    Range				Format

Shortint	-128..127	   			signed 8-bit

Smallint	-32768..32767			signed 16-bit

Longint	-2147483648..2147483647	signed 32-bit

Int64		-2^63..2^63-1				signed 64-bit

Byte		0..255				unsigned 8-bit

Word		0..65535				unsigned 16-bit

Longword	0..4294967295		unsigned 32-bit

Pointer							指针unsigned 32-bit

Boolean						bool类型

Char                          字符类型



浮点类型

Type		Range							Significant digits			Size in bytes

Real48		2.9 x 10^-39 .. 1.7 x 10^38			11-12					6

Single		1.5 x 10^-45 .. 3.4 x 10^38			7-8						4

Double	5.0 x 10^-324 .. 1.7 x 10^308			15-16					8

Extended	3.6 x 10^-4951 .. 1.1 x 10^4932		19-20					10

Comp		-2^63+1 .. 2^63 -1					19-20					8

Currency	-922337203685477.5808.. 922337203685477.5807	19-20		8



字符串类型

Type			Maximum length				Memory required

ShortString		255 characters					2 to 256 bytes	

AnsiString		~2^31 characters				4 bytes to 2GB	

WideString		~2^30 characters				4 bytes to 2GB	

}

//全局变量

Var 

giInt : integer;

//数组

gArray : array[0..10] as integer;

//全局常量

Const

  giInt = 1234;

//类型定义

Type

  //记录定义

  Trecodr = record

    iInt : integer;

    pPointer : pointer;

    //记录联合

    Case integer of

    0 : (wWord : word;

       wWord2 : word);

    1 : (dDword : Dword);

   End;

   //自定义数据类型

   TselfData = (tdself1,tdself2,tdself3t,tdself4);

   //自定义枚举类型

   TsetSelfData = set of TselfData;

   //函数指针和事件函数定义

   TselfOnChanged = procedure (sender : tobject;tagid,id : integer)of object;

  //类定义

  TselfClass = class(Tobject)

  Private //私有函数和变量

    FiInt : integer;

    Function selffunc(par1 : word;ppar : pointer) : integer;

    //message 映射

    Procedure WMMessage(var msg : Tmessage); message WM_MESSAGE;

    //属性存取函数

    Function GetiINt : integer;

    Procedure SetiInt(value : integer);

  Protected //保护函数和变量，允许类继承者访问。

    Function selfoverride(ppar : pointer) : dword;override;//类函数继承

    //类函数重载，同样适用用于不同函数。

    Procedure selfoverload(ppar : pointer);overload;

    Procedure selfoverload(ppar : pointer;iindex : integer);overload; 

  Public //共有函数和变量，允许所有人访问

    //构造函数

    Constructor create(sender : Tobject);override;

    //析构函数

    Destructor destroy;override;

    //’属性定义

    Property selfpro : integer read FiInt Write FiInt;

    Property selfprofunc : integer read GetiInt Write SetiInt;//使用函数存取属性

//数组属性定义，自读属性，类默认属性

    property items[index : integer] : integer Read GetItems;default;

  end;



//全局函数定义

Function gfunc(iIndex : integer) : word;stdcall;//stdcall定义参数调用方法，如果是dll，必须使用



//----------------------------------------------------------------------------------------------------------

//程序实现

Implementation



//引用

Uses useunit1;



//在delphi空间栏注册函数

procedure Register;

begin

RegisterComponents('WISDOSOFT',[TselfControl1,Tselfcontrol2]);

End

//类函数实现

Function TselfClass.GetiInt : integer;

Begin

  Result := FiInt;

  ….

End;

//构造函数实现

Constructor TselfClass.create(sender : Tobject);

Begin

 inherited create(sender);//函数继承

 ….

End;

……

//函数实现以及语法简介

Function gFunc(iIndex : integer) : word;

Var//变量定义

 iCount : integer;

const//常量定义

 MAX_COUNT = 200；

 CONST_STR = ‘THIS ONLY TO TEST’;

Begin

 //FOR 循环

 FOR iCount = 0 to MAX_COUNT DO 

 Begin

 …..

 End;

 //for 递减循环

 For iCount = MAX_COUNT downto 0 do

 Begin

  …..

 End;

 //while 循环

 While iCount > 0 do 

 Begin

  iCount := iCount – 1;

  …..

 End;

 //until 循环

 Repeat

  iCount := iCount + 1;

  ….

  Until iCount > MAX_COUNT;

 //if 语句

 If iCount > 0 then 

 Begin

 ….

 End else if iCount = 0 then 

 Begin

  ….

 End else Begin

  ….

 End;

 

End;



//单元初始运行

initialization

  CreateSysImages;



//单元对初始运行

finalization

  DestroySysImages;



End.//单元结束



//***************************************************************************

//dll编写规范

library FileBackDll;



{ Important note about DLL memory management: ShareMem must be the

  first unit in your library's USES clause AND your project's (select

  Project-View Source) USES clause if your DLL exports any procedures or

  functions that pass strings as parameters or function results. This

  applies to all strings passed to and from your DLL--even those that

  are nested in records and classes. ShareMem is the interface unit to

  the BORLNDMM.DLL shared memory manager, which must be deployed along

  with your DLL. To avoid using BORLNDMM.DLL, pass string information

  using PChar or ShortString parameters. }



uses

  SysUtils,

  Classes;

//函数定义

  function dllStartBackup(hwin : Thandle;pData : PRFCBackUpData):boolean;stdcall;



//dll输出函数定义

exports



  DllStartBackUp index 1;



begin

 //函数实现

 function dllStartBackup(hwin : Thandle;pData : PRFCBackUpData):boolean;

begin

 ……

end;

end.

//****************************************************************

//dll函数引用使用方法

Unit dllunit;



Uses 



function MoveFile(lpExistingFileName, lpNewFileName: PChar): BOOL; stdcall;



Implementation



function MoveFile; external ‘kernel32’ name 'MoveFileA';



end.