Delphi 之运算符重载

最新推荐文章于 2024-08-11 22:34:41 发布

转载最新推荐文章于 2024-08-11 22:34:41 发布 · 1k 阅读

文章标签：

#delphi #button #class #forms #windows #div

编程技术专栏收录该内容

6 篇文章

订阅专栏

本文介绍Delphi7及以后版本中引入的运算符重载功能，通过实例展示了如何为自定义类型实现加法运算符，并列出了Delphi支持的所有运算符重载及其对应的英文标识。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Delphi 7之后的版本，增加了运算符的重载。虽然不尽人意（需要写特定英文），但有总比没有强。

例：

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
T3DPoint = record
X, Y, Z: Double;
class operator ADD(ALeftPoint, ARightPoint: T3DPoint): T3DPoint; {重载'+'运算符}
end;

TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
private
    { Private declarations }
public
    { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

{ T3DPoint }

class operator T3DPoint.ADD(ALeftPoint, ARightPoint: T3DPoint): T3DPoint;
begin
Result.X := ALeftPoint.X + ARightPoint.X;
Result.Y := ALeftPoint.Y + ARightPoint.Y;
Result.Z := ALeftPoint.Z + ARightPoint.Z;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
A, B, Z: T3DPoint;
begin
A.X := 1; A.Y := 1; A.Z := 1;
B.X := 3; B.Y := 3; B.Z := 3;
Z := A + B;

ShowMessageFmt('%f, %f, %f', [Z.X, Z.Y, Z.Z]); {4.00, 4.00, 4.00}
//ShowMessage(FloatToStr(Z.X) + ',' + FloatToStr(Z.Y) + ',' + FloatToStr(Z.Z)); {4, 4, 4}
end;

end.

下面附上所有的运算符:

重载特定英文行为（或目数）方法操作符

Implicit	Conversion	Implicit(a : type) : resultType; (封箱)	implicit typecast
Explicit	Conversion	Explicit(a: type) : resultType; (拆箱)	explicit typecast
Negative	Unary	Negative(a: type) : resultType;	-
Positive	Unary	Positive(a: type): resultType;	+
Inc	Unary	Inc(a: type) : resultType;	Inc
Dec	Unary	Dec(a: type): resultType	Dec
LogicalNot	Unary	LogicalNot(a: type): resultType;	not
BitwiseNot	Unary	BitwiseNot(a: type): resultType;	not
Trunc	Unary	Trunc(a: type): resultType;	Trunc
Round	Unary	Round(a: type): resultType;	Round
Equal	Comparison	Equal(a: type; b: type) : Boolean;	=
NotEqual	Comparison	NotEqual(a: type; b: type): Boolean;	<>
GreaterThan	Comparison	GreaterThan(a: type; b: type) Boolean;	>
GreaterThanOrEqual	Comparison	GreaterThanOrEqual(a: type; b: type): resultType;	>=
LessThan	Comparison	LessThan(a: type; b: type): resultType;	<
LessThanOrEqual	Comparison	LessThanOrEqual(a: type; b: type): resultType;	<=
Add	Binary	Add(a: type; b: type): resultType;	+
Subtract	Binary	Subtract(a: type; b: type) : resultType;	-
Multiply	Binary	Multiply(a: type; b: type) : resultType;	*
Divide	Binary	Divide(a: type; b: type) : resultType;	/
IntDivide	Binary	IntDivide(a: type; b: type): resultType;	div
Modulus	Binary	Modulus(a: type; b: type): resultType;	mod
LeftShift	Binary	LeftShift(a: type; b: type): resultType;	shl
RightShift	Binary	RightShift(a: type; b: type): resultType;	shr
LogicalAnd	Binary	LogicalAnd(a: type; b: type): resultType;	and
LogicalOr	Binary	LogicalOr(a: type; b: type): resultType;	or
LogicalXor	Binary	LogicalXor(a: type; b: type): resultType;	xor
BitwiseAnd	Binary	BitwiseAnd(a: type; b: type): resultType;	and
BitwiseOr	Binary	BitwiseOr(a: type; b: type): resultType;	or
BitwiseXor	Binary	BitwiseXor(a: type; b: type): resultType;	xor