Example of DELPHI8 operator overloading

unit WinForm;


Interface


uses


System.Drawing, System.Collections, System.ComponentModel,


System.Windows.Forms, System.Data;


type


Twinform = Class (System.Windows.Forms.Form)


{$REGION ' Designer Managed Code '}


Strict Private


///<summary>


///Required designer variable.


///</summary>


Components:System.ComponentModel.Container;


Button1:System.Windows.Forms.Button;


///<summary>


///Required to Designer support-do not modify


///The contents of this method with the Code editor.


///</summary>


procedure InitializeComponent;


procedure button1_click (sender:System.Object; e:system.eventargs);


{$ENDREGION}


Strict protected


///<summary>


///clean up any being used.


///</summary>


procedure Dispose (Disposing:boolean); Override


Private


{Private Declarations}


Public


constructor Create;


end;


//Written class is OK, I use the record here. Because logging is a value type eliminates the hassle of creating an instance


Tclasstest=record


Public


Fa:integer;


//overloaded "+" operator


class operator Add (a,b:tclasstest): tclasstest;


end;


[Assembly:runtimerequiredattribute (TypeOf (Twinform))]


Implementation


{$REGION ' Windows Form Designer generated code '}


///<summary>


///Required method for Designer support-does not modify


///The contents of this method with the Code editor.


///</summary>


procedure twinform.initializecomponent;


begin


Self.button1: = System.Windows.Forms.Button.Create;


self.suspendlayout;


　//


//Button1


　//


Self.Button1.Location: = System.Drawing.Point.Create (96, 88);


Self.Button1.Name: = ' Button1 ';


Self.Button1.Size: = System.Drawing.Size.Create (392, 112);


Self.Button1.TabIndex: = 0;


Self.Button1.Text: = ' Button1 ';


Include (Self.Button1.Click, Self.button1_click);


　//


//Twinform


　//


self.autoscalebasesize: = System.Drawing.Size.Create (6, 14);


self.clientsize: = System.Drawing.Size.Create (560, 357);


Self.Controls.Add (Self.button1);


self.name: = ' twinform ';


self.text: = ' WinForm ';


self.resumelayout (False);


End


{$ENDREGION}


procedure Twinform.dispose (Disposing:boolean);


begin


if disposing then


begin


If components <> nil then


Components.dispose ();


end;


inherited Dispose (disposing);


end;


constructor Twinform.create;


begin


inherited Create;


　//


//Required for Windows Form Designer support


　//


InitializeComponent;


　//


//Todo:add Any constructor code after InitializeComponent call


　//


end;


procedure Twinform.button1_click (sender:System.Object; e:system.eventargs);


var


a,b,c:tclasstest;


begin


A.FA: = 1;


B.FA: = 2;


c:=a+b; Two structures (or classes) with + operation, before DELHI8 is unthinkable


System. Windows.Forms.MessageBox.Show (System.Convert.ToString (C.FA));


end;


{tclasstest}


//overload "+" operator implementation


class operator Tclasstest.add (A, b:tclasstest): tclasstest;


begin


Result.fa:=a.fa + b.fa;


end;


end.