unit SenderUnit;

interface

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

type
  TSenderForm = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private 宣言 }
  public
    { Public 宣言 }
  end;

var
  SenderForm: TSenderForm;

implementation

{$R *.DFM}

//=============================================================================
//  Button1をクリックするとID値が1000のコントロールに文字列をセットする
//=============================================================================
procedure TSenderForm.Button1Click(Sender: TObject);
var
  hWindow   : HWND;
  RevHandle : HWND;
  Str       : String;
begin
  //受取る側のアプリのウィンドウハンドル
  hWindow := FindWindow('TReceivForm', nil);

  if hWindow <> 0 then begin
    //hWindowのID値が1000の子ウィンドウのハンドル
    RevHandle := GetDlgItem (hWindow, 1000);

    //そこにEdit1.Textを送る
    SendMessage(RevHandle, WM_SETTEXT, 0, LPARAM(PChar(Edit1.Text)));

    //hWindowのID値が1100の子ウィンドウのハンドル
    RevHandle := GetDlgItem (hWindow, 1100);

    //そこに文字列を送る
    Str := Edit1.Text + sLineBreak + Edit1.Text;
    SendMessage(RevHandle, WM_SETTEXT, 0, LPARAM(PChar(Str)));
  end;
end;

end.

unit ReceiverUnit;

interface

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

type
  TReceivForm = class(TForm)
    Edit1: TEdit;
    Memo1: TMemo;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private 宣言 }
  public
    { Public 宣言 }
  end;

var
  ReceivForm: TReceivForm;

implementation

{$R *.DFM}

//=============================================================================
//  他のアプリから操作しやすいように、各EditのID値を変更しておく
//=============================================================================
procedure TReceivForm.FormCreate(Sender: TObject);
begin
  SetWindowLong(Edit1.Handle, GWL_ID, 1000);
  SetWindowLong(Memo1.Handle, GWL_ID, 1100);
end;

//=============================================================================
//  テキストをクリア
//=============================================================================
procedure TReceivForm.Button1Click(Sender: TObject);
begin
  Edit1.Clear;
  Memo1.Clear;
end;

end.