{----------------------------------------
WMCOPYDATAメッセージの送信受信のユニット
2012/10/11(木)
・	作成



◇実装例：

type
  TForm1 = class(TForm)
  private
    FWMCopyDataConnection: TWMCopyDataConnection;
    procedure WMCopyData(var msg: TWMCopyData); message WM_COPYDATA;
  end;


const SIGNATURE_STRING: DWORD = $00000001;

procedure TForm1.FormCreate(Sender: TObject);
begin
  FWMCopyDataConnection := TWMCopyDataConnection.Create;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FWMCopyDataConnection.Free;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  FWMCopyDataConnection.SendText(Self.Handle, SIGNATURE_STRING, Memo1.Text);
end;

procedure TForm1.WMCopyData(var msg: TWMCopyData);
var
  ReceiveText: String;
begin
  if FWMCopyDataConnection.ReceiveText(msg, SIGNATURE_STRING, ReceiveText) then
  begin
    Memo2.Text := ReceiveText;
  end else
  begin
    inherited;
  end;
end;
//----------------------------------------}
unit WMCopyDataUnit;

interface

uses
  Windows,
  Messages,
  SysUtils,
//  MECSUtils,

end_uses;

type
  TWMCopyDataConnection = class
  public
    procedure SendText(Handle: THandle; KeyNumber: DWORD; Text: String);
    function ReceiveText(WMCopyDataMessage: TWMCopyData; KeyNumber: DWORD;
     out ReceiveText: String): Boolean;

  end;


implementation

procedure TWMCopyDataConnection.SendText(Handle: THandle; KeyNumber: DWORD;
 Text: String);
var
  CDS: TCopyDataStruct;
begin
  CDS.dwData := KeyNumber;
//  CDS.cbData := (MecsCharToElementLen(Text, MecsLength(Text)) + 1) * StringElementSize(Text);
//  CDS.cbData := (Length(Text) + 1) * SizeOf(Char);
  CDS.cbData := ByteLength(Text) + ByteLength(#0);
  {↑文字列+#0のサイズのバイトを確保する}

  CDS.lpData := PChar(Text);
  SendMessage(Handle, WM_COPYDATA, WPARAM(Handle), LPARAM(Addr(CDS)));
end;

function TWMCopyDataConnection.ReceiveText(WMCopyDataMessage: TWMCopyData;
 KeyNumber: DWORD; out ReceiveText: String): Boolean;
var
  buf: PChar;
begin
  ReceiveText := '';
  Result := False;
  if WMCopyDataMessage.CopyDataStruct.dwData = KeyNumber then
  begin
    Result := True;
    ReceiveText := PChar(WMCopyDataMessage.CopyDataStruct.lpData);
  end;
end;


end.