进程通讯之WM_COPYDATA

发送程序（SendData.exe）：

 

unit SendUnit;

interface

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

type
  TFrmSend = class(TForm)
    BtnSend: TButton;
    procedure BtnSendClick(Sender: TObject);
  private
    { Private declarations }

  public
    { Public declarations }
  end;

var
  FrmSend: TFrmSend;

implementation

{$R *.dfm}

{ TFrmRecv }

procedure TFrmSend.BtnSendClick(Sender: TObject);
var
  _vMsg : string;
  i, _vLen : Integer;
  _vBuf : array of Char;
  _vCopyData : TCopyDataStruct;
  _vHandle: THandle;
begin
  _vMsg := '我是来自另外一个进程的消息！';

  _vLen := Length(_vMsg);
  SetLength(_vBuf, _vLen);
  for i := 0 to _vLen - 1 do
    _vBuf[i] := _vMsg[i + 1];
  _vCopyData.dwData := 100;
  _vCopyData.cbData := _vLen;
  _vCopyData.lpData := _vBuf;

  _vHandle := FindWindow('TFrmRecv', '接收程序');
  if _vHandle <> 0 then
    SendMessage(_vHandle, WM_COPYDATA, 0, longint(@_vCopyData));
end;

end.

 

接收程序(RecvData.exe):

 

unit RecvUnit;

interface

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

type
  TFrmRecv = class(TForm)
  private
    { Private declarations }
    procedure RecvMessage(var aMsg: TWMCOPYDATA); message WM_COPYDATA;
  public
    { Public declarations }
  end;

var
  FrmRecv: TFrmRecv;

implementation

{$R *.dfm}

{ TFrmSend }

procedure TFrmRecv.RecvMessage(var aMsg: TWMCOPYDATA);
var
  _vBufLen : Integer;
  _vBuf : array of Char;
  i : Integer;
  _vStr : string;
begin
  if aMsg.CopyDataStruct^.dwData = 100 then
  begin
    _vBufLen := aMsg.CopyDataStruct^.cbData;
    System.SetLength(_vBuf, _vBufLen);
    Move(aMsg.CopyDataStruct^.lpData^, _vBuf[0], _vBufLen);

    _vStr := '';
    for i := 0 to _vBufLen - 1 do
      _vStr := _vStr + _vBuf[i];
    ShowMessage('Len: ' + IntToStr(_vBufLen) + '  ' + _vStr);
  end;
end;

end.