FindWindow 两程序通信 TCopyDataStruct

{FindWindow 的两个参数: 
第一个: 是类名, 计算器的类名是: SciCalc 
第二个: 是标题名 
两个参数有其一即可,格式: }

h := FindWindow('SciCalc', nil);
h := FindWindow(nil, '计算器'); 

procedure SendMsg(AppName,Msg:string);
var
  ds: TCopyDataStruct;
  handle:THandle;
begin
  ds.cbData:=Length(Msg)+1;
  GetMem(ds.lpData,ds.cbData);
  try
    StrCopy(ds.lpData,PChar(Msg));
    handle:=FindWindow(nil,Pchar(AppName));
    handle:=FindWindow('TReceiveFrm',nil));
    SendMessage(handle, WM_COPYDATA, 0, Integer(@ds));
  finally
    FreeMem(ds.lpData,ds.cbData);
  end;
end;

{调用:}
  SendMsg('Receie窗口','Hello World');

  public
     procedure WMCopyData(var Msg: TWMCOPYDATA); message WM_COPYDATA;

procedure TReceiveFrm.WMCopyData(var Msg: TWMCOPYDATA);
begin
  showmessage(StrPas(Msg.CopyDataStruct^.lpData));
end;