用PostMessage传参数

用PostMessage传参数
需要注意的事项：
由于PostMessage是异步执行的，所以参数要用new CString，然后在接收方释放


发送端：
CString* msg = new CString(desc.c_str());
PostMessage(CCounterHelper::GetInstance()->GetLoginDlgHandle(),WM_LOGIN_COUNTER_ERR,0,(LPARAM)msg);
...


接受端：
case WM_LOGIN_COUNTER_ERR:
{
CString* rmsg = (CString*)lParam;
SetStatusTxt(rmsg->GetBuffer(rmsg->GetLength()));
rmsg->ReleaseBuffer();
delete rmsg;
...