在MFC中可以通过下面两句取得控件的句柄:
CRichEditCtrl* pRichEdit = (CRichEditCtrl*)(CWnd::FromHandle(hwnd));//hwnd是上面两句获得的句柄,转化为对应控件的指针
CString szRichMsg;
szRichMsg.Format("%s",msg.c_str());
CString szUname;
std::string uname=stanza->from().username();
szUname.Format("%s",uname.c_str());
pRichEdit->ReplaceSel((szUname+"\t"+m_Time)+"\n"+szRichMsg+"\n");//使用控件指针