CClrButton  button_1; //新BUTTON类创建的对象
                           button_1.SubclassDlgItem(IDC_BUTTON1,this);//运行正常                           CClrButton *p_button; //新BUTTON类创建的指针 
                           p_button = (CClrButton*)GetDlgItem( IDC_BUTTON1) ;
         p_button -> SubclassDlgItem(IDC_BUTTON1,this);  //运行出错请教下用为什么出错了?