添加事件的时候出错

NeXT

int main(int, char**)
{
         osgViewer::Viewer viewer;
         osg::ref_ptr<osg::Group> root = new osg::Group();
         root->addChild(osgDB::readNodeFile("cessna.osg"));
         osg::ref_ptr<osg::Node> cow = osgDB::readNodeFile("cow.osg");

        osg::ref_ptr<osgFX::Scribe> sc = new osgFX::Scribe();
        sc->addChild(cow.get());

        root->addChild(cow.get());
        root->addChild(sc.get());
        viewer.setSceneData(root.get());
       
        viewer.addEventHandler(new CPickHandler(&viewer));
        viewer.realize();
    viewer.run();
        return 0;
}


        viewer.addEventHandler(new CPickHandler(&viewer));这里一直有报错：
错误        1        error C2061: 语法错误: 标识符“CPickHandler”        g:\osgstudy\day2\eventhandler\eventhandler\addevent.cpp        42        1        EventHandler


有人知道是为什么吗