let contextmenu = new KMap.Contextmenu()
contextmenu.addItem("放大一级", (e) => {
       let zoom = map.getZoom();
       map.setZoom(zoom + 1, 500);
       map.close(contextmenu);
});
map.on("rightclick", function (e) {
       map.open(contextmenu, e.position);
});

map.off("rightclick"); //将地图的rightclick右键点击事件移除