Cesium点击地图获取经纬度

onClick(viewer) {
     //获取被点击的canvas
    var canvas= new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
    canvas.setInputAction(function (event) {
        var earthPosition  = viewer.camera.pickEllipsoid(event.position,viewer.scene.globe.ellipsoid);
        var cartographic = Cesium.Cartographic.fromCartesian(earthPosition, viewer.scene.globe.ellipsoid, new Cesium.Cartographic());
        var lat=Cesium.Math.toDegrees(cartographic.latitude);
        var lng=Cesium.Math.toDegrees(cartographic.longitude);
        var height=cartographic.height;
        console.log(`经度：${lng}，纬度：${lat}，高度：${height}`);
    }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
},