cesium怎么监听地图的缩放还有拖动啊

/ 鼠标滚轮事件
		var camera=viewer.camera;
		var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
        handler.setInputAction(function(wheelment) {
        	var height=camera.positionCartographic.height;
    	    if(height<100000){
			   viewer.camera.setView({
			    destination : Cesium.Cartesian3.fromRadians(viewer.camera.positionCartographic.longitude, viewer.camera.positionCartographic.latitude, 100000)
				});
    	 	};
    	 	if(height>10000000){
    	 		viewer.camera.setView({
			    destination : Cesium.Cartesian3.fromRadians(viewer.camera.positionCartographic.longitude, viewer.camera.positionCartographic.latitude, 10000000)
				});
    	 	}
        }, Cesium.ScreenSpaceEventType.WHEEL);

Viewer.scene.postRender.addEventListener(function(){ ... })