2D圖紙怎么調(diào)用Annotation的接口，實現(xiàn)畫批注的效果？

//創(chuàng)建批注
function createAnnotation(viewer){

var config = new Glodon.Bimface.Plugins.Annotation.AnnotationToolbarConfig();
config.viewer = viewer;//2D圖紙
annotationToolbar = new Glodon.Bimface.Plugins.Annotation.AnnotationToolbar(config);
AnnotationToolbarEvent = Glodon.Bimface.Plugins.Annotation.AnnotationToolbarEvent
annotationToolbar.addEventListener(AnnotationToolbarEvent.Saved,function(list){
  list = list;
});
annotation = annotationToolbar.getAnnotationManager();
annotationToolbar.show()

}

//導(dǎo)出截屏

var prop = document.getElementById("prop");
var content = document.getElementById("content");
var close = document.getElementById("close");
document.getElementById("createSnapshot").addEventListener("click",function(){

annotation.createSnapshot(function(image){
  var img = new Image();
  img.src = image;
  prop.style.display = "block";
  content.innerHTML = "";
  content.appendChild(img);
})

});