d3.js可以画矢量图不难，难在如何拖拽，其实jquery甚至easyui都提供了draggable的拖放方法，只需要在拖动一个div的drop事件执行的时候重新绘制line即可，实现起来就太简单了，用来做代码生成器或报表工具或工作流简直爽哉！！！ 我也可以融合到我的easydragger开源软件里，形成新的更加强大的产品，鸟无翅不可飞，车无轮不可跑，代码设计器无矢量图就是垃圾，无法导向人脑的认知系统，大家祝愿我完成吧，然后让各位早些下载下来用用。接下来我拖拽将进行。祈祷吧。世界终会安宁。

<code class="language-html">  
    
        <meta charset="utf-8">  
        <title>Arrow</title>  
   
  
<script src="d3.v3.min.js" charset="utf-8"></script>  
<script> 
  
var width  = 400;
var height = 400;
     
var svg = d3.select("body").append("svg")
        .attr("width", width)
        .attr("height", height);
         
var defs = svg.append("defs");
  
var arrowMarker = defs.append("marker")
                        .attr("id","arrow")
                        .attr("markerUnits","strokeWidth")
                        .attr("markerWidth","12")
                        .attr("markerHeight","12")
                        .attr("viewBox","0 0 12 12") 
                        .attr("refX","6")
                        .attr("refY","6")
                        .attr("orient","auto");
  
var arrow_path = "M2,2 L10,6 L2,10 L6,6 L2,2";
                         
arrowMarker.append("path")
            .attr("d",arrow_path)
            .attr("fill","#000");
  
var line = svg.append("line")
             .attr("x1",0)
             .attr("y1",0)
             .attr("x2",200)
             .attr("y2",50)
             .attr("stroke","red")
             .attr("stroke-width",2)
             .attr("marker-end","url(#arrow)");
  
var curve_path = "M20,70 T80,100 T160,80 T200,90";
  
var curve = svg.append("path")
             .attr("d",curve_path)
             .attr("fill","white")
             .attr("stroke","red")
             .attr("stroke-width",2)
             .attr("marker-start","url(#arrow)")
             .attr("marker-mid","url(#arrow)")
             .attr("marker-end","url(#arrow)");
              
  
</script>  
  
  </code>