首先我们要明白如何在svg中进行箭头的绘制:
先写一对<defs>,里面再写一对<marker>,其中marker的属性意义为:
viewBox | 坐标系的区域 |
refX, refY | 在 viewBox 内的基准点,绘制时此点在直线端点上(要注意大小写) |
markerUnits | 标识大小的基准,有两个值:strokeWidth(线的宽度)和userSpaceOnUse(图形最前端的大小) |
markerWidth, markerHeight | 标识的大小 |
orient | 绘制方向,可设定为:auto(自动确认方向)和 角度值 |
id | 标识的id号 |
然后,我们利用d3.js来进行箭头的绘制就清楚多了:
//添加defs标签 var defs = svg.append("defs"); //添加marker标签及其属性 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")
//绘制直线箭头 var arrow_path = "M2,2 L10,6 L2,10 L6,6 L2,2"; arrowMarker.append("path") .attr("d",arrow_path) .attr("fill","#000") //绘制直线 var line = svg.append("line") .attr("x1",50) .attr("y1",50) .attr("x2",200) .attr("y2",400) .attr("stroke","red") .attr("stroke-width",2) .attr("marker-start","url(#arrow)") .attr("marker-end","url(#arrow)")
//绘制曲线箭头 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)");
在不同的位置绘制的属性如下:
- marker-start :路径起点处
- marker-mid:路径中间端点处(必须是 path 中间出现的点)
- marker-end :路径终点处
绘制结果如下:
时间: 2024-11-09 00:59:54