我想知道是否有替代方法可以将 "stroke-dasharray" 应用于路径。我想要做的是在路径中的某个范围内添加一条虚线。问题是这条线不直。我想避免使用不同范围内的相同数据创建两条线。有没有人有想法?

javascript - 使单条线为实线,其中一部分为虚线-LMLPHP

最佳答案

我链接了这个 question ,它提供了 stroke-dasharray 如何工作的一个很好的概述,但这个问题的有趣部分变成了,我怎样才能冲过该行的特定部分?考虑到这一点,假设我们有一条从 0 到 10 的线,我们想把它从 2.5 划到 7:

<!DOCTYPE html>
<meta charset="utf-8">
<style>
  body {
    font: 10px sans-serif;
  }

  .axis path,
  .axis line {
    fill: none;
    stroke: #000;
    shape-rendering: crispEdges;
  }

  .x.axis path {
    display: none;
  }

  .line {
    fill: none;
    stroke: steelblue;
    stroke-width: 1.5px;
  }
</style>

<body>
  <script src="//d3js.org/d3.v4.min.js"></script>
  <script>
    var margin = {
        top: 20,
        right: 20,
        bottom: 30,
        left: 50
      },
      width = 960 - margin.left - margin.right,
      height = 500 - margin.top - margin.bottom;

    var data = d3.range(11).map(function(d, i) {
      return {
        x: i,
        y: Math.random() * 100
      };
    });

    var x = d3.scaleLinear()
      .range([0, width])
      .domain([0, 10]);

    var y = d3.scaleLinear()
      .range([height, 0])
      .domain([0, 100]);

    var xAxis = d3.axisBottom()
      .scale(x);

    var yAxis = d3.axisLeft()
      .scale(y);

    var line = d3.line()
      .x(function(d) {
        return x(d.x);
      })
      .y(function(d) {
        return y(d.y);
      })
      .curve(d3.curveBasis);

    var svg = d3.select("body").append("svg")
      .attr("width", width + margin.left + margin.right)
      .attr("height", height + margin.top + margin.bottom)
      .append("g")
      .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

    svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

    svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)

    var p = svg.append("path")
      .datum(data)
      .attr("class", "line")
      .attr("d", line);

    // draw dashed from 2.7 to 7 in the X domain
    var dashBetweenX = [2.5, 7]
        path = p.node(),
        totalLen = path.getTotalLength();

    // find the corresponding line lengths
    var dashBetweenL = dashBetweenX.map(function(d,i){

      var beginning = 0,
          end = totalLen,
          target = null,
          d = x(d);

      // find the line lengths the correspond to our X values
      // stolen from @duopixel from http://bl.ocks.org/duopixel/3824661
      while (true){
        target = Math.floor((beginning + end) / 2);
        pos = path.getPointAtLength(target);
        if ((target === end || target === beginning) && pos.x !== d) {
            break;
        }
        if (pos.x > d) end = target;
        else if (pos.x < d) beginning = target;
        else break; //position found
      }

      return target;
    })

    // draw the dashes
    var sd =  dashBetweenL[0],
        dp = dashBetweenL[0],
        count = 0;
    while (dp < dashBetweenL[1]){
      dp += 2;
      sd += ", 2";
      count++;
    }
    // per answer below needs odd number of dash array
    if (count % 2 == 0)
      sd += ", 2";
    sd += ", " + (totalLen - dashBetweenL[1]);
    p.attr("stroke-dasharray", sd);
  </script>
</body>

</html>

关于javascript - 使单条线为实线,其中一部分为虚线,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/35000044/

10-15 23:30