使用 d3.js 向饼图添加工具提示-前端问题

adding tooltips to pie chart using d3.js(使用 d3.js 向饼图添加工具提示)

本文介绍了使用 d3.js 向饼图添加工具提示的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在开始学习使用 d3.js 可视化数据的旅程，到目前为止，我发现 Scott Murray 的交互式数据可视化"非常有用.我正在阅读本书第 11 章中的一些示例代码，并且想知道如何将工具提示添加到饼图中(本书已经使用条形图描述了此过程).无论如何，过去几个小时一直在修改代码，想看看是否有人可以帮我解决这个问题:

I am embarking on a journey to learn to visualize data using d3.js, and so far I am finding the "Interactive Data Visualization" by Scott Murray very helpful. I was following through some of the example codes in book chapter 11, and was wondering how I would add the tooltip to the pie chart (the book already describes this procedure using the bar chart). Anyways, just been tinkering around with the codes for past couple of hours and would like to see if anyone can lend me a hand on this:

<!DOCTYPE html>
<html lang="en">
<head>
   <meta charset="utf-8">
   <title>D3: Pie layout</title>
   <script type="text/javascript" src="d3/d3.v3.js"></script>
   <style type="text/css">

            text {
               font-family: sans-serif;
               font-size: 12px;
               fill: white;
            }

            #tooltip {
               position: absolute;
               width: 200px;
               height: auto;
               padding: 10px;
               background-color: white;
               -webkit-border-radius: 10px;
               -moz-border-radius: 10px;
               border-radius: 10px;
               -webkit-box-shadow: 4px 4px 10px rgba(0, 0, 0, 0.4);
               -mox-box-shadow: 4px 4px 4px 10px rgba(0, 0, 0, 0.4);
               box-shadow: 4px 4px 10px rbga(0, 0, 0, 0.4)
               pointer-events: none;
            }

            #tooltip.hidden {
               display: none;
            }

           #tooltip p {
               margin: 0;
               font-family: sans-serif;
               font-size: 16px;
                        line-height: 20px;
           }
   </style>
</head>

<body>
    <div id="tooltip" class="hidden">
            <p><strong>Important Label Heading</strong></p>
            <p><span id="value">100</span>%</p>
    </div>
    <script type="text/javascript">

        //Width and height
        var w = 300;
        var h = 300;

        var dataset = [ 5, 10, 20, 45, 6, 25 ];

        var outerRadius = w / 2;
        var innerRadius = 0;
        var arc = d3.svg.arc()
                        .innerRadius(innerRadius)
                        .outerRadius(outerRadius);

        var pie = d3.layout.pie();

        // Easy colors accessible via a 10-step ordinal scale
        var color = d3.scale.category10();

        // Create SVG element
        var svg = d3.select("body")
                    .append("svg")
                    .attr("width", w)
                    .attr("height", h);

        // Set up groups
        var arcs = svg.selectAll("g.arc")
                      .data(pie(dataset))
                      .enter()
                      .append("g")
                      .attr("class", "arc")
                      .attr("transform", "translate(" + outerRadius + "," + outerRadius + ")")
                      .on("mouseover", function(d){
                        d3.select("#tooltip")
                          .select("#value")
                          .text(d);

                        d3.select("tooltip").classed("hidden",false);
                      })
                      .on("mouseout", function() {
                        // Hide the tooltip
                        d3.select("#tooltip").classed("hidden", true);
                      });

        // Draw arc paths
        arcs.append("path")
            .attr("fill", function(d, i) {
                 return color(i);
            })
            .attr("d", arc);

        // Labels
        arcs.append("text")
            .attr("transform", function(d) {
                 return "translate(" + arc.centroid(d) + ")";
            })
            .attr("text-anchor", "middle")
            .text(function(d) {
                 return d.value;
            });
    </script>
</body>
</html>

我知道这有点难以理解，但我想更具体地了解如何设置工具提示的 x 和 y 值.提前谢谢你.

I know this is bit to digest, but what I want to know more specifically is how to set the x and y value for the tool-tip. Thank you in advance.