图表删除在图例上醒目的文本

Question

在chartjs中，一旦我点击任何图例，它就会打击文本并隐藏该特定数据的详细信息。与其删除该文本，我需要将其设置为灰色或其他一些不错的选择。

Answer 1

使用自定义 HTML 图例，您可以根据需要自定义其行为。

下面是一个示例：

var ctx = document.getElementById("myChart").getContext('2d');
var chartData = [60, 90, 120, 150];
var chartLabels = ['apples','bananas','oranges','pears'];
var chart = new Chart(ctx, {
  type: 'pie',
  data: {
    labels: chartLabels,
    datasets: [{
      backgroundColor: [
        "#f43004",
        "#decf3f",
        "#FFA500",
        "#9b59b6",
      ],
      data: chartData
    }]
  },
  options: {
    legend: {
      display: false
    },
    legendCallback: function(chart) {
      var text = [];
      text.push('<ul class="0-legend">');
      var ds = chart.data.datasets[0];
      var sum = ds.data.reduce(function add(a, b) { return a + b; }, 0);
      for (var i=0; i<ds.data.length; i++) {
        text.push('<li>');
        var perc = Math.round(100*ds.data[i]/sum,0);
        text.push('<span style="background-color:' + ds.backgroundColor[i] + '">' + '</span>' + chart.data.labels[i] + ' ('+ds.data[i]+') ('+perc+'%)');
        text.push('</li>');
      }
      text.push('</ul>');
      return text.join("");
    }
  }
});
var myLegendContainer = document.getElementById("legend");
// generate HTML legend
myLegendContainer.innerHTML = chart.generateLegend();
// bind onClick event to all LI-tags of the legend
var legendItems = myLegendContainer.getElementsByTagName('li');
for (var i = 0; i < legendItems.length; i += 1) {
  legendItems[i].addEventListener("click", legendClickCallback, false);
}
function legendClickCallback(event) {
  event = event || window.event;
  var target = event.target || event.srcElement;
  while (target.nodeName !== 'LI') {
    target = target.parentElement;
  }
  var parent = target.parentElement;
  var chartId = parseInt(parent.classList[0].split("-")[0], 10);
  var chart = Chart.instances[chartId];
  var index = Array.prototype.slice.call(parent.children).indexOf(target);
  var meta = chart.getDatasetMeta(0);
  console.log(index);
	var item = meta.data[index];
  if (item.hidden === null || item.hidden === false) {
    item.hidden = true;
    target.classList.add('hidden');
  } else {
    target.classList.remove('hidden');
    item.hidden = null;
  }
  chart.update();
}

body {
    font-family: 'Arial';
}
.container { 
  margin: 15px auto;
}
#chart {
  float: left;
  width: 70%;
}
#legend {
  float: right;
}
[class$="-legend"] {
  list-style: none;
  cursor: pointer;
  padding-left: 0;
}
[class$="-legend"] li {
  display: block;
  padding: 0 5px;
}
[class$="-legend"] li.hidden {
  color: #aaaaaa;
}
[class$="-legend"] li span {
  border-radius: 5px;
  display: inline-block;
  height: 10px;
  margin-right: 10px;
  width: 10px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.js"></script>
<div class="container">
  <div>
      <div id="chart"><canvas id="myChart"></canvas></div>
      <div id="legend"></div>
  </div>
</div>