javascript - 如何使用 chart.js 在图条上方显示值标签

Question

我正在使用 chart.js，我想在条形上方显示标签值，那么该怎么做呢？

var barChartData = {
  labels: ["January", "February", "March", "April", "May", "June", "July"],
  datasets: [{
    fillColor: "rgba(220,220,220,0.5)",
    strokeColor: "rgba(220,220,220,1)",
    data: [65, 59, 90, 81, 56, 55, 40],
  }]
}

Answer 1

我遇到了同样的问题，决定写出来。请从我在 github 上的 fork 版本获取我的 chart.js 版本:Chart.js

您可以传递以下选项:

var barChartData = {
  labels: ["January", "February", "March", "April", "May", "June", "July"],
  datasets: [{
    fillColor: "rgba(220,220,220,0.5)",
    strokeColor: "rgba(220,220,220,1)",
    data: [65, 59, 90, 81, 56, 55, 40],
  }]
};
var opts = {
    scaleShowValues: true, 
    scaleValuePaddingX: 13,
    scaleValuePaddingY: 13
};
var chrt = document.getElementById('chrtDemo').getContext('2d');
new Chart(chrt).Bar(barChartData, opts);

scaleValuePaddingX 和 scaleValuePaddingY 会移动值的位置，以便您对其进行微调。

您还可以传递一个颜色数据集来单独为每个条形着色:

var barChartData = {
  labels: ["January", "February", "March"],
  datasets: [{
    fillColor: ["rgba(220,220,220,0.5)", "rgba(220,220,220,0.5)", "rgba(220,220,220,0.5)"],
    strokeColor: ["rgba(220,220,220,1)", "rgba(220,220,220,1)", "rgba(220,220,220,1)"],
    data: [65, 59, 90],
  }]
};