javascript - chart.js 加载全新数据

Question

The API for chart.js允许编辑加载到其中的数据集的点，例如:

.update( )

Calling update() on your Chart instance will re-render the chart with any updated values, allowing you to edit the value of multiple existing points, then render those in one animated render loop.

.addData( valuesArray, label )

Calling addData(valuesArray, label) on your Chart instance passing an array of values for each dataset, along with a label for those points.

.removeData( )

Calling removeData() on your Chart instance will remove the first value for all datasets on the chart.

所有这些都很棒，但我不知道如何加载一个全新的数据集，同时清除旧的。文档似乎没有涵盖这一点。

Answer 1

我遇到了很大的问题

首先我尝试了 .clear()然后我试了.destroy()我尝试将我的图表引用设置为 null

最终为我解决了问题:删除 <canvas>元素，然后重新附加一个新的 <canvas>到父容器

---

有一百万种方法可以做到这一点:

var resetCanvas = function () {
  $('#results-graph').remove(); // this is my <canvas> element
  $('#graph-container').append('<canvas id="results-graph"><canvas>');
  canvas = document.querySelector('#results-graph'); // why use jQuery?
  ctx = canvas.getContext('2d');
  ctx.canvas.width = $('#graph').width(); // resize to parent width
  ctx.canvas.height = $('#graph').height(); // resize to parent height

  var x = canvas.width/2;
  var y = canvas.height/2;
  ctx.font = '10pt Verdana';
  ctx.textAlign = 'center';
  ctx.fillText('This text is centered on the canvas', x, y);
};