Chartjs - 如何在 x 轴标签上获取最后 7 天?

问题描述

我试图在我的折线图的 x 轴上获取最后 7 天(使用 chartjs).最好的方法是什么?

I am trying to get the last seven days on the x-axis of my line-chart (using chartjs). What is the best way to do this?

谢谢

推荐答案

您可以使用以下代码实例化过去 7 天的图表:

You can instantiate a chart for the last seven days with the following code:

let start = new Date(),
  end = new Date();

start.setDate(start.getDate() - 7); // set to 'now' minus 7 days.
start.setHours(0, 0, 0, 0); // set to midnight.

new Chart(document.getElementById("chart"), {
  type: "line",
  options: {
    scales: {
      xAxes: [{
        type: "time",
        time: {
          min: start,
          max: end,
          unit: "day"
        }
      }]
    }
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.bundle.min.js"></script>
<canvas id="chart"></canvas>

日期算术之所以有效是因为 日期对象在设置月份的值无效时自动更正.

The date arithmetic works because of the Date object auto correcting itself when the value is invalid for the set month.

您需要将值提供为 x(或 t)&y 属性，指定在文档中.

You'll need to provide your values as x (or t) & y properties, as specified in the documentation.

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