如何以像素为单位获得条形图宽度

Question

我正在使用chartjs最新版本（2.6.0）。我只是有一个简单的问题，我想得到每个条宽，但我找不到任何答案。有人可以帮帮我吗非常感谢。这是简单的条形图。

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var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
    datasets: [{
      label: '# of Votes',
      data: [12, 19, 3, 5, 2, 3]
    }]
  },
  options: {
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }]
    }
  }
});

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<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas class="canvasChart" id="myChart"></canvas>

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Answer 1

您可以使用.getDatasetMeta()方法在ChartJS中获取每个条的 宽度（基本相同）。

var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
   type: 'bar',
   data: {
      labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
      datasets: [{
         label: '# of Votes',
         data: [12, 19, 3, 5, 2, 3]
      }]
   },
   options: {
      scales: {
         yAxes: [{
            ticks: {
               beginAtZero: true
            }
         }]
      }
   }
});

function getWidth() {
   var barWidth = myChart.getDatasetMeta(0).data[0]._view.width;
   alert(barWidth);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>

<button onclick="getWidth()">Get Bar Width</button>
<canvas class="canvasChart" id="myChart"></canvas>