使用 Chartjs 按值排序和隐藏图例项 Angular

Question

如果提供的值为 0，我想隐藏或不显示图例，并按升序排列项目

export class DoughnutChartComponent {

  doughnutChartLabels: Label[] = ['CR1', 'CR2', 'CR3', 'CR4', 'CR5', 'BOX', 'APP', 'Center 8', 'Center 9'];
  doughnutChartData: number [] = [55, 25, 20, 0, 54, 33, 0, 70, 88];
  doughnutChartOptions: ChartOptions = { legend: {
      display: true,
      position: 'right',
      fullWidth:false,
      reverse: false,
      labels: {
        usePointStyle: true,
        boxWidth: 10,
        padding: 7,
        fontSize: 18,
        fontColor: '#003457',
        fontStyle: 'bold',
      },
      },
     cutoutPercentage: 70,
    };
  doughnutChartType: ChartType = 'doughnut';
  doughnutChartColor: Colors[] = [{
    backgroundColor: [
      '#2E9FE0',
      '#9CCA32',
      '#255FCC',
      '#B746A6',
      '#FF9232',
      '#03B075',
      '#E5D844',
      '#45D2E4',
      '#E0489A'
    ]
  }] ;
}

可以吗。因为我没有得到任何解决方案。感谢帮助

Answer 1

基本可以通过Array.filter(), followed by Array.sort()实现。

由于这需要在 doughnutChartLabels 和 doughnutChartData 上同时完成，您应该首先将标签和相应的值包装到对象中，然后在最后解开这些对象，两者都使用 Array.map() .

为此，您可以将以下 constructor 添加到 DoughnutChartComponent。

constructor() {
  const tmp = doughnutChartData
    .map((v, i) => ({ l: doughnutChartLabels[i], v: v }))
    .filter(o => o.v > 0)
    .sort((o1, o2) => o1.v - o2.v);
  doughnutChartLabels = tmp.map(o => o.l);
  doughnutChartData = tmp.map(o => o.v);
}

Answer 2

您可以像这样使用 chart.js 提供的图例标签的过滤功能：

var options = {
  type: 'doughnut',
  data: {
    labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
    datasets: [{
      label: '# of Votes',
      data: [12, 19, 3, 5, 2, 0],
      borderWidth: 1,
      backgroundColor: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"]
    }]
  },
  options: {
    legend: {
      labels: {
        filter: (legendItem, chartData) => {
          const index = chartData.labels.indexOf(legendItem.text)
          return chartData.datasets[0].data[legendItem.index] !== 0
        }
      }
    }
  }
}

var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);

<body>
  <canvas id="chartJSContainer" width="600" height="400"></canvas>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js" integrity="sha512-hZf9Qhp3rlDJBvAKvmiG+goaaKRZA6LKUO35oK6EsM0/kjPK32Yw7URqrq3Q+Nvbbt8Usss+IekL7CRn83dYmw==" crossorigin="anonymous"></script>
</body>

使用 Chartjs 按值排序和隐藏图例项 Angular

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