javascript - 将鼠标悬停在图表上时如何显示百分比？

Question

情况：

我希望在您将鼠标悬停在图表上时获得的数字工具提示旁边添加一个百分比。我怎样才能做到这一点？例如，我想在 .%旁边添加一个标志83.33。

---

错误：

ERROR TypeError: Cannot read property '0' of undefined
at i.label (eval at <anonymous> (http://localhost:3000/js/app/bundle.js:1564:1), <anonymous>:37:63)

---

代码：

// Pie
public pieChartLabels:string[] = [];
public pieChartData:number[] = [];
public pieChartType:string = 'pie';
public pieChartOptions:any = {};

ngOnInit() {
    var result1 = parseFloat(((this.poll.counter1/(this.poll.counter2+this.poll.counter1))*100).toFixed(2));
    var result2 = parseFloat(((this.poll.counter2/(this.poll.counter2+this.poll.counter1))*100).toFixed(2));
    this.pieChartData = [result1, result2];
    this.pieChartLabels = [this.poll.choice1, this.poll.choice2];
    this.pieChartType = 'pie';
    this.pieChartOptions  = {
                            tooltips: {
                                callbacks: {
                                    label: function (tooltipItems, data) {
                                            return data.datasets[tooltipItems.datasetIndex].label + ': ' +
                                                tooltipItems.pieChartLabels[tooltipItems.datasetIndex].replace(/(\d)(?=(\d{3})+\.)/g, '$1,');
                                           }
                                    }
                                }

                            }

    // events
public chartClicked(e:any):void {

}

public chartHovered(e:any):void {

}

Answer 1

您可以使用 chart.js 中的工具提示回调来更改工具提示后缀。这是一个关于如何添加 % 的示例。我通过进行一些搜索并找到其他示例来解决这个问题。

https://jsfiddle.net/nt50dzb7/

  options: {
    tooltips: {
      enabled: true,
      mode: 'single',
      callbacks: {
        label: function(tooltipItem, data) {
          var allData = data.datasets[tooltipItem.datasetIndex].data;
          var tooltipLabel = data.labels[tooltipItem.index];
          var tooltipData = allData[tooltipItem.index];
          return tooltipLabel + ": " + tooltipData + "%";
        }
      }
    }
  }
}