ChartJs 如何从多个数据集获取单击哪个数据集栏

Question

我想为每个栏添加一个唯一的网址，并在单击栏之一时打开该网址。但就我而言，我有两个数据集。我正在使用 onClick 事件，它返回两个数据集的活动记录。

我正在使用以下代码......它将返回两个数据集对象......它应该只返回一个数据集。

<script>
        var barChartData = {
            labels: ["Jan","Feb","March"],
            datasets: [{
                label : "Quoted",
                backgroundColor : "#FF7228",
                data : [50,20,70],
            },
            {
                label : "Accepted",
                backgroundColor : "#FFCC8C",
                data :  [30,10,20],
            }, 
            ]

        };

        window.onload = function() {
            var ctx = document.getElementById("canvas").getContext("2d");
            window.myBar = new Chart(ctx, {
                type: 'bar',
                data: barChartData,
                options: {
                    events:['click'],
                    onClick:function(c,i){
                            console.log(this.active);
                            }
                        },
                    responsive: true,
                    legend: {
                        position: 'top',
                    },
                }
            });
        };
 </script>

Answer 1

您可以使用getElementAtEvent()方法只返回一个数据集。然后您可以应用进一步的逻辑来检测点击了哪个栏。

？？？

var barChartData = {
   labels: ["Jan", "Feb", "March"],
   datasets: [{
      label: "Quoted",
      backgroundColor: "#FF7228",
      data: [50, 20, 70],
   }, {
      label: "Accepted",
      backgroundColor: "#FFCC8C",
      data: [30, 10, 20],
   }]
};

var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx, {
   type: 'bar',
   data: barChartData,
   options: {
      onClick: function(e) {
         var bar = this.getElementAtEvent(e)[0];
         var index = bar._index;
         var datasetIndex = bar._datasetIndex;

         // check which bar is clicked
         if (index == 0 && datasetIndex == 0) alert('First BAR Clicked!');
         else if (index == 0 && datasetIndex == 1) alert('Second BAR Clicked!');
         else if (index == 1 && datasetIndex == 0) alert('Third BAR Clicked!');
         else if (index == 1 && datasetIndex == 1) alert('Fourth BAR Clicked!');
         else if (index == 2 && datasetIndex == 0) alert('Fifth BAR Clicked!');
         else if (index == 2 && datasetIndex == 1) alert('Sixth BAR Clicked!');
      }
   },
   responsive: true,
   legend: {
      position: 'top',
   },
});

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