如何知道在 amcharts 中的堆叠条形图上单击了哪个类别？

Question

我有一个堆叠条形图并在其上分配了一个点击侦听器以了解点击了哪个项目。

series.columns.template.events.on("hit", function(ev) {
    console.log(ev.target);
}, this);

但是在相应的 target.dataItem json 中我找不到任何点击了类别的字段。只有年份和数值可用。如何获取实际图例类别？
Codepen implementation

Answer 1

您可以通过target.dataItem.component访问系列信息。这将包含用于填充图例的系列信息，例如名称。

series.columns.template.events.on("hit", function(ev) {
    console.log(ev.target.dataItem.component.name);
}, this);

下面的演示：

// Themes begin
am4core.useTheme(am4themes_animated);
// Themes end

// Create chart instance
var chart = am4core.create("chartdiv", am4charts.XYChart);

// Add data
chart.data = [{
  "year": "2016",
  "europe": 2.5,
  "namerica": 2.5,
  "asia": 2.1,
  "lamerica": 0.3,
  "meast": 0.2,
  "africa": 0.1
}, {
  "year": "2017",
  "europe": 2.6,
  "namerica": 2.7,
  "asia": 2.2,
  "lamerica": 0.3,
  "meast": 0.3,
  "africa": 0.1
}, {
  "year": "2018",
  "europe": 2.8,
  "namerica": 2.9,
  "asia": 2.4,
  "lamerica": 0.3,
  "meast": 0.3,
  "africa": 0.1
}];

chart.legend = new am4charts.Legend();
chart.legend.position = "right";

// Create axes
var categoryAxis = chart.yAxes.push(new am4charts.CategoryAxis());
categoryAxis.dataFields.category = "year";
categoryAxis.renderer.grid.template.opacity = 0;

var valueAxis = chart.xAxes.push(new am4charts.ValueAxis());
valueAxis.min = 0;
valueAxis.renderer.grid.template.opacity = 0;
valueAxis.renderer.ticks.template.strokeOpacity = 0.5;
valueAxis.renderer.ticks.template.stroke = am4core.color("#495C43");
valueAxis.renderer.ticks.template.length = 10;
valueAxis.renderer.line.strokeOpacity = 0.5;
valueAxis.renderer.baseGrid.disabled = true;
valueAxis.renderer.minGridDistance = 40;

// Create series
function createSeries(field, name) {
  var series = chart.series.push(new am4charts.ColumnSeries());
  series.dataFields.valueX = field;
  series.dataFields.categoryY = "year";
  series.stacked = true;
  series.name = name;
  
  var labelBullet = series.bullets.push(new am4charts.LabelBullet());
  labelBullet.locationX = 0.5;
  labelBullet.label.text = "{valueX}";
  labelBullet.label.fill = am4core.color("#fff");
  
   series.columns.template.events.on("hit", function(ev) {
        console.log(ev.target.dataItem.component.name);
    }, this);
}

createSeries("europe", "Europe");
createSeries("namerica", "North America");
createSeries("asia", "Asia");
createSeries("lamerica", "Latin America");
createSeries("meast", "Middle East");
createSeries("africa", "Africa");

#chartdiv {
  width: 100%;
  height: 500px;
}

<script src="https://www.amcharts.com/lib/4/core.js"></script>
<script src="https://www.amcharts.com/lib/4/charts.js"></script>
<script src="https://www.amcharts.com/lib/4/themes/animated.js"></script>
<div id="chartdiv"></div>

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