每个amchart切片的自定义渐变颜色

Question

如何在this饼图中切片的颜色变为所需的渐变颜色而不会失去那种明亮的渐变效果。我使用amcharts（一个JavaScript库）来创建图表。

在code中，每个切片颜色都会自动生成。

<!-- Styles -->
<style>
#chartdiv {
  width: 100%;
  height: 500px;
}

</style>

<!-- Resources -->
<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>

<!-- Chart code -->
<script>
// Themes begin
am4core.useTheme(am4themes_animated);
// Themes end

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

// Add data
chart.data = [{
  "country": "Lithuania",
  "litres": 501.9
}, {
  "country": "Czech Republic",
  "litres": 301.9
}, {
  "country": "Ireland",
  "litres": 201.1
}, {
  "country": "Germany",
  "litres": 165.8
}, {
  "country": "Australia",
  "litres": 139.9
}, {
  "country": "Austria",
  "litres": 128.3
}, {
  "country": "UK",
  "litres": 99
}, {
  "country": "Belgium",
  "litres": 60
}, {
  "country": "The Netherlands",
  "litres": 50
}];

// Add and configure Series
var pieSeries = chart.series.push(new am4charts.PieSeries());
pieSeries.dataFields.value = "litres";
pieSeries.dataFields.category = "country";
pieSeries.innerRadius = am4core.percent(50);
pieSeries.ticks.template.disabled = true;
pieSeries.labels.template.disabled = true;

let rgm = new am4core.RadialGradientModifier();
rgm.brightnesses.push(-0.8, -0.8, -0.5, 0, - 0.5);
pieSeries.slices.template.fillModifier = rgm;
pieSeries.slices.template.strokeModifier = rgm;
pieSeries.slices.template.strokeOpacity = 0.4;
pieSeries.slices.template.strokeWidth = 0;

chart.legend = new am4charts.Legend();
chart.legend.position = "right";
</script>

<!-- HTML -->
<div id="chartdiv"></div>

Answer 1

amcharts使用预定义的颜色集来设置图表的样式。您可以通过不同方式自定义该颜色集：

• 为你的应用程序创建一个全局主题（docs）
• 为一个图表/系列创建自定义颜色集（code pen）

pieSeries.colors.list = [
    am4core.color("#845EC2"),
    am4core.color("#D65DB1"),
    am4core.color("#FF6F91"),
    am4core.color("#FF9671"),
    am4core.color("#FFC75F"),
    am4core.color("#F9F871")
];

• 独立设置每个切片的自定义颜色（code pen）

pieSeries.slices.template.propertyFields.fill = "color";
pieSeries.slices.template.propertyFields.stroke = "color";

此外，您可以添加渐变来设置图表样式。

Here你在amcharts中找到了更多关于颜色和渐变的文档。