Highcharts:突出显示选定/活动按钮

Highcharts.chart('container', {
    chart: {
        type: 'line'
    },
    title: {
        text: '突出显示活动按钮示例'
    },
    xAxis: {
        categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
    },
    yAxis: {
        title: {
            text: 'Temperature (°C)'
        }
    },
    series: [{
        name: 'Tokyo',
        data: [7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6]
    }, {
        name: 'London',
        data: [3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 16.6, 14.2, 10.3, 6.6, 4.8]
    }],
    exporting: {
        buttons: {
            contextButton: {
                onclick: function () {
                    // 高亮当前按钮
                    this.exporting.buttons.contextButton.element.classList.add('highcharts-active');
                },
                onmouseout: function () {
                    // 移除高亮
                    this.exporting.buttons.contextButton.element.classList.remove('highcharts-active');
                }
            }
        }
    }
});