splitArea 间隔echarts 柱状配置项内容和展示

      const dataAxis = ["2014.5", "2014.6", "2014.7", "2014.8", "2014.9", "2014.10", "2014.11", "2014.12", "2015.1", "2015.2", "2015.3", "2015.4", "2015.5", "2015.6", "2015.7", "2015.8", "2015.9", "2015.10", "2015.11", "2015.12", "2016.1", "2016.2", "2016.3", "2016.4", "2016.5", "2016.6", "2016.7", "2016.8", "2016.9", "2016.10", "2016.11", "2016.12", "2017.1", "2017.2", "2017.3", "2017.4"]
const dataBar = [38, 95, 69, 70, 72, 90, 54, 50, 77, 62, 69, 71, 85, 77, 69, 56, 74, 67, 74, 61, 85, 98, 98, 78, 94, 116, 77, 61, 80, 120, 104, 89, 95, 109, 160, 0]
option = {
    tooltip: {
        position: 'left',
        formatter: 'Date:{b}<br />Article:{c}',
    },
    grid: {
        left: 0,
        right: 0,
        top: 0,
        bottom: this.isxAxis ? 40 : 20,
    },
    xAxis: {
        data: dataAxis,
        axisLabel: {
            show: false,
            textStyle: {
                color: '#414b56',
            },
        },
        axisTick: {
            show: false,
        },
        axisLine: {
            show: true,
            lineStyle: {
                color: 'rgba(121, 128, 135, 0.8)',
                type: 'dashed',
            },
        },
        splitLine: {
            show: false,
        },
        splitArea: {
            show: true,
            interval: (function() {
                var lastYear;
                return (index, value) => {
                    if (value) {
                        const year = value.split('.', 1)[0];
                        var ignore = year === lastYear;
                        lastYear = year;
                        
                        return !ignore;
                    } else {
                        return false
                    }
                }
            })()
        },

        z: 10,
    },
    yAxis: {
        splitLine: {
            show: false,
        },
        axisLine: {
            show: false,
        },
        axisTick: {
            show: false,
        },
        axisLabel: {
            show: false,
        },
    },
    series: [{
        type: 'bar',
        itemStyle: {
            normal: {
                color: '#99c868',
                barBorderRadius: [3, 3, 0, 0],
            },
            emphasis: {
                color: '#dce5d1',
                barBorderRadius: [3, 3, 0, 0],
            },
        },
        data: dataBar,
    }, ],
};