javascript - 如何显示 x 轴 Highcharts 的第一个和最后一个标签

Question

我在其他答案上尝试了一些解决方案，但无法得到我想要的结果..请帮助我。

我想在 highcharts 中显示第一个 x 轴标签和最后一个 x 轴标签。

我尝试了这个答案( Force Highcharts to show last x-axis label )中的 {endOnTick: true, showLastLabel: true} 但它只显示最后一个数字..而不是实际的最后一个标签。

这是我的 x 轴选项

xAxis: {
    type: 'Month',
    // tickInterval is 5 this time
    tickInterval: <?php echo number_format($num_results/5, 0);?>,
    endOnTick: true, // it shows "25" at the end of the label. not "2019-06"
    showLastLabel: true, // Default is true though..
    labels: {
        autoRotation: 0
    },
    //I get those categories from server
    //so it could be different every time
    //but this time I just write the result of it.
    categories:  ["2017-07","2017-08","2017-09","2017-10","2017-11","2017-12","2018-01","2018-02","2018-03","2018-04","2018-05","2018-06","2018-07","2018-08","2018-09","2018-10","2018-11","2018-12","2019-01","2019-02","2019-03","2019-04","2019-05","2019-06"]
}

预期的 x 轴标签是“2017-07 2017-12 2018-05 2018-10 2019-03 2019-06”

实际结果是“2017-07 2017-12 2018-05 2018-10 2019-03 25”

Answer 1

啊，我使用了tickPositioner并解决了它!

xAxis: {
    type: 'Linear',
    tickmarkPlacement: 'on',
    tickPositioner: function() {
        var positions = [],
            ext = this.getExtremes(),
            xMax = Math.round(ext.max),
            xMin = Math.round(ext.min);

        for (var i = xMin; i < xMax; i++) {
            if (i % <?php echo number_format($num_results/3,0);?> == 0) {
                positions.push(i);
            }
        }
        positions.push(xMax);
        return positions;
    },
    labels: {
        autoRotation: 0,
    },
    categories:  ["2017-07","2017-08","2017-09","2017-10","2017-11","2017-12","2018-01","2018-02","2018-03","2018-04","2018-05","2018-06","2018-07","2018-08","2018-09","2018-10","2018-11","2018-12","2019-01","2019-02","2019-03","2019-04","2019-05","2019-06"]
}