修复ChartJS值显示不正确的问题

时间:2019-03-04 13:08:20

标签: chart.js

如何使ChartJS缩放到比最大值略大一点,以正确显示高于最高条的值?

enter image description here

第二个值(14)在此显示一半,第三个值(15)甚至不显示。

代码如下:

var ctx = document.getElementById('chart-hour');
var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ['09h - 10h', '10h - 11h', '11h - 12h', '12h - 13h', '13h - 14h', 'PAUSE DEJ', '15h - 16h', '16h - 17h', '17h - 18h'],
        datasets: [{
            label: '',
            data: [0,14,15,7,1,0,0,0,0],
            backgroundColor: [
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)',
                'rgba(54, 162, 235, 0.6)'
            ],
            borderColor: [
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(54, 162, 235, 1)'
            ],
            borderWidth: 1
        }]
    },
    options: {
        legend: {
            display: false
        },
        responsive: true,
        maintainAspectRatio: false,
        scales: {
            yAxes: [{
                ticks: {
                    beginAtZero: true
                }
            }]
        }
    }
});

和用于显示值的插件:

Chart.plugins.register({
    afterDatasetsDraw: function(chart) {
        var ctx = chart.ctx;

        chart.data.datasets.forEach(function(dataset, i) {
            var meta = chart.getDatasetMeta(i);
            if (!meta.hidden) {
                meta.data.forEach(function(element, index) {
                    // Draw the text in black, with the specified font
                    ctx.fillStyle = 'rgb(20, 20, 20)';

                    var fontSize = 15;
                    var fontStyle = 'normal';
                    var fontFamily = 'Montserrat';
                    ctx.font = Chart.helpers.fontString(fontSize, fontStyle, fontFamily);

                    // Just naively convert to string for now
                    var dataString = dataset.data[index].toString();

                    // Make sure alignment settings are correct
                    ctx.textAlign = 'center';
                    ctx.textBaseline = 'bottom';

                    var padding = 0;
                    var position = element.tooltipPosition();
                    ctx.fillText(dataString, position.x, position.y - (fontSize / 2) - padding);
                });
            }
        });
    }
});

1 个答案:

答案 0 :(得分:0)

好吧,我找到了一种方法:

将值放入数组中并获得最大值。

然后,如果最大值为0,则在yAxes中设置max: 10

如果最大值大于0,则将最大值加10,将其放入变量中,然后将其传递给max: