在条形图的顶部显示计数-ChartJS

Question

在Chart.js中的我的选项对象中

我已经尝试过

plugins: {
    afterDatasetsDraw: function (context, easing) {
        var ctx = context.chart.ctx;
        context.data.datasets.forEach(function (dataset) {
            for (var i = 0; i < dataset.data.length; i++) {
                if (dataset.data[i] != 0) {
                    var model = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._model;
                    var textY = model.y + (dataset.type == "line" ? -3 : 15);

                    ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontSize, 'normal', Chart.defaults.global.defaultFontFamily);
                    ctx.textAlign = 'start';
                    ctx.textBaseline = 'middle';
                    ctx.fillStyle = dataset.type == "line" ? "black" : "black";
                    ctx.save();
                    ctx.translate(model.x, textY-15);
                    ctx.rotate(4.7);
                    ctx.fillText(dataset.data[i], 0, 0);
                    ctx.restore();
                }
            }
        });
    }

}

我没有运气。

---

尽管，我已经尝试过了，但是有效

animation: {
    duration: ,
    onComplete: function() {
        var chartInstance = this.chart,
        ctx = chartInstance.ctx;

        ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontSize, Chart.defaults.global.defaultFontStyle, Chart.defaults.global.defaultFontFamily);
        ctx.textAlign = 'center';
        ctx.textBaseline = 'bottom';

        this.data.datasets.forEach(function(dataset, i) {
            var meta = chartInstance.controller.getDatasetMeta(i);
            meta.data.forEach(function(bar, index) {
                var data = dataset.data[index];
                ctx.fillText(data, bar._model.x, bar._model.y - 5);
            });
        });
    }
}

它似乎得到了我想要的东西，但是当我将其悬停在它上面时，它会闪烁并显得非常有故障。

https://i.imgur.com/HKVXNXu.gif

你们知道更好的方法吗？

Answer 1

[https://chartjs-plugin-datalabels.netlify.com/，此options用于标签：

• anchor:'end', ==>最高元素边界

[align: top ==>标签位于锚点之后，沿着相同的方向

要进行微调，请更改padding，offset（负或正），字体大小等（很多控件）。 datalabels Options

“ Hello world example”：

// Change default options for ALL charts
Chart.helpers.merge(Chart.defaults.global.plugins.datalabels, {
  opacity: 1,
  color: 'black',
  borderColor: '#11469e', 
  anchor: 'end', /*https://chartjs-plugin-datalabels.netlify.com/guide/positioning.html */
  align: 'top', /* https://chartjs-plugin-datalabels.netlify.com/guide/positioning.html#alignment-and-offset */
  font: {
    weight: 'bold',
    size: 14,
    lineHeight: 1 /* align v center */
  },
  offset: 1, /* 4 by deafult */
  padding:{
    bottom: 0 /* 4 by deafult */
  }
});

var data = {
  labels: ["Africa", "Asia", "Europe", "America"],
  datasets: [{
    /* data */
    label: "Population (millions)",
    backgroundColor: ["#490A3D", "#BD1550","#E97F02", '#F8CA00'],
    data: [1000,1500,2000, 2200]
  }]
};

var options = {
  plugins: {
    // Change options for ALL labels of THIS CHART
    datalabels: {

    }
  },
  animation:{
    duration: 2000 /* time in ms */
  },
  scales: {
    xAxes: [{
      stacked: true
    }],
    yAxes: [{
      stacked: true
    }]
  }
};

var myChart = new Chart(document.getElementById("chart"), {
  type: 'bar',
  data: data,
  options: options
});

<canvas id="chart"></canvas>

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]"></script>