如何在图表上显示数据值.js
2022-08-30 02:59:01
Chart.js 2.7.0+有一个官方插件可以做到这一点:Datalabels
否则,您可以在动画完成上循环遍历点/条形并显示值
预览
断续器
<canvas id="myChart1" height="300" width="500"></canvas>
<canvas id="myChart2" height="300" width="500"></canvas>
脚本
var chartData = {
labels: ["January", "February", "March", "April", "May", "June"],
datasets: [
{
fillColor: "#79D1CF",
strokeColor: "#79D1CF",
data: [60, 80, 81, 56, 55, 40]
}
]
};
var ctx = document.getElementById("myChart1").getContext("2d");
var myLine = new Chart(ctx).Line(chartData, {
showTooltips: false,
onAnimationComplete: function () {
var ctx = this.chart.ctx;
ctx.font = this.scale.font;
ctx.fillStyle = this.scale.textColor
ctx.textAlign = "center";
ctx.textBaseline = "bottom";
this.datasets.forEach(function (dataset) {
dataset.points.forEach(function (points) {
ctx.fillText(points.value, points.x, points.y - 10);
});
})
}
});
var ctx = document.getElementById("myChart2").getContext("2d");
var myBar = new Chart(ctx).Bar(chartData, {
showTooltips: false,
onAnimationComplete: function () {
var ctx = this.chart.ctx;
ctx.font = this.scale.font;
ctx.fillStyle = this.scale.textColor
ctx.textAlign = "center";
ctx.textBaseline = "bottom";
this.datasets.forEach(function (dataset) {
dataset.bars.forEach(function (bar) {
ctx.fillText(bar.value, bar.x, bar.y - 5);
});
})
}
});
这适用于图表.js 2.3,包括两种线/柱线类型。
重要:即使不需要动画,也不要将持续时间选项更改为 0。否则,你会得到 chartInstance.controller is undefined error。
var chartData = {
labels: ["January", "February", "March", "April", "May", "June"],
datasets: [
{
fillColor: "#79D1CF",
strokeColor: "#79D1CF",
data: [60, 80, 81, 56, 55, 40]
}
]
};
var opt = {
events: false,
tooltips: {
enabled: false
},
hover: {
animationDuration: 0
},
animation: {
duration: 1,
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);
});
});
}
}
};
var ctx = document.getElementById("Chart1"),
myLineChart = new Chart(ctx, {
type: 'bar',
data: chartData,
options: opt
});
<canvas id="myChart1" height="300" width="500"></canvas>