我想在图表中设置最大水平线，如危险边界线
在上图中，我有一个折线图，我需要在其中设置类似蓝色的水平线.
我已经查看了ChartJS文档，但没有找到任何参考.
I have need to set same as below image
我想在图表中设置最大水平线，如危险边界线
在上图中，我有一个折线图，我需要在其中设置类似蓝色的水平线.
我已经查看了ChartJS文档，但没有找到任何参考.
I have need to set same as below image
看看这个图表.js插件
此链接提供:http://www.java2s.com/example/javascript/chart.js/draw-horizontal-lines-in-chartjs.html
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<script type="text/javascript" src="https://code.jquery.com/jquery-2.1.3.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.1.6/Chart.bundle.min.js"></script>
<script type="text/javascript">
$(window).load(function(){//from www . j a va 2 s . c o m
var canvas = document.getElementById("myChart");
var ctx = canvas.getContext("2d");
var horizonalLinePlugin = {
afterDraw: function(chartInstance) {
var yScale = chartInstance.scales["y-axis-0"];
var canvas = chartInstance.chart;
var ctx = canvas.ctx;
var index;
var line;
var style;
if (chartInstance.options.horizontalLine) {
for (index = 0; index < chartInstance.options.horizontalLine.length; index++) {
line = chartInstance.options.horizontalLine[index];
if (!line.style) {
style = "rgba(169,169,169, .6)";
} else {
style = line.style;
}
if (line.y) {
yValue = yScale.getPixelForValue(line.y);
} else {
yValue = 0;
}
ctx.lineWidth = 3;
if (yValue) {
ctx.beginPath();
ctx.moveTo(0, yValue);
ctx.lineTo(canvas.width, yValue);
ctx.strokeStyle = style;
ctx.stroke();
}
if (line.text) {
ctx.fillStyle = style;
ctx.fillText(line.text, 0, yValue + ctx.lineWidth);
}
}
return;
};
}
};
Chart.pluginService.register(horizonalLinePlugin);
var data = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [{
label: "My First dataset",
fill: false,
lineTension: 0.1,
backgroundColor: "rgba(75,192,192,0.4)",
borderColor: "rgba(75,192,192,1)",
borderCapStyle: 'butt',
borderDash: [],
borderDashOffset: 0.0,
borderJoinStyle: 'miter',
pointBorderColor: "rgba(75,192,192,1)",
pointBackgroundColor: "#fff",
pointBorderWidth: 1,
pointHoverRadius: 5,
pointHoverBackgroundColor: "rgba(75,192,192,1)",
pointHoverBorderColor: "rgba(220,220,220,1)",
pointHoverBorderWidth: 2,
pointRadius: 1,
pointHitRadius: 10,
data: [65, 59, 80, 81, 56, 55, 40],
}]
};
var myChart = new Chart(ctx, {
type: 'line',
data: data,
options: {
"horizontalLine": [{
"y": 82,
"style": "rgba(255, 0, 0, .4)",
"text": "max"
}, {
"y": 60,
"style": "#00ffff",
}, {
"y": 44,
"text": "min"
}]
}
});
});
</script>
</head>
<body>
<canvas id="myChart" width="400" height="400"></canvas>
</body>
</html>