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javascript - 使用 Chart.js 显示图表

转载 作者:行者123 更新时间:2023-11-28 20:08:19 25 4
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我对 JavaScript 和 HTML5 还很陌生。我正在尝试使用 Chart.js 将普通折线图打印到 Canvas 上。我按照他们网站上的分步指南进行操作,但无法显示图表。

这是当前代码:

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>CHARTS</title>
<script src="../../../Downloads/Chart.js-master/Chart.js"></script>
</head>

<body>
<canvas id="myCanvas" width="800" height="500" style="border:dashed #FF0000">Aw Snap!</canvas>

<script>
context = document.getElementById('myCanvas').getContext('2d');

var data = {
labels : ["January","February","March","April","May","June","July"],
datasets : [
{
fillColor : "rgba(220,220,220,0.5)",
strokeColor : "rgba(220,220,220,1)",
pointColor : "rgba(220,220,220,1)",
pointStrokeColor : "#fff",
data : [65,59,90,81,56,55,40]
},
{
fillColor : "rgba(151,187,205,0.5)",
strokeColor : "rgba(151,187,205,1)",
pointColor : "rgba(151,187,205,1)",
pointStrokeColor : "#fff",
data : [28,48,40,19,96,27,100]
}
]
}
Line.defaults = {

//Boolean - If we show the scale above the chart data
scaleOverlay : false,

//Boolean - If we want to override with a hard coded scale
scaleOverride : false,

//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps : null,
//Number - The value jump in the hard coded scale
scaleStepWidth : null,
//Number - The scale starting value
scaleStartValue : null,

//String - Colour of the scale line
scaleLineColor : "rgba(0,0,0,.1)",

//Number - Pixel width of the scale line
scaleLineWidth : 1,

//Boolean - Whether to show labels on the scale
scaleShowLabels : true,

//Interpolated JS string - can access value
scaleLabel : "<%=value%>",

//String - Scale label font declaration for the scale label
scaleFontFamily : "'Arial'",

//Number - Scale label font size in pixels
scaleFontSize : 12,

//String - Scale label font weight style
scaleFontStyle : "normal",

//String - Scale label font colour
scaleFontColor : "#666",

///Boolean - Whether grid lines are shown across the chart
scaleShowGridLines : true,

//String - Colour of the grid lines
scaleGridLineColor : "rgba(0,0,0,.05)",

//Number - Width of the grid lines
scaleGridLineWidth : 1,

//Boolean - Whether the line is curved between points
bezierCurve : true,

//Boolean - Whether to show a dot for each point
pointDot : true,

//Number - Radius of each point dot in pixels
pointDotRadius : 3,

//Number - Pixel width of point dot stroke
pointDotStrokeWidth : 1,

//Boolean - Whether to show a stroke for datasets
datasetStroke : true,

//Number - Pixel width of dataset stroke
datasetStrokeWidth : 2,

//Boolean - Whether to fill the dataset with a colour
datasetFill : true,

//Boolean - Whether to animate the chart
animation : true,

//Number - Number of animation steps
animationSteps : 60,

//String - Animation easing effect
animationEasing : "easeOutQuart",

//Function - Fires when the animation is complete
onAnimationComplete : null

}

new Chart(context).Line(data,options);

</script>

</body>

我做错了什么导致我的图表无法显示?

最佳答案

当您调用“new Chart”时,数据变量尚未初始化。将“新图表”移动到 JS block 的末尾。

提示 - 使用 JS 控制台检查错误。

编辑:还有两个额外的 JavaScript 错误 - options 变量未初始化,Line 是 undefined variable 。请查看我下面的回复以获取演示链接。

关于javascript - 使用 Chart.js 显示图表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20380611/

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