javascript - 图表在完成动画后立即消失

Question

我正在尝试使用 chartjs，所以我从 official document 复制了示例代码像这样。

<canvas id="myChart" width="400" height="400"></canvas>
<script>
 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]
 }
   ]
 }
 //Get the context of the canvas element we want to select
 var ctx = document.getElementById("myChart").getContext("2d");
 var myNewChart = new Chart(ctx).PolarArea(data);
 new Chart(ctx).Line(data);
</script>

示例:http://jsfiddle.net/DerekL/FZW9z/

图表首先出现，但当第一个动画结束时它就消失了。Javascript 控制台什么都不显示。当一个选项 animation 被定义为 false 时，它只会瞬间出现并同样消失。

我在 Mac 中尝试了 Firefox 和 Chrome，但结果是一样的。

它是如何发生的，我该如何解决？

Answer 1

您实际上调用了 new Chart() 两次。请看下面的代码。我连接了不需要的线路。另请参阅更新的 JSFiddle http://jsfiddle.net/sajith/VW4U5/

<canvas id="myChart" width="400" height="400"></canvas>
<script>
 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]
 }
   ]
 }
 //Get the context of the canvas element we want to select
 var ctx = document.getElementById("myChart").getContext("2d");
 //var myNewChart = new Chart(ctx).PolarArea(data);
 new Chart(ctx).Line(data);
</script>