Chart.js 折线图未显示

Question

我用chart.js 构建了一个折线图。但是图表没有显示。这是我的 HTML

    <canvas id="myChart" width"600" height:"600"></canvas>

这是我的 javascript。这种方法我没有得到任何错误，但没有任何显示。

var c = $('#myChart');
var ct = c.get(0).getContext('2d');
var ctx = document.getElementById("myChart").getContext("2d").Line(data);


var data = {
labels: ["January", "February", "March", "April", "May", "June", "July","August", "November", "December"],
datasets: [
    {
        label: "Sodium intake",
        fillColor: "rgba(220,220,220,0.2)",
        strokeColor: "rgba(220,220,220,1)",
        pointColor: "rgba(220,220,220,1)",
        pointStrokeColor: "#fff",
        pointHighlightFill: "#fff",
        pointHighlightStroke: "rgba(220,220,220,1)",
        data: [165, 159, 180, 181, 156, 155, 140]
    },
    {
        label: "Sugar intake",
        fillColor: "rgba(151,187,205,0.2)",
        strokeColor: "rgba(151,187,205,1)",
        pointColor: "rgba(151,187,205,1)",
        pointStrokeColor: "#fff",
        pointHighlightFill: "#fff",
        pointHighlightStroke: "rgba(151,187,205,1)",
        data: [128, 148, 140, 119, 186, 127, 190]
    }
]

};

我使用的另一种方法类似于文档。我实例化了一个新图表。但是，这种方法为我的折线图返回未定义。

var ctx = document.getElementById("myChart").getContext("2d");
var myLineChart = new Chart(ctx).line(data,{
belzierCurve : false

});

Answer 1

在您的 html 上:

<canvas id="myChart" width"600" height:"600"></canvas>

它应该是:

<canvas id="myChart" width="600" height="600"></canvas>

然后，替换您的代码

var c = $('#myChart');
var ct = c.get(0).getContext('2d');
var ctx = document.getElementById("myChart").getContext("2d").Line(data);

有了这个代码

var ctx = new Chart(document.getElementById("myChart").getContext("2d")).Line(data);

所以在你的js中

var data = {
    //your data here
}
enter code here

然后在您的数据之后添加这一行

var ctx = new Chart(document.getElementById("myChart").getContext("2d")).Line(data);

所以你的代码看起来像这样:

var data = {
  labels: ["January", "February", "March", "April", "May", "June", "July","August", "November", "December"],
  datasets: [
      {
          label: "Sodium intake",
          fillColor: "rgba(220,220,220,0.2)",
          strokeColor: "rgba(220,220,220,1)",
          pointColor: "rgba(220,220,220,1)",
          pointStrokeColor: "#fff",
          pointHighlightFill: "#fff",
          pointHighlightStroke: "rgba(220,220,220,1)",
          data: [165, 159, 180, 181, 156, 155, 140]
      },
      {
          label: "Sugar intake",
          fillColor: "rgba(151,187,205,0.2)",
          strokeColor: "rgba(151,187,205,1)",
          pointColor: "rgba(151,187,205,1)",
          pointStrokeColor: "#fff",
          pointHighlightFill: "#fff",
          pointHighlightStroke: "rgba(151,187,205,1)",
          data: [128, 148, 140, 119, 186, 127, 190]
      }
  ]
}

var ctx = new Chart(document.getElementById("myChart").getContext("2d")).Line(data);