Chart.js 没有高度响应

Question

我有问题要让 chart.js 折线图对高度和宽度做出响应。

请参阅示例它应该如何工作：

• http://www.chartjs.org/samples/latest/charts/line/basic.html

这是我的代码：

  var randomScalingFactor = function(){ return Math.round(Math.random()*100)};
  var lineChartData = {
    labels : ['January','February','March','April','May','June','July'],
    datasets : [
      {
        label: 'My First dataset',
        labelColor : '#fff',
        fontColor : '#fff' ,
        backgroundColor : 'rgba(220,220,220,0.2)',
        borderColor : 'rgba(220,220,220,1)',
        pointBackgroundColor : 'rgba(220,220,220,1)',
        pointBorderColor : '#fff',
        data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
      }
    ]
  }

  var options = {
    maintainAspectRatio: false,
    legend: {
      display: false,
    },
    scales: {
      xAxes: [{
        gridLines: {
         display: false,
         color: '#03A5C5',
         lineWidth: 8,
         },
        ticks: {
          fontColor: "white",
        },
      }],
      yAxes: [{
        gridLines: {
         display: false,
         color: '#03A5C5',
         lineWidth: 8,
         },
        ticks: {
          fontColor: "white",
          beginAtZero: true,
        }
      }]
    }
  };
  var ctx = document.getElementById('canvas-1');
  var chart = new Chart(ctx, {
    responsive: true,
    type: 'line',
    data: lineChartData,
    options: options
  });

Answer 1

1. 创建班级

.chart-container {
    position: relative;
    margin: auto;
    height: 80vh;
    width: 80vw;
}

2. 使用类图表容器创建 Div 并在其中放置画布标签。

<div class="chart-container">
  <canvas id="canvas"></canvas>
</div>

3. 图表选项，使用属性maintainAspectRatio设置为 false：

options: {
    maintainAspectRatio: false,
    responsive: true,  
    ...
}

Answer 2

从Chart.js 的文档来看，建议将 canvas 包装到容器 div 中并更改容器的宽度/高度。但基本上它是通过给定的宽度或高度来改变的。

从lannymcnie找到了一个更灵活的自定义解决方案，可用于任何画布响应：

var stage = new createjs.Stage("canvas");

var c = new createjs.Shape();
c.graphics.f("#f00").dc(0,0,50); // Drawn a 100x100 circle from the center

var t = new createjs.Text("Resize the browser/frame to redraw", "24px Arial bold", "#000");
t.x = t.y = 20;
stage.addChild(c, t);

window.addEventListener("resize", handleResize);
function handleResize() {
    var w = window.innerWidth-2; // -2 accounts for the border
    var h = window.innerHeight-2;
    stage.canvas.width = w;
    stage.canvas.height = h;
    //
    var ratio = 100/100; // 100 is the width and height of the circle content.
    var windowRatio = w/h;
    var scale = w/100;
    if (windowRatio > ratio) {
        scale = h/100;
    }
    // Scale up to fit width or height
    c.scaleX= c.scaleY = scale; 
    
    // Center the shape
    c.x = w / 2;
    c.y = h / 2;
        
    stage.update();
}
       
handleResize(); // First draw

html, body {
    padding: 0; margin: 0;
    overflow:hidden;
}
canvas {
    border: 1px solid #f00;
}

<script src="https://code.createjs.com/easeljs-0.8.2.min.js"></script>
<canvas id="canvas" width="800" height="600"></canvas>