Question

请参阅小提琴URL：https://jsfiddle.net/vL0ta76w/

当前行为 Chart.js中的“点样式”属性提供了某些图标，例如圆形，三角形，矩形等，这些图标将显示在折线图上

var options = {
  type: 'line',
  data: {
    labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
    datasets: [
	    {
	      label: '# of Votes',
	      data: [12, -19, 3, 5, 2, 3],
      	borderWidth: 1,
        pointStyle:'triangle',
        pointRadius:'10',
        pointBackgroundColor:'red'
    	},	
		
		],
   pointStyle:'triangle'
  },
  options: {
  	scales: {
    	yAxes: [{
        ticks: {
					reverse: false
        }
      }]
    }
  }
}

var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);

canvas { background-color : #eee;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.js"></script>
<body>
    <canvas id="chartJSContainer" width="600" height="400"></canvas>
</body>

预期结果：

但是可以显示倒三角形吗？任何显示倒三角形或可插入的自定义图像的属性 通过该方法，如果数据集具有负值，我可以设法更改颜色。，但是在将图像反转或旋转180度时遇到问题

Answer 1

图表js允许提供pointStyle的数组而不是仅提供1。它还可以提供图像来代替预设的指针样式。

var image = document.getElementById('source');
var options = {
  type: 'line',
  data: {
    labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
    datasets: [{
        label: '# of Votes',
        data: [12, -19, 3, 5, 2, 3],
        borderWidth: 1,
        pointStyle: ['triangle', image, 'triangle', 'triangle', 'triangle', 'triangle'],
        pointRadius: '10',
        pointBackgroundColor: 'red'
      },

    ],
    pointStyle: 'triangle'
  },
  options: {
    scales: {
      yAxes: [{
        ticks: {
          reverse: false
        }
      }]
    }
  }
}

var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.js"></script>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<div style="display:none;">
  <img id="source" src="https://image.flaticon.com/icons/png/128/25/25224.png">
</div>

然后要使其动态化，可以在数据集中映射数据以生成pointerStyle数组

let pointerStyles = [12,-19,2,3,4].map(value=>{
 return value >=0 ? 'triangle' : 'other-triangle'
});

console.log(pointerStyles);

Line Chart.js中具有反转图像的点样式属性

1 个答案: