ChartJS canvas not displaying rgba colors in IE, Safari and Firefox

问题

Im using ChartJS to display some data but it's not rendering the canvas element correctly in IE, Firefox and Safari.

My guess is that the background color property lacks any of the used prefixes for the other browser since it works fine in Chrome.

Anyone else had this issue?

Chrome:

Firefox, Safari and IE:

The code:

    window.onload = function() {
        var ctx = document.getElementById("canvas");
        var myChart = new Chart(ctx, {
            type: 'line',
            data: {
                labels: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug"],
                datasets: [{
                    label: '# of Value',
                    data: [12, 19, 3, 5, 2, 3, 10, 29],
                    backgroundColor: [
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)'
                    ],
                    borderColor: [
                        'rgba(33, 145, 81, 1)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)',
                        'rgba(33, 145, 81, 0.2)'
                    ],
                    borderWidth: 1
                }]
            },
            options: {
                scales: {
                    yAxes: [{
                        ticks: {
                            beginAtZero:true
                        }
                    }]
                }
            }
        });
    };
    });

回答1:

The problem is that you're giving the backgroundColor property an array of Color instead of a single one.

The line chart, with the fill property set to true needs to have only one Color, or else it will break like it does on your chart.

So you just need to change from :

backgroundColor: [
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)',
    'rgba(33, 145, 81, 0.2)'
],

To :

backgroundColor: 'rgba(33, 145, 81, 0.2)',

And it will give you this result whatever browser you are using.
(tests were done on IE 11 and Firefox 48)

回答2:

In my case, I was using rgb

backgroundColor: 'rgb(33, 145, 81, 0.2)',
borderColor: 'rgb(255, 134, 25, 1)',

Instead of rgba

backgroundColor: 'rgba(33, 145, 81, 0.2)',
borderColor: 'rgba(255, 134, 25, 1)',

来源：https://stackoverflow.com/questions/39332339/chartjs-canvas-not-displaying-rgba-colors-in-ie-safari-and-firefox

标签

javascript

canvas

chart.js

rgba