Javascript Charts.js:薄甜甜圈图表背景
我想创建一个浅灰色背景的油炸圈饼图 我发现创建它的唯一方法是添加第二个甜甜圈图表来创建背景 有什么方法能让它更简单吗 HTML: JavaScript:Javascript Charts.js:薄甜甜圈图表背景,javascript,charts,chart.js,Javascript,Charts,Chart.js,我想创建一个浅灰色背景的油炸圈饼图 我发现创建它的唯一方法是添加第二个甜甜圈图表来创建背景 有什么方法能让它更简单吗 HTML: JavaScript: var pointsUsed = [ { value: 44250, color: "#FF5F33", }, { value: 100000, color: "transparent", }, ]; var pointsUsedBg = [
var pointsUsed = [
{
value: 44250,
color: "#FF5F33",
},
{
value: 100000,
color: "transparent",
},
];
var pointsUsedBg = [
{
value: 100000,
color: "#EEEEEE",
},
];
var pointsUsed_ctx = document.getElementById("pointsUsed").getContext("2d");
var pointsUsedBg_ctx = document.getElementById("pointsUsedBg").getContext("2d");
var pointsUsed = new Chart(pointsUsed_ctx).Doughnut(pointsUsed, {
segmentShowStroke: false,
segmentStrokeWidth : 0,
percentageInnerCutout: 87,
showTooltips: false,
animationEasing: 'easeInOutCubic',
responsive: true
});
var pointsUsedBg = new Chart(pointsUsedBg_ctx).Doughnut(pointsUsedBg, {
segmentShowStroke: false,
segmentStrokeWidth : 0,
percentageInnerCutout: 94,
showTooltips: false,
animation: false,
responsive: true
});
谢谢 您可以扩展甜甜圈图表来实现这一点,如下所示
Chart.types.Doughnut.extend({
name: "DoughnutAlt",
initialize: function (data) {
// call the actual initialize
Chart.types.Doughnut.prototype.initialize.apply(this, arguments);
// save the actual clear method
var originalClear = this.clear;
// override the clear method to draw the background after each clear
this.clear = function () {
// call the original clear method first
originalClear.apply(this, arguments)
var ctx = this.chart.ctx;
// use any one of the segments to get the inner and outer radius and center x and y
var firstSegment = this.segments[0];
// adjust 0.3 to increaase / decrease the width of the background
var gap = (firstSegment.outerRadius - firstSegment.innerRadius) * (1 - 0.3) / 2;
// draw the background
ctx.save();
ctx.fillStyle = "#EEE";
ctx.beginPath();
ctx.arc(firstSegment.x, firstSegment.y, firstSegment.outerRadius - gap, 0, 2 * Math.PI);
ctx.arc(firstSegment.x, firstSegment.y, firstSegment.innerRadius + gap, 0, 2 * Math.PI, true);
ctx.closePath();
ctx.fill();
ctx.restore();
}
}
});
你会这样称呼它吗
var pointsUsed = new Chart(pointsUsed_ctx).DoughnutAlt(pointsUsed, {
...
小提琴-谢谢!工作得很有魅力D
Chart.types.Doughnut.extend({
name: "DoughnutAlt",
initialize: function (data) {
// call the actual initialize
Chart.types.Doughnut.prototype.initialize.apply(this, arguments);
// save the actual clear method
var originalClear = this.clear;
// override the clear method to draw the background after each clear
this.clear = function () {
// call the original clear method first
originalClear.apply(this, arguments)
var ctx = this.chart.ctx;
// use any one of the segments to get the inner and outer radius and center x and y
var firstSegment = this.segments[0];
// adjust 0.3 to increaase / decrease the width of the background
var gap = (firstSegment.outerRadius - firstSegment.innerRadius) * (1 - 0.3) / 2;
// draw the background
ctx.save();
ctx.fillStyle = "#EEE";
ctx.beginPath();
ctx.arc(firstSegment.x, firstSegment.y, firstSegment.outerRadius - gap, 0, 2 * Math.PI);
ctx.arc(firstSegment.x, firstSegment.y, firstSegment.innerRadius + gap, 0, 2 * Math.PI, true);
ctx.closePath();
ctx.fill();
ctx.restore();
}
}
});
var pointsUsed = new Chart(pointsUsed_ctx).DoughnutAlt(pointsUsed, {
...