动态更新 chartjs 图表的值

我使用 chartjs 创建了一个基本的条形图,它工作得很好。现在我想按时间间隔更新这些值。我的问题是,在我创建了图表之后,我不知道如何正确地更新它的值..。

我的代码:

var ctx = $("#myChart").get(0).getContext("2d");


var dts = [
{
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,1)",
data: [0, 0, 0, 0, 0]
}
];


var data = {
labels: ["Core#1", "Core#2", "Core#3", "Core#4", "Total"],
datasets: dts
};


var chart = new Chart(ctx);
chart.Bar(data);


//test code
setInterval( function () {
data.datasets[0].data = [random(), random(), random(), random(), random()];
chart.Bar(data);


},2000);

在测试代码中,我用 datasets[0].data来更新值-这是正确的方法吗?这样做的问题在于,每次调用 chart.Bar()时,这些值都会被重置为0,然后被动画化为随机值(就像重新创建图表一样)。这样,所有的动画总是从0到值,这看起来很奇怪。我希望,如果我更新一个值从50到10的酒吧将下降到10从50,而不是设置为0然后动画到10。

我在文件里没有找到任何关于这个的东西... ... 是我做错了什么,还是这个图书馆不可能做到?

430210 次浏览

我觉得现在不可能。

然而,正如作者在这里暗示的那样,这是一个应该很快就会出现的特性: Https://github.com/nnnick/chart.js/issues/161#issuecomment-20487775

更新: 看起来 Chartjs 已经更新了(见下面的评论):

  1. 下面是使用新数据更新线图的示例: http://jsbin.com/yitep/5/edit
  2. 下面是我们如何更新线性图表上的现有数据: http://jsbin.com/yitep/4/edit

原文

截至2013年11月,更新图表的选择似乎很少。

有一个 举个好例子(复制下面)添加新的点到一个线图。还是有点神经质,不过还不错。然而,我认为效果可能取决于您使用的图表。

这看起来像是在开发过程中的某个地方。但我还没有看到任何发布日期的迹象: https://github.com/nnnick/Chart.js/issues/13[2014年7月26日关闭]

JS

$(document).ready(function(){
var count = 10;
var data = {
labels : ["1","2","3","4","5", "6", "7", "8", "9", "10"],
datasets : [
{
fillColor : "rgba(220,220,220,0.5)",
strokeColor : "rgba(220,220,220,1)",
pointColor : "rgba(220,220,220,1)",
pointStrokeColor : "#fff",
data : [65,59,90,81,56,45,30,20,3,37]
},
{
fillColor : "rgba(151,187,205,0.5)",
strokeColor : "rgba(151,187,205,1)",
pointColor : "rgba(151,187,205,1)",
pointStrokeColor : "#fff",
data : [28,48,40,19,96,87,66,97,92,85]
}
]
}
// this is ugly, don't judge me
var updateData = function(oldData){
var labels = oldData["labels"];
var dataSetA = oldData["datasets"][0]["data"];
var dataSetB = oldData["datasets"][1]["data"];


labels.shift();
count++;
labels.push(count.toString());
var newDataA = dataSetA[9] + (20 - Math.floor(Math.random() * (41)));
var newDataB = dataSetB[9] + (20 - Math.floor(Math.random() * (41)));
dataSetA.push(newDataA);
dataSetB.push(newDataB);
dataSetA.shift();
dataSetB.shift();    };


var optionsAnimation = {
//Boolean - If we want to override with a hard coded scale
scaleOverride : true,
//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps : 10,
//Number - The value jump in the hard coded scale
scaleStepWidth : 10,
//Number - The scale starting value
scaleStartValue : 0
}


// Not sure why the scaleOverride isn't working...
var optionsNoAnimation = {
animation : false,
//Boolean - If we want to override with a hard coded scale
scaleOverride : true,
//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps : 20,
//Number - The value jump in the hard coded scale
scaleStepWidth : 10,
//Number - The scale starting value
scaleStartValue : 0
}


//Get the context of the canvas element we want to select
var ctx = document.getElementById("myChart").getContext("2d");
var optionsNoAnimation = {animation : false}
var myNewChart = new Chart(ctx);
myNewChart.Line(data, optionsAnimation);


setInterval(function(){
updateData(data);
myNewChart.Line(data, optionsNoAnimation)
;}, 2000
);
});




// ChartJS
var Chart=function(s){function v(a,c,b){a=A((a-c.graphMin)/(c.steps*c.stepValue),1,0);return b*c.steps*a}function x(a,c,b,e){function h(){g+=f;var k=a.animation?A(d(g),null,0):1;e.clearRect(0,0,q,u);a.scaleOverlay?(b(k),c()):(c(),b(k));if(1>=g)D(h);else if("function"==typeof a.onAnimationComplete)a.onAnimationComplete()}var f=a.animation?1/A(a.animationSteps,Number.MAX_VALUE,1):1,d=B[a.animationEasing],g=a.animation?0:1;"function"!==typeof c&&(c=function(){});D(h)}function C(a,c,b,e,h,f){var d;a=
Math.floor(Math.log(e-h)/Math.LN10);h=Math.floor(h/(1*Math.pow(10,a)))*Math.pow(10,a);e=Math.ceil(e/(1*Math.pow(10,a)))*Math.pow(10,a)-h;a=Math.pow(10,a);for(d=Math.round(e/a);d<b||d>c;)a=d<b?a/2:2*a,d=Math.round(e/a);c=[];z(f,c,d,h,a);return{steps:d,stepValue:a,graphMin:h,labels:c}}function z(a,c,b,e,h){if(a)for(var f=1;f<b+1;f++)c.push(E(a,{value:(e+h*f).toFixed(0!=h%1?h.toString().split(".")[1].length:0)}))}function A(a,c,b){return!isNaN(parseFloat(c))&&isFinite(c)&&a>c?c:!isNaN(parseFloat(b))&&
isFinite(b)&&a<b?b:a}function y(a,c){var b={},e;for(e in a)b[e]=a[e];for(e in c)b[e]=c[e];return b}function E(a,c){var b=!/\W/.test(a)?F[a]=F[a]||E(document.getElementById(a).innerHTML):new Function("obj","var p=[],print=function(){p.push.apply(p,arguments);};with(obj){p.push('"+a.replace(/[\r\t\n]/g," ").split("<%").join("\t").replace(/((^|%>)[^\t]*)'/g,"$1\r").replace(/\t=(.*?)%>/g,"',$1,'").split("\t").join("');").split("%>").join("p.push('").split("\r").join("\\'")+"');}return p.join('');");return c?
b(c):b}var r=this,B={linear:function(a){return a},easeInQuad:function(a){return a*a},easeOutQuad:function(a){return-1*a*(a-2)},easeInOutQuad:function(a){return 1>(a/=0.5)?0.5*a*a:-0.5*(--a*(a-2)-1)},easeInCubic:function(a){return a*a*a},easeOutCubic:function(a){return 1*((a=a/1-1)*a*a+1)},easeInOutCubic:function(a){return 1>(a/=0.5)?0.5*a*a*a:0.5*((a-=2)*a*a+2)},easeInQuart:function(a){return a*a*a*a},easeOutQuart:function(a){return-1*((a=a/1-1)*a*a*a-1)},easeInOutQuart:function(a){return 1>(a/=0.5)?
0.5*a*a*a*a:-0.5*((a-=2)*a*a*a-2)},easeInQuint:function(a){return 1*(a/=1)*a*a*a*a},easeOutQuint:function(a){return 1*((a=a/1-1)*a*a*a*a+1)},easeInOutQuint:function(a){return 1>(a/=0.5)?0.5*a*a*a*a*a:0.5*((a-=2)*a*a*a*a+2)},easeInSine:function(a){return-1*Math.cos(a/1*(Math.PI/2))+1},easeOutSine:function(a){return 1*Math.sin(a/1*(Math.PI/2))},easeInOutSine:function(a){return-0.5*(Math.cos(Math.PI*a/1)-1)},easeInExpo:function(a){return 0==a?1:1*Math.pow(2,10*(a/1-1))},easeOutExpo:function(a){return 1==
a?1:1*(-Math.pow(2,-10*a/1)+1)},easeInOutExpo:function(a){return 0==a?0:1==a?1:1>(a/=0.5)?0.5*Math.pow(2,10*(a-1)):0.5*(-Math.pow(2,-10*--a)+2)},easeInCirc:function(a){return 1<=a?a:-1*(Math.sqrt(1-(a/=1)*a)-1)},easeOutCirc:function(a){return 1*Math.sqrt(1-(a=a/1-1)*a)},easeInOutCirc:function(a){return 1>(a/=0.5)?-0.5*(Math.sqrt(1-a*a)-1):0.5*(Math.sqrt(1-(a-=2)*a)+1)},easeInElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(1==(a/=1))return 1;b||(b=0.3);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*
Math.PI)*Math.asin(1/e);return-(e*Math.pow(2,10*(a-=1))*Math.sin((1*a-c)*2*Math.PI/b))},easeOutElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(1==(a/=1))return 1;b||(b=0.3);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*Math.PI)*Math.asin(1/e);return e*Math.pow(2,-10*a)*Math.sin((1*a-c)*2*Math.PI/b)+1},easeInOutElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(2==(a/=0.5))return 1;b||(b=1*0.3*1.5);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*Math.PI)*Math.asin(1/e);return 1>a?-0.5*e*Math.pow(2,10*
(a-=1))*Math.sin((1*a-c)*2*Math.PI/b):0.5*e*Math.pow(2,-10*(a-=1))*Math.sin((1*a-c)*2*Math.PI/b)+1},easeInBack:function(a){return 1*(a/=1)*a*(2.70158*a-1.70158)},easeOutBack:function(a){return 1*((a=a/1-1)*a*(2.70158*a+1.70158)+1)},easeInOutBack:function(a){var c=1.70158;return 1>(a/=0.5)?0.5*a*a*(((c*=1.525)+1)*a-c):0.5*((a-=2)*a*(((c*=1.525)+1)*a+c)+2)},easeInBounce:function(a){return 1-B.easeOutBounce(1-a)},easeOutBounce:function(a){return(a/=1)<1/2.75?1*7.5625*a*a:a<2/2.75?1*(7.5625*(a-=1.5/2.75)*
a+0.75):a<2.5/2.75?1*(7.5625*(a-=2.25/2.75)*a+0.9375):1*(7.5625*(a-=2.625/2.75)*a+0.984375)},easeInOutBounce:function(a){return 0.5>a?0.5*B.easeInBounce(2*a):0.5*B.easeOutBounce(2*a-1)+0.5}},q=s.canvas.width,u=s.canvas.height;window.devicePixelRatio&&(s.canvas.style.width=q+"px",s.canvas.style.height=u+"px",s.canvas.height=u*window.devicePixelRatio,s.canvas.width=q*window.devicePixelRatio,s.scale(window.devicePixelRatio,window.devicePixelRatio));this.PolarArea=function(a,c){r.PolarArea.defaults={scaleOverlay:!0,
scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleShowLine:!0,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowLabelBackdrop:!0,scaleBackdropColor:"rgba(255,255,255,0.75)",scaleBackdropPaddingY:2,scaleBackdropPaddingX:2,segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",
animateRotate:!0,animateScale:!1,onAnimationComplete:null};var b=c?y(r.PolarArea.defaults,c):r.PolarArea.defaults;return new G(a,b,s)};this.Radar=function(a,c){r.Radar.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleShowLine:!0,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!1,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowLabelBackdrop:!0,scaleBackdropColor:"rgba(255,255,255,0.75)",
scaleBackdropPaddingY:2,scaleBackdropPaddingX:2,angleShowLineOut:!0,angleLineColor:"rgba(0,0,0,.1)",angleLineWidth:1,pointLabelFontFamily:"'Arial'",pointLabelFontStyle:"normal",pointLabelFontSize:12,pointLabelFontColor:"#666",pointDot:!0,pointDotRadius:3,pointDotStrokeWidth:1,datasetStroke:!0,datasetStrokeWidth:2,datasetFill:!0,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Radar.defaults,c):r.Radar.defaults;return new H(a,b,s)};this.Pie=function(a,
c){r.Pie.defaults={segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",animateRotate:!0,animateScale:!1,onAnimationComplete:null};var b=c?y(r.Pie.defaults,c):r.Pie.defaults;return new I(a,b,s)};this.Doughnut=function(a,c){r.Doughnut.defaults={segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,percentageInnerCutout:50,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",animateRotate:!0,animateScale:!1,
onAnimationComplete:null};var b=c?y(r.Doughnut.defaults,c):r.Doughnut.defaults;return new J(a,b,s)};this.Line=function(a,c){r.Line.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowGridLines:!0,scaleGridLineColor:"rgba(0,0,0,.05)",scaleGridLineWidth:1,bezierCurve:!0,
pointDot:!0,pointDotRadius:4,pointDotStrokeWidth:2,datasetStroke:!0,datasetStrokeWidth:2,datasetFill:!0,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Line.defaults,c):r.Line.defaults;return new K(a,b,s)};this.Bar=function(a,c){r.Bar.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",
scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowGridLines:!0,scaleGridLineColor:"rgba(0,0,0,.05)",scaleGridLineWidth:1,barShowStroke:!0,barStrokeWidth:2,barValueSpacing:5,barDatasetSpacing:1,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Bar.defaults,c):r.Bar.defaults;return new L(a,b,s)};var G=function(a,c,b){var e,h,f,d,g,k,j,l,m;g=Math.min.apply(Math,[q,u])/2;g-=Math.max.apply(Math,[0.5*c.scaleFontSize,0.5*c.scaleLineWidth]);
d=2*c.scaleFontSize;c.scaleShowLabelBackdrop&&(d+=2*c.scaleBackdropPaddingY,g-=1.5*c.scaleBackdropPaddingY);l=g;d=d?d:5;e=Number.MIN_VALUE;h=Number.MAX_VALUE;for(f=0;f<a.length;f++)a[f].value>e&&(e=a[f].value),a[f].value<h&&(h=a[f].value);f=Math.floor(l/(0.66*d));d=Math.floor(0.5*(l/d));m=c.scaleShowLabels?c.scaleLabel:null;c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(m,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(l,f,d,e,h,
m);k=g/j.steps;x(c,function(){for(var a=0;a<j.steps;a++)if(c.scaleShowLine&&(b.beginPath(),b.arc(q/2,u/2,k*(a+1),0,2*Math.PI,!0),b.strokeStyle=c.scaleLineColor,b.lineWidth=c.scaleLineWidth,b.stroke()),c.scaleShowLabels){b.textAlign="center";b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;var e=j.labels[a];if(c.scaleShowLabelBackdrop){var d=b.measureText(e).width;b.fillStyle=c.scaleBackdropColor;b.beginPath();b.rect(Math.round(q/2-d/2-c.scaleBackdropPaddingX),Math.round(u/2-k*(a+
1)-0.5*c.scaleFontSize-c.scaleBackdropPaddingY),Math.round(d+2*c.scaleBackdropPaddingX),Math.round(c.scaleFontSize+2*c.scaleBackdropPaddingY));b.fill()}b.textBaseline="middle";b.fillStyle=c.scaleFontColor;b.fillText(e,q/2,u/2-k*(a+1))}},function(e){var d=-Math.PI/2,g=2*Math.PI/a.length,f=1,h=1;c.animation&&(c.animateScale&&(f=e),c.animateRotate&&(h=e));for(e=0;e<a.length;e++)b.beginPath(),b.arc(q/2,u/2,f*v(a[e].value,j,k),d,d+h*g,!1),b.lineTo(q/2,u/2),b.closePath(),b.fillStyle=a[e].color,b.fill(),
c.segmentShowStroke&&(b.strokeStyle=c.segmentStrokeColor,b.lineWidth=c.segmentStrokeWidth,b.stroke()),d+=h*g},b)},H=function(a,c,b){var e,h,f,d,g,k,j,l,m;a.labels||(a.labels=[]);g=Math.min.apply(Math,[q,u])/2;d=2*c.scaleFontSize;for(e=l=0;e<a.labels.length;e++)b.font=c.pointLabelFontStyle+" "+c.pointLabelFontSize+"px "+c.pointLabelFontFamily,h=b.measureText(a.labels[e]).width,h>l&&(l=h);g-=Math.max.apply(Math,[l,1.5*(c.pointLabelFontSize/2)]);g-=c.pointLabelFontSize;l=g=A(g,null,0);d=d?d:5;e=Number.MIN_VALUE;
h=Number.MAX_VALUE;for(f=0;f<a.datasets.length;f++)for(m=0;m<a.datasets[f].data.length;m++)a.datasets[f].data[m]>e&&(e=a.datasets[f].data[m]),a.datasets[f].data[m]<h&&(h=a.datasets[f].data[m]);f=Math.floor(l/(0.66*d));d=Math.floor(0.5*(l/d));m=c.scaleShowLabels?c.scaleLabel:null;c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(m,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(l,f,d,e,h,m);k=g/j.steps;x(c,function(){var e=2*Math.PI/
a.datasets[0].data.length;b.save();b.translate(q/2,u/2);if(c.angleShowLineOut){b.strokeStyle=c.angleLineColor;b.lineWidth=c.angleLineWidth;for(var d=0;d<a.datasets[0].data.length;d++)b.rotate(e),b.beginPath(),b.moveTo(0,0),b.lineTo(0,-g),b.stroke()}for(d=0;d<j.steps;d++){b.beginPath();if(c.scaleShowLine){b.strokeStyle=c.scaleLineColor;b.lineWidth=c.scaleLineWidth;b.moveTo(0,-k*(d+1));for(var f=0;f<a.datasets[0].data.length;f++)b.rotate(e),b.lineTo(0,-k*(d+1));b.closePath();b.stroke()}c.scaleShowLabels&&
(b.textAlign="center",b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily,b.textBaseline="middle",c.scaleShowLabelBackdrop&&(f=b.measureText(j.labels[d]).width,b.fillStyle=c.scaleBackdropColor,b.beginPath(),b.rect(Math.round(-f/2-c.scaleBackdropPaddingX),Math.round(-k*(d+1)-0.5*c.scaleFontSize-c.scaleBackdropPaddingY),Math.round(f+2*c.scaleBackdropPaddingX),Math.round(c.scaleFontSize+2*c.scaleBackdropPaddingY)),b.fill()),b.fillStyle=c.scaleFontColor,b.fillText(j.labels[d],0,-k*(d+
1)))}for(d=0;d<a.labels.length;d++){b.font=c.pointLabelFontStyle+" "+c.pointLabelFontSize+"px "+c.pointLabelFontFamily;b.fillStyle=c.pointLabelFontColor;var f=Math.sin(e*d)*(g+c.pointLabelFontSize),h=Math.cos(e*d)*(g+c.pointLabelFontSize);b.textAlign=e*d==Math.PI||0==e*d?"center":e*d>Math.PI?"right":"left";b.textBaseline="middle";b.fillText(a.labels[d],f,-h)}b.restore()},function(d){var e=2*Math.PI/a.datasets[0].data.length;b.save();b.translate(q/2,u/2);for(var g=0;g<a.datasets.length;g++){b.beginPath();
b.moveTo(0,d*-1*v(a.datasets[g].data[0],j,k));for(var f=1;f<a.datasets[g].data.length;f++)b.rotate(e),b.lineTo(0,d*-1*v(a.datasets[g].data[f],j,k));b.closePath();b.fillStyle=a.datasets[g].fillColor;b.strokeStyle=a.datasets[g].strokeColor;b.lineWidth=c.datasetStrokeWidth;b.fill();b.stroke();if(c.pointDot){b.fillStyle=a.datasets[g].pointColor;b.strokeStyle=a.datasets[g].pointStrokeColor;b.lineWidth=c.pointDotStrokeWidth;for(f=0;f<a.datasets[g].data.length;f++)b.rotate(e),b.beginPath(),b.arc(0,d*-1*
v(a.datasets[g].data[f],j,k),c.pointDotRadius,2*Math.PI,!1),b.fill(),b.stroke()}b.rotate(e)}b.restore()},b)},I=function(a,c,b){for(var e=0,h=Math.min.apply(Math,[u/2,q/2])-5,f=0;f<a.length;f++)e+=a[f].value;x(c,null,function(d){var g=-Math.PI/2,f=1,j=1;c.animation&&(c.animateScale&&(f=d),c.animateRotate&&(j=d));for(d=0;d<a.length;d++){var l=j*a[d].value/e*2*Math.PI;b.beginPath();b.arc(q/2,u/2,f*h,g,g+l);b.lineTo(q/2,u/2);b.closePath();b.fillStyle=a[d].color;b.fill();c.segmentShowStroke&&(b.lineWidth=
c.segmentStrokeWidth,b.strokeStyle=c.segmentStrokeColor,b.stroke());g+=l}},b)},J=function(a,c,b){for(var e=0,h=Math.min.apply(Math,[u/2,q/2])-5,f=h*(c.percentageInnerCutout/100),d=0;d<a.length;d++)e+=a[d].value;x(c,null,function(d){var k=-Math.PI/2,j=1,l=1;c.animation&&(c.animateScale&&(j=d),c.animateRotate&&(l=d));for(d=0;d<a.length;d++){var m=l*a[d].value/e*2*Math.PI;b.beginPath();b.arc(q/2,u/2,j*h,k,k+m,!1);b.arc(q/2,u/2,j*f,k+m,k,!0);b.closePath();b.fillStyle=a[d].color;b.fill();c.segmentShowStroke&&
(b.lineWidth=c.segmentStrokeWidth,b.strokeStyle=c.segmentStrokeColor,b.stroke());k+=m}},b)},K=function(a,c,b){var e,h,f,d,g,k,j,l,m,t,r,n,p,s=0;g=u;b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;t=1;for(d=0;d<a.labels.length;d++)e=b.measureText(a.labels[d]).width,t=e>t?e:t;q/a.labels.length<t?(s=45,q/a.labels.length<Math.cos(s)*t?(s=90,g-=t):g-=Math.sin(s)*t):g-=c.scaleFontSize;d=c.scaleFontSize;g=g-5-d;e=Number.MIN_VALUE;h=Number.MAX_VALUE;for(f=0;f<a.datasets.length;f++)for(l=
0;l<a.datasets[f].data.length;l++)a.datasets[f].data[l]>e&&(e=a.datasets[f].data[l]),a.datasets[f].data[l]<h&&(h=a.datasets[f].data[l]);f=Math.floor(g/(0.66*d));d=Math.floor(0.5*(g/d));l=c.scaleShowLabels?c.scaleLabel:"";c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(l,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(g,f,d,e,h,l);k=Math.floor(g/j.steps);d=1;if(c.scaleShowLabels){b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;
for(e=0;e<j.labels.length;e++)h=b.measureText(j.labels[e]).width,d=h>d?h:d;d+=10}r=q-d-t;m=Math.floor(r/(a.labels.length-1));n=q-t/2-r;p=g+c.scaleFontSize/2;x(c,function(){b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(q-t/2+5,p);b.lineTo(q-t/2-r-5,p);b.stroke();0<s?(b.save(),b.textAlign="right"):b.textAlign="center";b.fillStyle=c.scaleFontColor;for(var d=0;d<a.labels.length;d++)b.save(),0<s?(b.translate(n+d*m,p+c.scaleFontSize),b.rotate(-(s*(Math.PI/180))),b.fillText(a.labels[d],
0,0),b.restore()):b.fillText(a.labels[d],n+d*m,p+c.scaleFontSize+3),b.beginPath(),b.moveTo(n+d*m,p+3),c.scaleShowGridLines&&0<d?(b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+d*m,5)):b.lineTo(n+d*m,p+3),b.stroke();b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(n,p+5);b.lineTo(n,5);b.stroke();b.textAlign="right";b.textBaseline="middle";for(d=0;d<j.steps;d++)b.beginPath(),b.moveTo(n-3,p-(d+1)*k),c.scaleShowGridLines?(b.lineWidth=c.scaleGridLineWidth,
b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+r+5,p-(d+1)*k)):b.lineTo(n-0.5,p-(d+1)*k),b.stroke(),c.scaleShowLabels&&b.fillText(j.labels[d],n-8,p-(d+1)*k)},function(d){function e(b,c){return p-d*v(a.datasets[b].data[c],j,k)}for(var f=0;f<a.datasets.length;f++){b.strokeStyle=a.datasets[f].strokeColor;b.lineWidth=c.datasetStrokeWidth;b.beginPath();b.moveTo(n,p-d*v(a.datasets[f].data[0],j,k));for(var g=1;g<a.datasets[f].data.length;g++)c.bezierCurve?b.bezierCurveTo(n+m*(g-0.5),e(f,g-1),n+m*(g-0.5),
e(f,g),n+m*g,e(f,g)):b.lineTo(n+m*g,e(f,g));b.stroke();c.datasetFill?(b.lineTo(n+m*(a.datasets[f].data.length-1),p),b.lineTo(n,p),b.closePath(),b.fillStyle=a.datasets[f].fillColor,b.fill()):b.closePath();if(c.pointDot){b.fillStyle=a.datasets[f].pointColor;b.strokeStyle=a.datasets[f].pointStrokeColor;b.lineWidth=c.pointDotStrokeWidth;for(g=0;g<a.datasets[f].data.length;g++)b.beginPath(),b.arc(n+m*g,p-d*v(a.datasets[f].data[g],j,k),c.pointDotRadius,0,2*Math.PI,!0),b.fill(),b.stroke()}}},b)},L=function(a,
c,b){var e,h,f,d,g,k,j,l,m,t,r,n,p,s,w=0;g=u;b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;t=1;for(d=0;d<a.labels.length;d++)e=b.measureText(a.labels[d]).width,t=e>t?e:t;q/a.labels.length<t?(w=45,q/a.labels.length<Math.cos(w)*t?(w=90,g-=t):g-=Math.sin(w)*t):g-=c.scaleFontSize;d=c.scaleFontSize;g=g-5-d;e=Number.MIN_VALUE;h=Number.MAX_VALUE;for(f=0;f<a.datasets.length;f++)for(l=0;l<a.datasets[f].data.length;l++)a.datasets[f].data[l]>e&&(e=a.datasets[f].data[l]),a.datasets[f].data[l]<
h&&(h=a.datasets[f].data[l]);f=Math.floor(g/(0.66*d));d=Math.floor(0.5*(g/d));l=c.scaleShowLabels?c.scaleLabel:"";c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(l,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(g,f,d,e,h,l);k=Math.floor(g/j.steps);d=1;if(c.scaleShowLabels){b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;for(e=0;e<j.labels.length;e++)h=b.measureText(j.labels[e]).width,d=h>d?h:d;d+=10}r=q-d-t;m=
Math.floor(r/a.labels.length);s=(m-2*c.scaleGridLineWidth-2*c.barValueSpacing-(c.barDatasetSpacing*a.datasets.length-1)-(c.barStrokeWidth/2*a.datasets.length-1))/a.datasets.length;n=q-t/2-r;p=g+c.scaleFontSize/2;x(c,function(){b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(q-t/2+5,p);b.lineTo(q-t/2-r-5,p);b.stroke();0<w?(b.save(),b.textAlign="right"):b.textAlign="center";b.fillStyle=c.scaleFontColor;for(var d=0;d<a.labels.length;d++)b.save(),0<w?(b.translate(n+
d*m,p+c.scaleFontSize),b.rotate(-(w*(Math.PI/180))),b.fillText(a.labels[d],0,0),b.restore()):b.fillText(a.labels[d],n+d*m+m/2,p+c.scaleFontSize+3),b.beginPath(),b.moveTo(n+(d+1)*m,p+3),b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+(d+1)*m,5),b.stroke();b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(n,p+5);b.lineTo(n,5);b.stroke();b.textAlign="right";b.textBaseline="middle";for(d=0;d<j.steps;d++)b.beginPath(),b.moveTo(n-3,p-(d+1)*
k),c.scaleShowGridLines?(b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+r+5,p-(d+1)*k)):b.lineTo(n-0.5,p-(d+1)*k),b.stroke(),c.scaleShowLabels&&b.fillText(j.labels[d],n-8,p-(d+1)*k)},function(d){b.lineWidth=c.barStrokeWidth;for(var e=0;e<a.datasets.length;e++){b.fillStyle=a.datasets[e].fillColor;b.strokeStyle=a.datasets[e].strokeColor;for(var f=0;f<a.datasets[e].data.length;f++){var g=n+c.barValueSpacing+m*f+s*e+c.barDatasetSpacing*e+c.barStrokeWidth*e;b.beginPath();
b.moveTo(g,p);b.lineTo(g,p-d*v(a.datasets[e].data[f],j,k)+c.barStrokeWidth/2);b.lineTo(g+s,p-d*v(a.datasets[e].data[f],j,k)+c.barStrokeWidth/2);b.lineTo(g+s,p);c.barShowStroke&&b.stroke();b.closePath();b.fill()}}},b)},D=window.requestAnimationFrame||window.webkitRequestAnimationFrame||window.mozRequestAnimationFrame||window.oRequestAnimationFrame||window.msRequestAnimationFrame||function(a){window.setTimeout(a,1E3/60)},F={}};

超文本标示语言

<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
</head>
<body>
<h1>Live Updating Chart.js</h1>


<canvas id="myChart" width="400" height="150"></canvas>




</body>
</html>

强 > update()触发图表的更新。 Chart.update ()

.update(config)

触发图表的更新。这可以在更新数据对象后安全地调用。这将更新所有的比例尺,图例,然后重新呈现图表。config对象可以与 附加配置一起提供用于更新过程。

在更新数据对象中一个或多个现有点的值之后,可以安全地调用 update(),在一个动画呈现循环中呈现更改。

// update the first dataset's value of 'March' to be 50
myBarChart.data.datasets[0].bars[2].value = 50;


// animate update of 'March' from 90 to 50.
myBarChart.update();

删除画布,然后再次添加。

function renderChart(label,data){


$("#canvas-wrapper").html("").html('<canvas id="storeSends"></canvas>');
var lineChartData = {
labels : label,
datasets : [
{
fillColor : "rgba(49, 195, 166, 0.2)",
strokeColor : "rgba(49, 195, 166, 1)",
pointColor : "rgba(49, 195, 166, 1)",
pointStrokeColor : "#fff",
data : data
}
]


}
var canvas = document.getElementById("storeSends");
var ctx = canvas.getContext("2d");


myLine = new Chart(ctx).Line(lineChartData, {
responsive: true,
maintainAspectRatio: false
});
}

您还可以使用 delete ()函数,如下所示

 if( window.myBar!==undefined)
window.myBar.destroy();
var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx).Bar(barChartData, {
responsive : true,
});

如此简单,只需替换图表画布元素。

$(’# 画布’) . replace With (’id = “画布”高度 = “200px”) 宽度 = “368px”>’) ;

以下是 ChartJs 最后一个版本中的操作方法:

setInterval(function(){
chart.data.datasets[0].data[5] = 80;
chart.data.labels[5] = "Newly Added";
chart.update();
}

看看这个 视频清晰

或者用 Jsfiddle测试

您只需要更改 chartObject.data.datasets值并像下面这样调用 update():

chartObject.data.datasets = newData.datasets;
chartObject.data.labels = newData.labels;
chartObject.update();

如果 delete ()和 clear ()不起作用(就像我的经验一样) ,您可以使用 jquery 删除画布并再次添加它。

    $('#chartAmazon').remove();
$('#chartBar').append('<canvas id="chartAmazon"></canvas>');


var ctxAmazon = $("#chartAmazon").get(0).getContext("2d");
var AmazonChart = new Chart(ctxAmazon, {
type: 'doughnut',
data: dataAmazon,
options: optionsA
});

最简单的方法是替换画布元素,然后再次调用 new Chart () :

function reloadMyChart() {
$('myChart').replaceWith('<canvas id="myChart"></canvas>');
new Chart(document.getElementById("myChart"), {
data: yourChartData,
type: yourChartType,
options: yourChartOptions
});
}

当然,必须用初始化 Chart.js 所需的正确值替换 ChartData、 ChartType 和 ChartOptions。

您可以在按钮单击或任何其他需要的事件上调用 reloadMyChart 函数。您可能会向这个函数添加参数,并使用这些参数进行 REST 调用来动态更新图表,如下所示:

function reloadMyChart(param1, param2) {
$('myChart').replaceWith('<canvas id="myChart"></canvas>');
$.get("restUrl?param1=" + param1 + "&param2=" + param2 + ",
function(data) {
// call new Chart() here and use returned data
}
);

希望能有所帮助! =)

我认为最简单的方法是写一个函数来更新你的图表,包括 chart.update()方法。查看我用 jsfiddle 为柱状图编写的 这个简单示例。

//value for x-axis
var emotions = ["calm", "happy", "angry", "disgust"];


//colours for each bar
var colouarray = ['red', 'green', 'yellow', 'blue'];


//Let's initialData[] be the initial data set
var initialData = [0.1, 0.4, 0.3, 0.6];


//Let's updatedDataSet[] be the array to hold the upadted data set with every update call
var updatedDataSet;


/*Creating the bar chart*/
var ctx = document.getElementById("barChart");
var barChart = new Chart(ctx, {
type: 'bar',
data: {
labels: emotions,
datasets: [{
backgroundColor: colouarray,
label: 'Prediction',
data: initialData
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true,
min: 0,
max: 1,
stepSize: 0.5,
}
}]
}
}
});


/*Function to update the bar chart*/
function updateBarGraph(chart, label, color, data) {
chart.data.datasets.pop();
chart.data.datasets.push({
label: label,
backgroundColor: color,
data: data
});
chart.update();
}


/*Updating the bar chart with updated data in every second. */
setInterval(function() {
updatedDataSet = [Math.random(), Math.random(), Math.random(), Math.random()];
updateBarGraph(barChart, 'Prediction', colouarray, updatedDataSet);
}, 1000);
<html>


<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.min.js"></script>


<body>
<div>
<h1>Update Bar Chart</h1>
<canvas id="barChart" width="800" height="450"></canvas>
</div>
<script src="barchart.js"></script>
</body>
  

</head>


</html>

希望这个能帮上忙。

显示实时更新图表

function add_data(chart, label, data)
{
var today = new Date();
var time = today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds();
myLineChart.data.datasets[0].data.push(Math.random() * 100);
myLineChart.data.datasets[1].data.push(Math.random() * 100);
myLineChart.data.labels.push(time)
myLineChart.update();
}
setInterval(add_data, 10000); //milisecond

完整的代码,你可以在描述链接下载

有两种方法可以解决这个问题:

  1. chart.update()

  2. 使用 chart.Delete ()删除现有图表并创建新的图表对象。

您可以使用 Chart.instances检查 Chart的实例。 这将为您提供所有的图表实例。 现在,您可以对该实例进行迭代,并更改配置中显示的数据。 假设您的页面中只有一个图表。

for (var _chartjsindex in Chart.instances) {
/*
* Here in the config your actual data and options which you have given at the
time of creating chart so no need for changing option only you can change data
*/
Chart.instances[_chartjsindex].config.data = [];
// here you can give add your data
Chart.instances[_chartjsindex].update();
// update will rewrite your whole chart with new value
}

这是 图表 Js-2.9.4的一个例子

var maximumPoints = 5;// with this variable you can decide how many points are display on the chart
function addData(chart, label, data) {
chart.data.labels.push(label);
chart.data.datasets.forEach((dataset) => {
var d = data[0];
dataset.data.push(d);
data.shift();
});




var canRemoveData = false;
chart.data.datasets.forEach((dataset) => {
if (dataset.data.length > maximumPoints) {


if (!canRemoveData) {
canRemoveData = true;
chart.data.labels.shift();
}


dataset.data.shift();


}


});






chart.update();
}








window.onload = function () {
var canvas = document.getElementById('elm-chart'),
ctx = canvas.getContext('2d');


var myLineChart = new Chart(ctx, {
type: 'line',
data: {
labels: [],
datasets: [
{
data: [],
label: 'Dataset-1',
backgroundColor: "#36a2eb88",
borderColor: "#36a2eb",
},
{
data: [],
label: 'Dataset-2',
backgroundColor: "#ff638488",
borderColor: "#ff6384",
}
],


},
options: {
responsive: false,
maintainAspectRatio: false,
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});


var index = 0;
setInterval(function () {


var data = [];
myLineChart.data.datasets.forEach((dataset) => {
data.push(Math.random() * 100);
});


addData(myLineChart, index, data);
index++;


}, 1000);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.min.js"></script>
<canvas id="elm-chart" width="640" height="480"></canvas>

从2022年开始,使用 ChartJS v3.7.1,您可以使用下面的代码。

请注意,它是基于 dou1ejack 的回答中的 JSBin 片段,但是这些片段没有更新,并且不适用于最新的 ChartJS 版本,主要是因为图表数据的路径改变了(现在是 yourChart._metasets[0]._dataset.data)。

var canvas = document.getElementById('updating-chart'),
ctx = canvas.getContext('2d'),
startingData = {
labels: [1, 2, 3, 4, 5, 6, 7],
datasets: [
{
fillColor: "rgba(220,220,220,0.2)",
strokeColor: "rgba(220,220,220,1)",
pointColor: "rgba(220,220,220,1)",
pointStrokeColor: "#fff",
data: [65, 59, 80, 81, 56, 55, 40]
},
{
fillColor: "rgba(151,187,205,0.2)",
strokeColor: "rgba(151,187,205,1)",
pointColor: "rgba(151,187,205,1)",
pointStrokeColor: "#fff",
data: [28, 48, 40, 19, 86, 27, 90]
}
]
};


// Reduce the animation steps for demo clarity.
const myLiveChart = new Chart(ctx, {
type: 'bar',
data: startingData,
options: {
scales: {
y: {
beginAtZero: true
}
},
maintainAspectRatio: false,
}
});


setInterval(function(){
// Get a random index point
var indexToUpdate = Math.round(Math.random() * startingData.labels.length);
  

// Update one of the points in the second dataset
myLiveChart._metasets[0]._dataset.data[indexToUpdate] = Math.random() * 100;
  

myLiveChart.update();
}, 5000);
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Updating chart example</title>
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
</head>
<body>
<canvas id="updating-chart" width="500" height="300"></canvas>
 

</body>
</html>

我的解决办法是将图表存储在 Vue 州以外的地方。将图表存储在 const 变量中,类似于 utility.js 文件。然后我就可以简单地这样做:

const PVR_CANVASES = {}


//This was my vue method for building the charts
build_metrics() {
this.votingResults.metrics.forEach(metric => {
const el = document.getElementById(metric.metric_data.canvas);
const n_chart = new Chart(el, {
type: 'line',
data: metric.chart.data,
options: {
responsive: true,
maintainAspectRatio: true,
layout: {
autoPadding: false
},
plugins: {
legend: {
display: false,
}
},
scales: {
x: {
display: false
},
y: {
display: false
}
},
elements: {
line: {
tension: 0.4
},
point: {
backgroundColor: 'rgba(0, 0, 0, 0.1)'
}
}
}
});
PVR_CANVASES[metric.chart.id] = n_chart;
})
}


//UPDATE CHART IS THIS SIMPLE
this.votingResults.metrics.forEach(metric => {
const n_chart = PVR_CANVASES[metric.chart.id];
n_chart.data = metric.chart.data;
n_chart.update();
});