如何用Chart.js显示折线图数据集点标签？ [英] How to display Line Chart dataset point labels with Chart.js?
问题描述
我有一个设计要求，显示一个包含5个趋势数据数据集的折线图。
I have a design requirement to display a line chart with 5 datasets of trends data. Each data value along the stroke lines need to be showing a data value label at its respective data point.
不幸的是，我在Charts.js中找不到一个能满足这个要求的选项这个要求。
Unfortunately, I cannot find an option within Charts.js that will satisfy this requirement.
有没有解决方法可以帮助我？
Is there a workaround that can help me out?
也： http://jsfiddle.net/s9eannLh/
非常感谢！
var data = {
labels: ["","Jun 2013","Jul 2013","Aug 2013","Sep 2013","Oct 2013","Nov 2013","Dec 2013","Jan 2014","Feb 2014","Mar 2014","Apr 2014","May 2014"],
datasets: [
{
label: "hemoglobin_1",
title: "test",
fillColor: "transparent",
strokeColor: "#65204c",
pointColor: "#65204c",
pointHighlightStroke: "#FFF",
data: [null,5.7,5.7,5.8,5.7,5.8,5.7,5.9,6.7,6.7,6.5,6.4,6.4]
},
{
label: "hemoglobin_2",
fillColor: "transparent",
strokeColor: "#ed7141",
pointColor: "#ed7141",
pointHighlightStroke: "#FFF",
data: [null,15.5,15.5,15.6,15.2,15.6,15.1,15.8,17,17.4,16.8,16.4,16.4]
},
{
label: "hemoglobin_3",
fillColor: "transparent",
strokeColor: "#de4760",
pointColor: "#de4760",
pointHighlightStroke: "#FFF",
data: [null,37.1,37,37.2,37.6,36.9,37.6,36.8,37.6,38,37.5,39.1,37.5]
},
{
label: "hemoglobin_4",
fillColor: "transparent",
strokeColor: "#fdcf7e",
pointColor: "#fdcf7e",
pointHighlightStroke: "#FFF",
data: [null,29.9,30.4,29.5,29.6,30.2,29.4,29.8,26.9,27,28.5,26.8,28.5]
},
{
label: "hemoglobin_5",
fillColor: "transparent",
strokeColor: "#a33a59",
pointColor: "#a33a59",
pointHighlightStroke: "#FFF",
data: [null,11.8,11.4,11.9,11.9,11.5,12.2,11.7,11.8,10.9,10.7,11.3,11.3]
}
]
};
var options = {
responsive: true,
scaleOverride: true,
scaleSteps: 10,
scaleStepWidth: 5,
scaleStartValue: 0,
showTooltips: false,
pointDot: true,
pointDotRadius : 6,
datasetStrokeWidth : 3,
bezierCurve : false,
scaleShowHorizontalLines: false,
scaleGridLineWidth : 2,
scaleGridLineColor : "#EEEEEE",
scaleLineWidth: 3,
scaleLineColor: "#000000",
scaleFontFamily: '"Gotham Book",sans-serif',
scaleFontSize: 18
}
var ctx = $("#myChart").get(0).getContext("2d");
var Trends = new Chart(ctx).Line(data, options);
推荐答案
我终于找到了这个问题的解决方案。
I was able to finally find the solution to this question.
我意识到我可以访问DOM中的图表对象：
I realized I had access to the chart object within the DOM:
Trends.datasets
在五个数据集中的每个数据集中都有一个包含x& y position：
Within each of the five datasets there was a points object containing x & y positions:
Trends.datasets[0..4].points
所以我通过使用Chart.js中的全局配置函数的回调来解析这些点：
So I parsed through the points with a callback utilizing the global configuration functions in Chart.js:
// Function - Will fire on animation progression.
onAnimationProgress: function(){},
// Function - Will fire on animation completion.
onAnimationComplete: function(){}
我发现我不得不使用 onAnimationComplete with responsive：true ，因为点标签会在resize事件上被擦除。
I found that I had to use onAnimationComplete with responsive: true because the point labels would get wiped out on a resize event.
一旦我在回调中找到了点，我就把我想要的标签写到画布上。
Once I found the points within the callback, I simply wrote the labels I wanted onto the canvas.
我添加的代码是：
var options = {
onAnimationProgress: function() { drawDatasetPointsLabels() },
onAnimationComplete: function() { drawDatasetPointsLabels() }
}
添加函数：
function drawDatasetPointsLabels() {
ctx.font = '.9rem "Gotham Book",sans-serif';
ctx.fillStyle = '#AAA';
ctx.textAlign="center";
$(Trends.datasets).each(function(idx,dataset){
$(dataset.points).each(function(pdx,pointinfo){
// First dataset is shifted off the scale line.
// Don't write to the canvas for the null placeholder.
if ( pointinfo.value !== null ) {
ctx.fillText(pointinfo.value,pointinfo.x,pointinfo.y - 15);
}
});
});
}
这里是整个代码源以及提供解决方案的新代码：
So here is the entire code source along with the new code providing the solution:
var data = {
labels: ["","Jun 2013","Jul 2013","Aug 2013","Sep 2013","Oct 2013","Nov 2013","Dec 2013","Jan 2014","Feb 2014","Mar 2014","Apr 2014","May 2014"],
datasets: [
{
label: "hemoglobin_1",
fillColor: "transparent",
strokeColor: "#65204c",
pointColor: "#65204c",
pointHighlightStroke: "#FFF",
data: [null,5.7,5.7,5.8,5.7,5.8,5.7,5.9,6.7,6.7,6.5,6.4,6.4]
},
{
label: "hemoglobin_2",
fillColor: "transparent",
strokeColor: "#ed7141",
pointColor: "#ed7141",
pointHighlightStroke: "#FFF",
data: [null,15.5,15.5,15.6,15.2,15.6,15.1,15.8,17,17.4,16.8,16.4,16.4]
},
{
label: "hemoglobin_3",
fillColor: "transparent",
strokeColor: "#de4760",
pointColor: "#de4760",
pointHighlightStroke: "#FFF",
data: [null,37.1,37,37.2,37.6,36.9,37.6,36.8,37.6,38,37.5,39.1,37.5]
},
{
label: "hemoglobin_4",
fillColor: "transparent",
strokeColor: "#fdcf7e",
pointColor: "#fdcf7e",
pointHighlightStroke: "#FFF",
data: [null,29.9,30.4,29.5,29.6,30.2,29.4,29.8,26.9,27,28.5,26.8,28.5]
},
{
label: "hemoglobin_5",
fillColor: "transparent",
strokeColor: "#a33a59",
pointColor: "#a33a59",
pointHighlightStroke: "#FFF",
data: [null,11.8,11.4,11.9,11.9,11.5,12.2,11.7,11.8,10.9,10.7,11.3,11.3]
}
]
};
var options = {
responsive: true,
scaleOverride: true,
scaleSteps: 10,
scaleStepWidth: 5,
scaleStartValue: 0,
showTooltips: false,
pointDot: true,
pointDotRadius : 6,
datasetStrokeWidth : 3,
bezierCurve : false,
scaleShowHorizontalLines: false,
scaleGridLineWidth : 2,
scaleGridLineColor : "#EEEEEE",
scaleLineWidth: 3,
scaleLineColor: "#000000",
scaleFontFamily: '"Gotham Book",sans-serif',
scaleFontSize: 18,
onAnimationProgress: function() { drawDatasetPointsLabels() },
onAnimationComplete: function() { drawDatasetPointsLabels() }
}
var ctx = $("#myChart").get(0).getContext("2d");
var Trends = new Chart(ctx).Line(data, options);
function drawDatasetPointsLabels() {
ctx.font = '.9rem "Gotham Book",sans-serif';
ctx.fillStyle = '#AAA';
ctx.textAlign="center";
$(Trends.datasets).each(function(idx,dataset){
// First dataset is shifted off the scale line.
// Don't write to the canvas for the null placeholder.
$(dataset.points).each(function(pdx,pointinfo){
if ( pointinfo.value !== null ) {
ctx.fillText(pointinfo.value,pointinfo.x,pointinfo.y - 15);
}
});
});
}
这是jsfiddle的原始版本： http://jsfiddle.net/s9eannLh
Here is the original problematic version on jsfiddle: http://jsfiddle.net/s9eannLh
[更新链接] / strong>
这里是jsfiddle的更新解决方案： https://jsfiddle.net/s9eannLh/ 82 /
感谢所有！
这篇关于如何用Chart.js显示折线图数据集点标签？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
