我想隐藏一些没有有用值（“0”）的条形，但我不知道该怎么做，因为我不能使用任何 Chart.Js 插件，也不能只是隐藏整个数据集，因为我正在使用 SQL 表将值“放入”Chart.Js。
{{3}}
注意：我只想隐藏 Value 而不是整个栏本身。
//coloring the bars from light blue (receiverColor) to dark blue (performancePayColor)
var receiverColor = "#7ec0ee";
var timeWageColor = "#368DD6";
var performancePayColor = "#214B7D";
//removing of chart when openening a new OE
// var chartContainer = document.getElementById('chartContainer');
// chartContainer.innerHTML = "";
for (var x = 0; x < charts.length; x++) {
var chartData = charts[x];
var sumChartValues = [];
//adding up the Arrays
for (var i = 0; i < chartData.GE.length; i++) {
sumChartValues.push(chartData.GE[i] + chartData.LL[i] + chartData.ZL[i]);
}
//creating a TempChart canvas with same values as chart1 to be able to delete Chart1 canvas
var chart = document.createElement("canvas");
chart.id = "Chart" + x;
//make the Charts responsive
var width = $(window).width();
var paddingL; //= 0;
var paddingR; //= 0;
if (width >= 2560) {
// chart.height = height / 2.2;
chart.width = width / 2.2;
paddingL = 25;
paddingR = 25;
}
else if (width >= 1440) {
// chart.height = height / 2.2;
chart.width = width / 2.2;
paddingL = 25;
paddingR = 25;
}
else if (width >= 1024) {
// chart.height = height / 2.2;
chart.width = width / 2.5;
paddingL = 20;
paddingR = 20;
}
else if (width >= 768) {
// chart.height = height / 2;
chart.width = width / 1.25;
paddingL = 30;
paddingR = 30;
}
else {
//chart.height = height;
chart.width = width / 1.25;
}
document.getElementById("chartContainer").appendChild(chart);
//var originalOnClick = Chart.defaults.global.legend.onClick;
new Chart("Chart" + x, {
//barchart is what we use normally, change type if something else is needed.
type: "bar",
data: {
//labels is for the Values of the first x-Axis (we normally use KW)
labels: chartData.KW,
//datasets are the Bars that are displayed on the charts (each Dataset is one different Bar part a.e. a different color and value on one bar and KW)
datasets: [
{
label: "Leistungslohn",
backgroundColor: performancePayColor,
data: chartData.LL,
xAxesID: "lowerXAxis",
},
{
label: "Zeitlohn",
backgroundColor: timeWageColor,
data: chartData.ZL,
xAxesID: "lowerXAxis"
},
{
label: "Gehaltsempfänger",
backgroundColor: receiverColor,
data: chartData.GE,
xAxesID: "lowerXAxis"
}]
},
options: {
//Set the Chart responsive
maintainAspectRatio: true,
responsive: false,
layout: {
padding: {
left: paddingL,
right: paddingR
}
},
//Dynamic Chart title display on top of the Legend
title: {
size: '200',
display: true,
text: chartData.O_Long[0] + ' (' + chartData.O_Short[0] + ')',
},
//Enables legend Over the bars (Leistungslohn, Zeitlohn and Gehaltsempfänger)
legend: {
display: true,
position: 'bottom'
},
//Enables tooltips when hovering over bars
tooltips: {
enabled: true
},
hover: {
//disables number flickering when moving mouse across bars
animationDuration: 0,
//disables hover effect (change of bar color when hovering over a bar)
mode: null
},
animation: {
//duration = build up time for the chart in ms, 0 = no visible animation.
duration: 0,
onComplete: function () {
//Shows bar values on top of each bar and Formats them
var ctx = this.chart.ctx;
var legendItems = this.chart.legend.legendItems;
var max = this.chart.scales['y-axis-0'].max;
ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontSize, 'bold', Chart.defaults.global.defaultFontFamily);
//coloring the values white
ctx.fillStyle = this.chart.config.options.defaultFontColor = "#FFF";
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
//Calculation of the required scale
var chartHeight = this.height;
this.data.datasets.forEach(function (dataset) {
var index = -1;
for (var i = 0; i < legendItems.length; i++) {
if (legendItems[i].text == dataset.label && !legendItems[i].hidden) {
index = i;
break;
}
}
if (index != -1) {
for (var i = 0; i < dataset.data.length; i++) {
var model = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._model;
ctx.fillText(dataset.data[i], model.x, model.y + (dataset.data[i] / max * ((chartHeight / 2) - 50)));
}
}
})
//hide zero values
},
},
scales: {
xAxes: [{
//Stacks mutliple Datasets on top of each other
ID: "lowerXAxis",
stacked: true,
gridLines: {
//removes x-Axes grid lines
display: false
}
},
//Second x-Axes:
{
ID: "upperXAxis",
position: "top",
offset: true,
gridLines: {
//removes x-Axes grid lines
display: false
}
}],
yAxes: [{
//Stacks mutliple Datasets on top of each other
stacked: true,
scaleLabel: {
offset: true,
display: true,
labelString: 'Anzahl Personen',
},
ticks: {
//Makes the chart start at 0 to prevent negative values and to prevent formatting errors
beginAtZero: true,
}
}]
}
}
});
}
}```
答案 0 :(得分：0)
在 options.animation.onComplete 回调函数中，您使用 ctx.fillText(...) 绘制文本。如果值为零，请不要绘制文本。
为此，您应该添加一个 if 语句，如下所示：
if (dataset.data[i] > 0) {
ctx.fillText(dataset.data[i], model.x, model.y + (dataset.data[i] / max * ((chartHeight / 2) - 50)));
}
如果您的问题建议将值定义为字符串，则可能需要稍微更改 if 语句（即 if (dataset.data[i] != '0') {）。