在创建折线图时，我遇到了图表 js 的问题。我想用指定的数据创建一个图表，并且在我将鼠标悬停在交点上时还需要有水平线和垂直线。我能够在悬停时创建垂直线，但找不到任何可以绘制两条线的解决方案。这是我在悬停时绘制垂直线的代码。
window.lineOnHover = function(){
Chart.defaults.LineWithLine = Chart.defaults.line;
Chart.controllers.LineWithLine = Chart.controllers.line.extend({
draw: function(ease) {
Chart.controllers.line.prototype.draw.call(this, ease);
if (this.chart.tooltip._active && this.chart.tooltip._active.length) {
var activePoint = this.chart.tooltip._active[0],
ctx = this.chart.ctx,
x = activePoint.tooltipPosition().x,
topY = this.chart.legend.bottom,
bottomY = this.chart.chartArea.bottom;
// draw line
ctx.save();
ctx.beginPath();
ctx.moveTo(x, topY);
ctx.lineTo(x, bottomY);
ctx.lineWidth = 1;
ctx.setLineDash([3,3]);
ctx.strokeStyle = '#FF4949';
ctx.stroke();
ctx.restore();
}
}
});
}
//create chart
var backhaul_wan_mos_chart = new Chart(backhaul_wan_mos_chart, {
type: 'LineWithLine',
data: {
labels: ['Aug 1', 'Aug 2', 'Aug 3', 'Aug 4', 'Aug 5', 'Aug 6', 'Aug 7', 'Aug 8'],
datasets: [{
label: 'Series 1',
data: [15, 16, 17, 18, 16, 18, 17, 14, 19, 16, 15, 15, 17],
pointRadius: 0,
fill: false,
borderDash: [3, 3],
borderColor: '#0F1731',
// backgroundColor: '#FF9CE9',
// pointBackgroundColor: ['#FB7BDF'],
borderWidth: 1
}],
// lineAtIndex: 2,
},
options: {
tooltips: {
intersect: false
},
legend: {
display: false
},
scales: {
xAxes: [{
gridLines: {
offsetGridLines: true
},
ticks: {
fontColor: '#878B98',
fontStyle: "600",
fontSize: 10,
fontFamily: "Poppins"
}
}],
yAxes: [{
display: true,
stacked: true,
ticks: {
min: 0,
max: 50,
stepSize: 10,
fontColor: '#878B98',
fontStyle: "500",
fontSize: 10,
fontFamily: "Poppins"
}
}]
},
responsive: true,
}
});
因此，当我将鼠标悬停在交叉点(绘制)上时，我希望将一条水平线与相同的垂直线放在一起。
请帮助我的家伙..提前谢谢。
最佳答案
您可以为从工具提示中获得的 y 坐标添加第二个绘图 block ，首先您移动到 chartArea 的左侧，您可以获得与底部和顶部相同的方式，然后在相同的位置向右移动是的
Chart.defaults.LineWithLine = Chart.defaults.line;
Chart.controllers.LineWithLine = Chart.controllers.line.extend({
draw: function(ease) {
Chart.controllers.line.prototype.draw.call(this, ease);
if (this.chart.tooltip._active && this.chart.tooltip._active.length) {
var activePoint = this.chart.tooltip._active[0],
ctx = this.chart.ctx,
x = activePoint.tooltipPosition().x,
y = activePoint.tooltipPosition().y,
topY = this.chart.legend.bottom,
bottomY = this.chart.chartArea.bottom,
left = this.chart.chartArea.left,
right = this.chart.chartArea.right;
// Set line opts
ctx.save();
ctx.lineWidth = 1;
ctx.setLineDash([3, 3]);
ctx.strokeStyle = '#FF4949';
// draw vertical line
ctx.beginPath();
ctx.moveTo(x, topY);
ctx.lineTo(x, bottomY);
ctx.stroke();
// Draw horizontal line
ctx.beginPath();
ctx.moveTo(left, y);
ctx.lineTo(right, y);
ctx.stroke();
ctx.restore();
}
}
});
var options = {
type: 'LineWithLine',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {
}
}
var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
</body>编辑:
您应该为此使用自定义插件，因为您每次移动光标时都不会绘制，您可以通过使用自定义插件来强制执行此操作:
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {
plugins: {
corsair: {
dash: [2, 2],
color: 'red',
width: 3
}
}
},
plugins: [{
id: 'corsair',
afterInit: (chart) => {
chart.corsair = {
x: 0,
y: 0
}
},
afterEvent: (chart, evt) => {
const {
chartArea: {
top,
bottom,
left,
right
}
} = chart;
const {
x,
y
} = evt;
if (x < left || x > right || y < top || y > bottom) {
chart.corsair = {
x,
y,
draw: false
}
chart.draw();
return;
}
chart.corsair = {
x,
y,
draw: true
}
chart.draw();
},
afterDatasetsDraw: (chart, _, opts) => {
const {
ctx,
chartArea: {
top,
bottom,
left,
right
}
} = chart;
const {
x,
y,
draw
} = chart.corsair;
if (!draw) {
return;
}
ctx.lineWidth = opts.width || 0;
ctx.setLineDash(opts.dash || []);
ctx.strokeStyle = opts.color || 'black'
ctx.save();
ctx.beginPath();
ctx.moveTo(x, bottom);
ctx.lineTo(x, top);
ctx.moveTo(left, y);
ctx.lineTo(right, y);
ctx.stroke();
ctx.restore();
}
}]
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
</body>编辑:
v3 的更新答案
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {
plugins: {
corsair: {
dash: [2, 2],
color: 'red',
width: 3
}
}
},
plugins: [{
id: 'corsair',
afterInit: (chart) => {
chart.corsair = {
x: 0,
y: 0
}
},
afterEvent: (chart, evt) => {
const {
chartArea: {
top,
bottom,
left,
right
}
} = chart;
const {
event: {
x,
y
}
} = evt;
if (x < left || x > right || y < top || y > bottom) {
chart.corsair = {
x,
y,
draw: false
}
chart.draw();
return;
}
chart.corsair = {
x,
y,
draw: true
}
chart.draw();
},
afterDatasetsDraw: (chart, _, opts) => {
const {
ctx,
chartArea: {
top,
bottom,
left,
right
}
} = chart;
const {
x,
y,
draw
} = chart.corsair;
if (!draw) {
return;
}
ctx.lineWidth = opts.width || 0;
ctx.setLineDash(opts.dash || []);
ctx.strokeStyle = opts.color || 'black'
ctx.save();
ctx.beginPath();
ctx.moveTo(x, bottom);
ctx.lineTo(x, top);
ctx.moveTo(left, y);
ctx.lineTo(right, y);
ctx.stroke();
ctx.restore();
}
}]
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.8.0/chart.js"></script>
</body>关于javascript - 在图表js中鼠标悬停绘制水平和垂直线，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/70112637/