ngx-charts折线图，如何始终显示带点的折线图作为数据点 [英] ngx-charts line chart, how to show the line chart with dot for the data point all the time

问题描述

对于ngx-charts折线图，它显示折线图，但数据点没有点.

如果将鼠标悬停在数据点上，它会在数据点上显示一个点，并带有标签工具提示.

我喜欢这样的折线图，以便始终用点显示所有数据点.

在ngx-charts折线图的数据点上如何显示点时，我需要您的帮助

以下是ngx-chart的示例

定制服务在划线图上绘制点:

 从'@ angular/core'导入{可注入}；@Injectable()导出类CustomLinerChartService {/***自定义:覆盖SVG以使点始终显示在划线图上*由于ngx图表已不再支持*/showDots(图表){令index = 0;const路径= chart.chartElement.nativeElement.getElementsByClassName(线系列");const color = chart.chartElement.nativeElement.getElementsByClassName(线高亮");对于(让路径的路径){const chrtColor = color [index] .getAttribute('ng-reflect-fill');const pathElement = path.getElementsByTagName('path')[0];const pathAttributes = {'marker-start':`url(#dot $ {index})`，'marker-mid':`url(#dot $ {index})`，'marker-end':`url(#dot $ {index})`};this.createMarker(chart，chrtColor，index);this.setAttributes(pathElement，pathAttributes);索引+ = 1;}}/***创建标记**/createMarker(图表，颜色，索引){const svg = chart.chartElement.nativeElement.getElementsByTagName('svg');var marker = document.createElementNS('http://www.w3.org/2000/svg'，标记");var circle = document.createElementNS('http://www.w3.org/2000/svg'，'圆圈');svg [0] .getElementsByTagName('defs')[0] .append(marker);marker.append(circle);const m = svg [0] .getElementsByTagName('marker')[0];const c = svg [0] .getElementsByTagName('circle')[0];const markerAttributes = {id:`dot $ {index}`，viewBox:'0 0 10 10'，refX:5引用:5，markerWidth:5markerHeight:5};const circleAttributes = {cx:5cy:5r:5填色};m.append(圆圈);this.setAttributes(m，markerAttributes);this.setAttributes(c，circleAttributes);}/***设置多个属性*/setAttributes(element，attributes){对于(属性中的const键){element.setAttribute(key，attributes [key]);}}} 

，然后在视图初始化之后将数据设置为图表调用:

  @ViewChild('chart')图表:任意；ngAfterViewInit(){this.customLinerChartService.showDots(this.chart);} 

确保图表上有参考文献:

 < ngx-charts-line-chart#chart> 

更新

您不能依赖 ng-reflect-fill 类，因为它只是增加了开发的气氛，因此可以提供您的颜色作为数组并基于索引进行选择

for ngx-charts line chart, it show the line chart, but there is no dot for the data point.

If you hover the data point, it show a dot for the data pint and also with a label tooltip.

I like to have the line chart to show all the data point with a dot all the time like this.

I need your help on how to show a dot at the data point in ngx-charts line chart

Here is the sample for ngx-chart https://github.com/kedmenecr/cinnamon-angular5-with-ngx-charts

Here is the source code for ngx-chart libary . https://github.com/swimlane/ngx-charts

thanks.

解决方案

if anyone still needs this feature I workaround this feature with a non-super clean solution but it works with no side effect so far :

custom service to draw the points over liner chart:

import { Injectable } from '@angular/core';
@Injectable()
export class CustomLinerChartService {
    /**
     * custom: override SVG to have the dots display all the time over the liner chart
     * since it's not supported anymore from ngx chart
     */

    showDots(chart) {
        let index = 0;
        const paths = chart.chartElement.nativeElement.getElementsByClassName(
            'line-series'
        );
        const color = chart.chartElement.nativeElement.getElementsByClassName(
            'line-highlight'
        );

        for (let path of paths) {
            const chrtColor = color[index].getAttribute('ng-reflect-fill');
            const pathElement = path.getElementsByTagName('path')[0];
            const pathAttributes = {
                'marker-start': `url(#dot${index})`,
                'marker-mid': `url(#dot${index})`,
                'marker-end': `url(#dot${index})`
            };
            this.createMarker(chart, chrtColor, index);
            this.setAttributes(pathElement, pathAttributes);
            index += 1;
        }
    }

    /**
     * create marker
     *
     */

    createMarker(chart, color, index) {
        const svg = chart.chartElement.nativeElement.getElementsByTagName('svg');
        var marker = document.createElementNS(
            'http://www.w3.org/2000/svg',
            'marker'
        );
        var circle = document.createElementNS(
            'http://www.w3.org/2000/svg',
            'circle'
        );
        svg[0].getElementsByTagName('defs')[0].append(marker);
        marker.append(circle);
        const m = svg[0].getElementsByTagName('marker')[0];
        const c = svg[0].getElementsByTagName('circle')[0];

        const markerAttributes = {
            id: `dot${index}`,
            viewBox: '0 0 10 10',
            refX: 5,
            refY: 5,
            markerWidth: 5,
            markerHeight: 5
        };

        const circleAttributes = {
            cx: 5,
            cy: 5,
            r: 5,
            fill: color
        };
        m.append(circle);

        this.setAttributes(m, markerAttributes);
        this.setAttributes(c, circleAttributes);
    }

    /**
     * set multiple attributes
     */
    setAttributes(element, attributes) {
        for (const key in attributes) {
            element.setAttribute(key, attributes[key]);
        }
    }
}

and after your view init and the data is set to the chart call :

@ViewChild('chart') chart: any;

ngAfterViewInit() {
    this.customLinerChartService.showDots(this.chart);
}

make sure to have the reference on your chart :

<ngx-charts-line-chart #chart>

UPDATE

you can't rely on ng-reflect-fill class since it just added in development mood so insted provide your colors as array and chose it based on index for example

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