ng2图表实时数据动画

Question

我用Angular 2和ng2-charts来做一个需要显示实时数据的仪表板。

目前，我的问题是当我更改与图表相关的数据时，图表会重新绘制所有数据点。由于这些数据将以每秒为单位输入，因此不适合我的目的。

我想做一个类似于这个演示的东西:http://www.highcharts.com/demo/dynamic-update，但是我没有highcharts的预算。

我的代码如下:

component.ts:

import { Component, OnInit } from '@angular/core';
import { Router } from '@angular/router';
import { CORE_DIRECTIVES, FORM_DIRECTIVES, NgClass } from '@angular/common';
import { CHART_DIRECTIVES } from 'ng2-charts';
@Component({
    selector: 'my-dashboard',
    templateUrl: 'app/dashboard.component.html',
    styleUrls: ['app/dashboard.component.css'],
    directives: [CHART_DIRECTIVES, NgClass, CORE_DIRECTIVES, FORM_DIRECTIVES]
})
export class DashboardComponent {
    // lineChart
    public lineChartData: Array<any> = [
        { data: [65, 59, 80, 81, 56, 55, 40], label: 'Series A' },
        { data: [28, 48, 40, 19, 86, 27, 90], label: 'Series B' },
        { data: [18, 48, 77, 9, 100, 27, 40], label: 'Series C' }
    ];
    public lineChartLabels: Array<any> = ['January', 'February', 'March', 'April', 'May', 'June', 'July'];
    public lineChartOptions: any = {
        responsiveAnimationDuration: 5000,
        animation: {},
        responsive: true
    };
    public lineChartColours: Array<any> = [
        { // grey
            backgroundColor: 'rgba(148,159,177,0.2)',
            borderColor: 'rgba(148,159,177,1)',
            pointBackgroundColor: 'rgba(148,159,177,1)',
            pointBorderColor: '#fff',
            pointHoverBackgroundColor: '#fff',
            pointHoverBorderColor: 'rgba(148,159,177,0.8)'
        },
        { // dark grey
            backgroundColor: 'rgba(77,83,96,0.2)',
            borderColor: 'rgba(77,83,96,1)',
            pointBackgroundColor: 'rgba(77,83,96,1)',
            pointBorderColor: '#fff',
            pointHoverBackgroundColor: '#fff',
            pointHoverBorderColor: 'rgba(77,83,96,1)'
        },
        { // grey
            backgroundColor: 'rgba(148,159,177,0.2)',
            borderColor: 'rgba(148,159,177,1)',
            pointBackgroundColor: 'rgba(148,159,177,1)',
            pointBorderColor: '#fff',
            pointHoverBackgroundColor: '#fff',
            pointHoverBorderColor: 'rgba(148,159,177,0.8)'
        }
    ];
    public lineChartLegend: boolean = true;
    public lineChartType: string = 'line';
    public randomize(): void {
        let _lineChartData: Array<any> = new Array(this.lineChartData.length);
        for (let i = 0; i < this.lineChartData.length; i++) {
            _lineChartData[i] = { data: new Array(this.lineChartData[i].data.length), label: this.lineChartData[i].label };
            for (let j = 0; j < this.lineChartData[i].data.length; j++) {
                _lineChartData[i].data[j] = Math.floor((Math.random() * 100) + 1);
            }
        }
        this.lineChartData = _lineChartData;
    }
    // events
    public chartClicked(e: any): void {
        console.log(e);
    }
    public chartHovered(e: any): void {
        console.log(e);
    }
}

component.html:

<div class="row">
    <div class="col-md-6">
        <base-chart class="chart"
                    [datasets]="lineChartData"
                    [labels]="lineChartLabels"
                    [options]="lineChartOptions"
                    [colors]="lineChartColours"
                    [legend]="lineChartLegend"
                    [chartType]="lineChartType"
                    (chartHover)="chartHovered($event)"
                    (chartClick)="chartClicked($event)"></base-chart>
    </div>
    <div class="col-md-6" style="margin-bottom: 10px;">
        <button class="btn btn-default" (click)="randomize()">Randomize Data</button>
    </div>
</div>

有没有人知道我如何使这个平滑动画作为数据的变化，而不是它重新绘制整个图形?

Answer 1

您可以尝试为新数据实现一个push方法，如下所示:

public pushOne(): void {
    this.lineChartData.forEach((x, i) => {
      const num = this.generateNumber(i);
      const data: number[] = x.data as number[];
      data.push(num);
    });
    this.lineChartLabels.push(`Label ${this.lineChartLabels.length}`);
  }

你也可以使用@ViewChild装饰器以编程方式控制图表的渲染(或不渲染)部分:

@ViewChild(BaseChartDirective, { static: true }) chart: BaseChartDirective;