ng2图表:在循环中添加标签可防止图表加载

使用模拟数据,一切都很好,但是当我尝试迭代父组件传递的数组时,图形本身不会显示,只有正交标记,控制台中不会显示任何内容。

这是我的代码:

import { Component, Input } from '@angular/core';
import { CHART_DIRECTIVES } from 'ng2-charts/ng2-charts';
import { Traffic } from './traffic';

@Component({
  selector: 'line-chart-component',
  directives: [CHART_DIRECTIVES],
  styles: [`
    .chart {
      display: block;
    }
  `],
  template: `
  <div style="display: block">
        <canvas baseChart
              [datasets]="datasets"
              [labels]="labels"
              [chartType]="'line'"
              (chartHover)="chartHovered($event)"
              (chartClick)="chartClicked($event)"></canvas>
        </div>
  `
})

export class LineChartComponent {
  _dataArray: Traffic[] = [];    
  private datasets = [
      {
        label: "Desktop",
        data: []
      }
    ];    
  private labels: string [] = [];

  @Input()
  set dataArray(dataArray: Traffic[]) {
    dataArray.forEach((data: any,index: number) => {
      this.datasets[0].data.push(Math.round(data.Value));
      this.labels.push(data.Date));
    });
    // this.labels = ['0','1','2','3','4','5','6','7','8','9','10','11'];
  }

  get dataArray() { return this._dataArray; }

  private options = {
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }]
    }
  };
}

N、 B:没有一个数组是未定义的。两者都有一个良好的结构,包含我的所有数据,并有适当的类型。而且 Data.date 返回一个字符串。

什么会导致这种行为?

谢谢