角度2 bootstrap旋转木马作为背景

Question

尝试做旋转木马并把图片作为背景，希望有人可以帮助我，抱歉我的英文破碎:) 这里我键入的代码： 第一个角度：

import { Component, OnInit } from '@angular/core';
import { NgStyle } from '@angular/common';
import { NgFor } from '@angular/common';

@Component({
  selector: 'app-slider',
  templateUrl: './slider.component.html',
  styleUrls: ['./slider.component.css']
})
export class SliderComponent implements OnInit {

  constructor() { }

  images = [];

  ngOnInit() {
    this.images = [
  {"id":1, "url":"assets/img/header.jpeg"},
  {"id":2, "url":"assets/img/velo2.jpeg"},
  {"id":3, "url":"assets/img/velo3.jpeg"},
    ]
  }
}

和我的HTML代码：

<carousel >
  <slide *ngFor = "let image of images" >
    <div [ngStyle]="{'background-image': url(' + image.url + ')}"></div>
  </slide>

</carousel>

这是我的错误：

ERROR TypeError: _co.url is not a function
at Object.eval [as updateDirectives] (ng:///AppModule/SliderComponent.ngfactory.js:17)
at Object.debugUpdateDirectives [as updateDirectives] (vendor.bundle.js:82907)
at checkAndUpdateView (vendor.bundle.js:82087)
at callViewAction (vendor.bundle.js:82452)
at execEmbeddedViewsAction (vendor.bundle.js:82410)
at checkAndUpdateView (vendor.bundle.js:82088)
at callViewAction (vendor.bundle.js:82452)
at execComponentViewsAction (vendor.bundle.js:82384)
at checkAndUpdateView (vendor.bundle.js:82093)
at callViewAction (vendor.bundle.js:82452)