Angular 2 中的绑定的方法在无限循环吗？

<ion-card *ngFor="let item of inspects">

 <a [href]="nav(item)" target="_blank" ion-button icon-left clear small>
        <ion-icon name="pin"></ion-icon>
        <div>导航</div>
</a>

  nav(item) {
    let url = `bdapp://map/navi?location=${item.lng},${item.lat}`;
    if (Device.platform == 'iOS') {
      url = `baidumap://map/direction?origin=34.264642646862,108.95108518068&destination=${item.lng},${item.lat}&mode=driving&coord_type=wgs84&src=webapp.navi.yourCompanyName.yourAppName`;
    }
    console.log(url);
    return this.sanitizer.bypassSecurityTrustResourceUrl(url);
  }