时间：2022-10-01 13:35:39 | 栏目：AngularJS | 点击：次
项目中遇到一个问题，就是在ngInit()中调用方法，只调用一次的问题，当父组件传值变化时，并不会再次执行。
import {
Component,
Input,
OnChanges,
SimpleChanges
} from '@angular/core';
import {
NavController
} from 'ionic-angular';
@Component({
selector: 'cs-img-lazy',
templateUrl: 'cs-img-lazy.html'
})
export class CsImgLazyComponent implements OnChanges {
@Input() default: string;
@Input() src: string
constructor(public navCtrl: NavController) {
}
ngOnInit() {
}
ngOnChanges(changes: SimpleChanges) {
console.log('ngOnChanges', this.src);
this.loadImage(this.src, () => {
this.default = this.src;
});
}
loadImage(url, callback) {
var img = new Image();
img.onload = () => {
if (img.complete) {
img.onload = null
callback(img);
return;
}
}
img.src = url;
}
}