javascript - ionic 2无限滚动错误

Question

我正在尝试在 ionic2 中进行无限滚动，但是每当页面加载时我都会收到此错误 Cannot read property 'complete' of undefined

HTML

<ion-content>

 <ion-list>
   <ion-item *ngFor="let item of posts" (click)="passurl($event,item)">
     <h2>{{item.title}}</h2>
     </ion-item>
 </ion-list>

 <ion-infinite-scroll (ionInfinite)="ionViewDidLoad($event)">
   <ion-infinite-scroll-content></ion-infinite-scroll-content>
 </ion-infinite-scroll>

</ion-content>

JS

ionViewDidLoad(infiniteScroll){
    let loader = this.LoadingController.create({
    content: 'Please Wait'
    });
    loader.present().then(()=>{
      this.http.get('http://mynewweb/templates/messages/titles.php?church_id='+ this.church_id+'&msg_type='+this.NavParams.data.id+ "&page="+this.page).map(res => res.json()).subscribe(data =>{
            console.log(JSON.stringify(data));
            setTimeout(() => {
            for(var i=0;i<data.length;i++){
              this.numofposts = data.length;
            this.posts.push(data[i]);
             }
        infiniteScroll.complete();
          }, 500);
        });
     this.page=this.page+1;
    loader.dismiss();
    });

  }

我遵循了他们网站上关于 ionic2 框架的文档。有什么帮助吗？谢谢

Answer 1

您不能使用 ionViewDidLoad Hook 作为 InfiniteScroll 的目标.您可以将相同的逻辑放在不同的方法中，如下所示:

<ion-infinite-scroll *ngIf="!hideInfinite" (ionInfinite)="loadData($event)">
  <ion-infinite-scroll-content></ion-infinite-scroll-content>
</ion-infinite-scroll>

在组件代码中:

public hideInfinite: boolean;

public loadData(infiniteScroll?: any): void {
    let loader = this.LoadingController.create({
        content: 'Please Wait'
    });

    loader.present().then(()=>{

        this.http.get('http://mynewweb/templates/messages/titles.php?church_id='+ this.church_id+'&msg_type='+this.NavParams.data.id+ "&page="+this.page).map(res => res.json()).subscribe(
            data => {
                console.log(JSON.stringify(data));

                if(!data || !data[0]) {
                    // Hide the infiniteScroll if there's no more data
                    this.hideInfinite = true;
                }

                setTimeout(() => {
                    for(var i=0;i<data.length;i++) {
                        this.numofposts = data.length;
                        this.posts.push(data[i]);
                    }

                    // Check if it's not null/undefined before calling the complete method
                    if(infiniteScroll) {
                        infiniteScroll.complete();
                    }

                }, 500);
            });

        this.page=this.page+1;
        loader.dismiss();
    });

}

如果你想在 ionViewDidLoad 生命周期 Hook 中使用相同的逻辑，你可以调用相同的方法:

ionViewDidLoad(){
  // You can now call the method without sending anything, 
  // since in the code we check if the infiniteScroll is defined 
  // before using its methods
  this.loadData();
}