无限滚动离子 2 错误

Question

我正在尝试在我的应用程序上实现无限滚动，但我收到错误 Property "then" does not exist on type "void" .当到达页面底部时，这将出现在我的文本编辑器和控制台中。这是从 http get 中提取的，它是

perpage:number = 50;
loadCategory1(start:number=0) {
  var url = "http://api.yummly.com/v1/api/recipes?_app_id=////&_app_key=////";
  if (this.Category1) {
    return Promise.resolve(this.Category1);
  }
  return new Promise(resolve => {
    this.http.get(url + "&allowedAllergy[]=396^Dairy-Free&allowedAllergy[]=393^Gluten-Free&maxResult=" + this.perpage + "&start=" + start)
      .map(res => res.json())
      .subscribe(data => {
        console.log(data);
        this.Category1 = data.matches;
        resolve(this.Category1);
      });
  });
}

相关代码是

export class Category1Page {
  public api: any;
  private start:number=0;
  constructor(public navCtrl: NavController, public navParams: NavParams, public apiAuthentication: ApiAuthentication) {
    this.loadRecipes();
  }
  loadRecipes(){
    this.apiAuthentication.loadCategory1(this.start)
    .then(data => {
      this.api = data;
    });
  } 
  doInfinite(infiniteScroll:any) {
     console.log('doInfinite, start is currently '+this.start);
     this.start+=50;
     this.loadRecipes().then(()=>{
       infiniteScroll.complete();
     });
  }
}

.HTML

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

任何指示都会很棒，谢谢。

Answer 1

属性"then"在类型"void"上不存在

您的loadRecipes方法没有返回任何内容(因此它是无效的(，并且您正在尝试调用then()...

this.loadRecipes().then(()=>{
       infiniteScroll.complete();
     });

尝试添加 return 关键字，如下所示：

loadRecipes(){
    return this.apiAuthentication.loadCategory1(this.start)
    .then(data => {
      this.api = data;
    });
  }