Question

我正在尝试通过异步管道加载ngfor中的服务数据，但我遇到了一个问题：这是我的组成部分：

    <app-book-list *ngFor="let app of apps | async | serachBox:searchBooksByName | filterSearch:showTechBooks:showMgmBooks:showFictionBooks " 
  [bookdetails]="app"></app-book-list>

在这个组件中，应用程序应该来自服务。

在我的component.ts文件中：

     public apps= [];
  ngOnInit() {
    this.ServerService.getBookDetails()
      .then((data)=>{
        this.apps = data;
      })
  }

以下是承诺：

getBookDetails（）{

let promise = new Promise((resolve,reject)=>{
   return this.http.get('https://lib-http-ng.firebaseio.com/bookdetails.json')
        .toPromise()
        .then((res)=>{
            const data = Object.values(res.json());
            resolve(data[0])
        })

})
return promise;

} 我收到与异步管道相关的错误。

1

  Type '{}' is not assignable to type 'Promise<any>'.

Answer 1

Dropit()
{
    setLayout(null);
    tf = new JTextField();
    tf.setBounds(50, 50, 100, 100);
    add(tf);
    map.put("mon", mon);
    map.put("tue", tue);
    lis = new JComboBox<String>(days);
    lis.setSelectedItem("sat");
    lis.addActionListener(this);
    lis.setBounds(100,100,100,100);
    add(lis);


    pop = new JComboBox<String>();
    pop.setBounds(200,100 , 100, 100);
    pop.setVisible(false);
    add(pop);
    setVisible(true);
    setSize(500,500);
}

public void actionPerformed(ActionEvent e)
{
    lis = (JComboBox<String>) e.getSource();
    String name = (String) lis.getSelectedItem();
    tf.setText(name);

    if (map.containsKey(name))
    {
        pop.removeAllItems();
        for (String s: map.get(name))
            pop.addItem(s);
        pop.setVisible(true);
    } else 
        pop.setVisible(false);
}

应该是

this.ServerService.getBookDetails()
  .then((data)=>{
    console.log(data);
    this.apps =  data;
  })

或删除this.apps = this.ServerService.getBookDetails()

InvalidPipeArgument：'[object Object]，[object Object]，[object Object]，[object Object]，[object Object]，[object Object]，

1 个答案: