角度：* ng用於不顯示組件列表

Question

我是Angular / MEAN的新手。 我正在學習教程，那里沒有問題。 但是，現在我正在制作自己的應用程序，但它無法正確呈現-我無法弄清楚問題出在哪里。

所以我有一個模型+組件'ENTRY'。 我正在嘗試在我的應用程序中顯示2個測試條目（在AppComponent-constructor中創建+放入數組中），但未顯示。

// entry.model.ts

import { Segment } from '../segment/segment.model';
import { Marker } from '../marker/marker.model';

export class Entry {
    private _id: string;
    private _title: string;
    private _description: string;
    private _dateCreated: Date = new Date();
    private _dateLastModified;
    private _contents : string;

    constructor(title : string, description : string, contents : string){
        this._title = title;
        this._description = description;
        this._contents = contents;
    }

    public get title() : string {
        return this._title;
    }

    get description() : string {
        return this._description;
    }

    get contents() : string {
        return this._contents;
    }

}

// entry.component.ts

import { Component, OnInit, Input } from '@angular/core';
import { Entry } from './entry.model';

@Component({
  selector: 'app-entry',
  templateUrl: './entry.component.html',
  styleUrls: ['./entry.component.css']
})
export class EntryComponent implements OnInit {
  @Input() public entry: Entry;

  constructor() { }

  ngOnInit() {
  }

}

// entry.component.html

<p>
  This entry is called {{title}}.
  Its description is {{description}}.
  its contents are {{contents}}.
</p>

// app.component.ts

import { Component } from '@angular/core';
import { Entry } from './entry/entry.model';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  private _entries = new Array<Entry>();

  constructor() {
    const entry1 = new Entry("My Title",
    "This is an overly long description intended as an example, capiche?",
    "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.");
    this._entries.push(entry1);
    const entry2 = new Entry("My second title",
    "Some other description for testing purposes.",
    "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.");
    this._entries.push(entry2);
  }
}

// app.component.html

<!-- This one works, in that the html gets rendered but without any properties -->
<app-entry></app-entry>

<!-- All these other ones don't do anything -->
<div *ngFor='let currEntry of entries'>
  <app-entry></app-entry>
</div>
<app-entry *ngFor='let entry of entries'>
  {{entry}}
</app-entry>

<app-entry *ngFor='let currEntry of entries'
[entry]='currEntry'></app-entry>

<div>
  <ul>
    <li *ngFor='let currEntry of entries'>
      <app-entry [entry]='currEntry'></app-entry>
    </li>
  </ul>
</div>

有人知道我做錯了嗎？ 我將不勝感激任何幫助。

Answer 1

我想為了從視圖訪問條目輸入字段（屬性），您應該這樣做

<p *ngIf="entry" >
  This entry is called {{entry.title}}.
  Its description is {{entry.description}}.
  its contents are {{entry.contents}}.
</p>

您還需要在應用程序組件中將_entries更改為條目或其他方式（例如，用戶@ user184994指出）

編輯：添加了ngIf並且它可以工作