angular - 如何在 Angular 中为 *ngFor 设置动画？

Question

我需要在填充和显示 ngFor 列表时对其进行动画处理。每个元素都应该有一个过渡，比方说 something like this .

我该怎么做？

Answer 1

它有一些问题，因为 ngFor 做了一些多余的添加/删除，导致项目被动画化，这不应该:

import {Component} from 'angular2/core';
import { Component, Directive, OnDestroy, Input } from 'angular2/core';

@Component({
    selector: 'my-app',
    template: `<div (click)="$event.preventDefault()">
        <button type="button" (click)="pushItem()">Push</button>
        <button type="button" (click)="removeItemLast()">Remove Last</button><br/>
        <button type="button" (click)="unshiftItem()">Unshift</button>
        <button type="button" (click)="removeItemFirst()">Remove First</button><br/>
        <ul>
          <li class="my-animation" *ngFor="#item of items">
            {{item.title}}
          </li>
        </ul>
      </div>`
})
export class AppComponent {
  private count:number = 1;
  public items: Array<any>;
  constructor() { 
    console.clear(); 
    this.items = [];
    this.items.push(this.newItem());
    this.items.push(this.newItem());
    }
    pushItem() {
        this.items.push(this.newItem());
    },
    removeItemLast() {
      if(this.items.length > 0) this.items.splice(this.items.length - 1, 1);
    },
    unshiftItem() {
        this.items.unshift(this.newItem());
    },
    removeItemFirst() {
      if(this.items.length > 0) this.items.splice(0, 1);
    },
    newItem() {
      return {title: 'Item' + this.count++};
    }

}

@keyframes MyAnimation {
  0% {
    padding-left: 100px;
  }
  100% {
    padding-left: 0px;
  } 
}

.my-animation {
  animation: MyAnimation 1s;
}

Plunker example (RC.x) 来自 https://github.com/angular/angular/issues/7239演示了这个问题。

更新

这个问题很久以前就解决了

工作 Demo on stackblitz