基于angular的菜单递归

基于angular的菜单递归

1. ngfor 顶层调用菜单组件

通过angular的for循环指令调用菜单树形数据结构。

          <app-menu-item
            *ngFor="let menuItem of menu"
            [menuItem]="menuItem"
            [isRoot]="true"
          ></app-menu-item>

2. 多级菜单的递归调用

菜单组件的ts文件,定义多级菜单默认都是闭合。

import { Component, OnInit, Input } from '@angular/core';
import { MenuItem } from '../models/menu-item';

@Component({
  selector: 'app-menu-item',
  templateUrl: './menu-item.component.html',
  styleUrls: ['./menu-item.component.scss']
})
export class MenuItemComponent implements OnInit {
  @Input() menuItem: MenuItem;
  @Input() isRoot: boolean;

  isOpen = false;

  constructor() {}

  ngOnInit() {}

  onMenuItemSelected(menuItem: MenuItem): void {
    console.log(menuItem);
  }
}
  • 定义多级菜单在有子菜单集合时为根菜单。定义菜单项的颜色,展开/闭合状态,点击事件(切换展开/闭合);
  • 根据菜单状态值判断是否进行下级菜单的渲染;
  • 定义当前菜单项为末级菜单时的模板;
<div>
  <p *ngIf="menuItem.children; else finalItem">
    <ion-button
      [color]="isRoot ? 'primary' : 'secondary'"
      [expand]="isRoot ? 'full' : 'block'"
      (click)="isOpen = !isOpen"
    >
      {{ menuItem.name }}
    </ion-button>

    <span *ngIf="isOpen">
      <app-menu-item
        *ngFor="let item of menuItem.children"
        [menuItem]="item"
      ></app-menu-item>
    </span>
  </p>
</div>

<ng-template #finalItem>
  <p>
    <ion-button color="light" expand="full" (click)="onMenuItemSelected(menuItem)">
      {{ menuItem.name }}
    </ion-button>
  </p>
</ng-template>

3. 菜单模型

  • 菜单名称,用于展示;
  • 菜单id,用于数据结构编排;
  • 子菜单集合,形成树形,便于展开;
export class MenuItem {
  name: string;
  id: number;
  children: Array<MenuItem>;
}

4.菜单的json文件

menu-Item.ts,与3中的菜单模型数据结构保持一致生成。

export const menuItems = [
  {
    name: 'Appetizers',
    id: 1,
    children: [
      {
        name: 'Fresco Salsa',
        id: 6,
        children: null
      }
    ]
  },
  {
    name: 'Main dishes',
    id: 2,
    children: [
      {
        name: 'Beef',
        id: 7,
        children: [
          {
            name: 'Crispy Orange Beef',
            id: 10,
            children: null
          }
        ]
      },
      {
        name: 'Burger',
        id: 8,
        children: [
          {
            name: 'Chorizo Burger',
            id: 11,
            children: null
          }
        ]
      },
      {
        name: 'Vegetarian',
        id: 9,
        children: [
          {
            name: 'Chile Rellenos',
            id: 12,
            children: null
          }
        ]
      }
    ]
  },
  {
    name: 'Side dishes',
    id: 3,
    children: [
      {
        name: 'Baked potato',
        id: 13,
        children: null
      }
    ]
  },
  {
    name: 'Salads',
    id: 4,
    children: [
      {
        name: 'Taco Slaw',
        id: 14,
        children: null
      }
    ]
  },
  {
    name: 'Desserts',
    id: 5,
    children: [
      {
        name: 'Crepes',
        id: 15,
        children: null
      }
    ]
  }
];

5 最终菜单效果图


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posted @ 2022-01-25 17:11  JerryMouseLi  阅读(400)  评论(0编辑  收藏  举报