我想在 Angular 6 中切换菜单

Question

我想切换侧边导航栏 -

Taken a boolen value toggle_menu to true

and I am calling a function togg() on button click in the menu bar which sets the boolean value false anf hence div is toggled

但问题是 有 4 个按钮，每个按钮都有自己的 div 容器，每个按钮在点击时调用函数 togg()

这导致所有 div 同时打开。

但我想为每个按钮点击打开每个 div

代码：

import { Component, OnInit } from '@angular/core';
  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
  })
  export class AppComponent{
   toggle_menu: boolean = true;
    constructor() { }
    togg() {
      return this.toggle_menu = !this.toggle_menu;
      }
  }

html代码：

<button class="dropdown-btn" (click)="togg();"> Besics</button>
        <div *ngIf="!toggle_menu">
        <a routerLink="/imp-style"> Implimenting Style  </a>
        </div>

<button class="dropdown-btn" (click)="togg();">Image</button>
        <div *ngIf="!toggle_menu">

        <a routerLink="/slider"> Image Slider</a>
        </div>
<button class="dropdown-btn" (click)="togg();">Forms</button>
        <div *ngIf="!toggle_menu">
        <a routerLink="/signup"> Signup </a>
        <a routerLink="/signup"> Login </a>
        <a routerLink="/signup"> Register </a>
        </div>
<button class="dropdown-btn" (click)="togg();">Service</button>
        <div *ngIf="!toggle_menu">
        <a routerLink="/dipika-task"> Data Display </a>
        <a routerLink="/social-media"> Social Media </a>
        <a routerLink="/student"> Student </a>
        </div>

Answer 1

现在，您所有的 4 个按钮都有一个 div 内部，它取决于您的 .ts 代码中的相同布尔值。

如果您希望它们彼此独立切换并且每个按钮切换其自己的滑块，您需要在 .ts 代码中包含 4 个不同的布尔值。

这是一个例子：

<button class="dropdown-btn" (click)="togg();"> Besics</button>
    <div *ngIf="!toggle_menu1">
    <a routerLink="/imp-style"> Implimenting Style  </a>
    </div>
<button class="dropdown-btn" (click)="togg();">Image</button>
    <div *ngIf="!toggle_menu2">
    <a routerLink="/slider"> Image Slider</a>
    </div>
<button class="dropdown-btn" (click)="togg();">Forms</button>
    <div *ngIf="!toggle_menu3">
    <a routerLink="/signup"> Signup </a>
    <a routerLink="/signup"> Login </a>
    <a routerLink="/signup"> Register </a>
    </div>
<button class="dropdown-btn" (click)="togg();">Service</button>
    <div *ngIf="!toggle_menu4">
    <a routerLink="/dipika-task"> Data Display </a>
    <a routerLink="/social-media"> Social Media </a>
    <a routerLink="/student"> Student </a>
    </div>

Answer 2

export class AppComponent{
   dropdowns = {
    "besics": false,
    "images": false,
    "forms": false, 
    "service": false,
   }

    constructor() { }
    togg(string name) {
      dropwdowns[name] = !dropwdowns[name];
  }

并在您的 html 中使用 *ngIf

<button class="dropdown-btn" (click)="togg('besics');"> Besics</button>
        <div *ngIf="dropdowns['besics']">
        <a routerLink="/imp-style"> Implimenting Style  </a>
        </div>

<button class="dropdown-btn" (click)="togg('image');">Image</button>
        <div *ngIf="dropdowns['image']">
        <a routerLink="/slider"> Image Slider</a>
        </div>
<button class="dropdown-btn" (click)="togg('forms');">Forms</button>
        <div *ngIf="dropdowns['forms']">
        <a routerLink="/signup"> Signup </a>
             ....
        </div>
<button class="dropdown-btn" (click)="togg('service');">Service</button>
        <div *ngIf="dropdowns['service']">
        <a routerLink="/dipika-task"> Data Display </a>
             ....
</div>

Answer 3

您需要为每个按钮维护不同的标志才能使其正常工作..

<button class="dropdown-btn" (click)="Besicstogg();"> Besics</button>
        <div *ngIf="!Besicstoggle_menu">
        <a routerLink="/imp-style"> Implimenting Style  </a>
        </div>

<button class="dropdown-btn" (click)="Imagetogg();">Image</button>
        <div *ngIf="!Imagetoggle_menu">

        <a routerLink="/slider"> Image Slider</a>
        </div>
<button class="dropdown-btn" (click)="Formstogg();">Forms</button>
        <div *ngIf="!Formstoggle_menu">
        <a routerLink="/signup"> Signup </a>
        <a routerLink="/signup"> Login </a>
        <a routerLink="/signup"> Register </a>
        </div>
<button class="dropdown-btn" (click)="Servicetogg();">Service</button>
        <div *ngIf="!Servicetoggle_menu">
        <a routerLink="/dipika-task"> Data Display </a>
        <a routerLink="/social-media"> Social Media </a>
        <a routerLink="/student"> Student </a>
         </div>

并在 ts 文件中

 Servicetogg() {
      return this.Servicetoggle_menu = !this.Servicetoggle_menu;
  }
Besicstogg() {
      return this.Besicstoggle_menu = !this.Besicstoggle_menu;
  }
Imagetogg() {
      return this.Imagetoggle_menu = !this.Imagetoggle_menu;
  }
Formstogg() {
      return this.Formstoggle_menu = !this.Formstoggle_menu;
  }
Servicetogg() {
      return this.Servicetoggle_menu = !this.Servicetoggle_menu;
  }

Answer 4

你如何进一步简化它并摆脱冗余：

export interface MenuItem {
  title: string;
  links: { title: string, link: string }[]
}

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent{

   menuItems: MenuItem [] = [
     { 
       title: 'Basics' ,
       links: {
         title: 'Implementing Style',
         link: '/imp-style'
       }
     },
     // ... put the rest here
   ];

   activeMenu?: MenuItem;

   toggle(menu: MenuItem): void {
     this.activeMenu = this.activeMenu === menu ? void 0 : menu;
   }

   isActive(menu: MenuItem): boolean {
     return this.activeMenu === menu;
   }
}

模板

<ng-container *ngFor="let menu of menuItems">
  <button class="dropdown-btn" (click)="toggle(menu)">{{menu.title}}</button>
  <div *ngIf="isActive(menu)">
    <a *ngFor="let link of menu.links" [routerLink]="link.link">{{link.title}}</a>
  </div>
</ng-container>

如果您希望同时打开更多菜单：

activeMenus: MenuItem[] = [];

toggle(menu: MenuItem): void {
  if (this.isActive(menu)) {
    this.activeMenus.splice(this.activeMenus.indexOf(menu), 1);
  } else {
    this.activeMenu.push(menu);
  }
}

isActive(menu: MenuItem): boolean {
  return this.activeMenus.includes(menu);
}

Answer 5

您只需在 (click) 函数中传递菜单名称并存储在变量中即可。

<li class="list-group-item" (click)="toggleMenu('menu')"> 
    <a href="javascript:void(0)" >Menu</a>
</li>

并在控制器中使用以下代码：

toggleMenu(menu: string): void{
    if(this.toggle == true && this.subsetting!='' && this.subsetting!=menu)
    this.toggle = false;

    this.subsetting  = menu;
    this.toggle = !this.toggle;
}

但首先在class

中声明变量

toggle:boolean = false;
subsetting:string ='';

我想在 Angular 6 中切换菜单

I want to toggle menu in Angular 6

angular

angular-ui-router

angular-routing