Angular 2 — 浏览网页而不重新加载那些页面通用的组件 [英] Angular 2 — navigate through web pages without reloading a component that is common for those pages

问题描述

您可以在此处找到示例应用:http://ivan-khludov.com/

这是我的根组件:

import { Component } from '@angular/core';@成分({选择器:'根'，模板:`<h1>我的虚拟 Angular 应用程序</h1><路由器插座></路由器插座><导航><a routerLink="/section-1/1" routerLinkActive="active">第 1 部分 - 第 1 页</a><span>||</span><a routerLink="/section-1/2" routerLinkActive="active">Section 1 - Page 2</a><span>||</span><a routerLink="/section-2/1" routerLinkActive="active">Section 2 - Page 1</a><span>||</span><a routerLink="/section-2/2" routerLinkActive="active">Section 2 - Page 2</a></nav>`})导出类 AppWrapper {}

第 1 部分第 1 页的组件:

import { Component } from '@angular/core';@成分({选择器:'secapagea'，模板:`<h2>第 1 部分 - 第 1 页</h2><countera></countera>`})导出类 Section1Page1 {}

第 1 部分第 2 页几乎相同:

import { Component } from '@angular/core';@成分({选择器:'secapageb'，模板:`<h2>第 1 部分 - 第 2 页</h2><countera></countera>`})导出类 Section1Page2 {}

一个计数器组件:

import { Component } from '@angular/core';@成分({选择器:'countera'，模板:`<div>经过的秒数:{{this.count}}</div>`})导出类 Section1Counter {计数:数量；构造函数(){this.count = 0;setInterval(() => {this.count++;}, 1000);}}

把我打开的部分的第一页的情况.有没有办法在不重新加载计数器的情况下导航到同一部分的第二页?我想为此类导航问题找到一个通用的解决方案 - 它可能不是计数器组件，而是侧边栏导航或部分标题或其他内容.

解决方案

是的，完全可以编写一个可以处理多个 Routes 的 Component，而无需每次都重新构建 Component.

如果您创建一个组件来处理所有页面，如定义的以下路由:

const 路由:路由 = [{ 路径:'section-1/:page'，组件:Section1PageX }];

您可以订阅路由参数页面"并处理组件内的页面更改.这可以防止 Angular2 每次都重新构建页面组件.

@Component({选择器:'secapagea'，模板:`<h2>第 1 部分 - 第 {{page}} 页</h2><countera></countera>`})导出 Section1PageX {私人页面:字符串；构造函数(私有路由:ActivatedRoute){}ngOnInit() {this.sub = this.route.params.subscribe(params => {this.page = params['page'];//处理页面变化});}ngOnDestroy() {//当您离开该部分时取消订阅this.sub.unsubscribe();}}

所以你的 Section1Counter 组件只有在你离开整个部分时才会被销毁.

您还可以在我们的博客文章 Angular 中阅读更多相关信息2 示例

Here you can find an example app: http://ivan-khludov.com/

This is my root component:

import { Component } from '@angular/core';

@Component({
  selector: 'root',
  template: `
  <h1>My Dummy Angular App</h1>
  <router-outlet></router-outlet>
  <nav>
    <a routerLink="/section-1/1" routerLinkActive="active">Section 1 - Page 1</a>
    <span>||</span>
    <a routerLink="/section-1/2" routerLinkActive="active">Section 1 - Page 2</a>
    <span>||</span>
    <a routerLink="/section-2/1" routerLinkActive="active">Section 2 - Page 1</a>
    <span>||</span>
    <a routerLink="/section-2/2" routerLinkActive="active">Section 2 - Page 2</a>
  </nav>
  `
})

export class AppWrapper {

}

A component for section 1, page 1:

import { Component } from '@angular/core';

@Component({
  selector: 'secapagea',
  template: `
  <h2>Section 1 - Page 1</h2>
  <countera></countera>
  `
})

export class Section1Page1 {

}

Almost the same thing for section 1, page 2:

import { Component } from '@angular/core';

@Component({
  selector: 'secapageb',
  template: `
  <h2>Section 1 - Page 2</h2>
  <countera></countera>
  `
})

export class Section1Page2 {

}

A counter component:

import { Component } from '@angular/core';

@Component({
  selector: 'countera',
  template: `
  <div>Seconds elapsed: {{this.count}}</div>
  `
})

export class Section1Counter {

    count: number;

    constructor() {

        this.count = 0;

        setInterval(() => {

            this.count ++;

        }, 1000);

    }

}

Put the case that I opened the first page of the section. Is there a way to navigate to the second page of the same section without reloading the counter? I want to find a general solution for such navigation issues — it could be not a counter component but sidebar navigation or section heading or something else.

解决方案

Yeah it is absolutely possible to write a Component which can handle multiple Routes without reconstructing the Component each time.

If you create a component which handles all pages together as defined with the following route:

const routes: Routes = [
  { path: 'section-1/:page', component: Section1PageX }
];

You can subscribe on the route parameter "page" and handle the page change within your Component. This prevents Angular2 from reconstructing the page Component each time.

@Component({
  selector: 'secapagea',
  template: `
  <h2>Section 1 - Page {{page}}</h2>
  <countera></countera>
  `
})
export Section1PageX {
  private page: string;

  constructor(private route: ActivatedRoute) {}

  ngOnInit() {
    this.sub = this.route.params.subscribe(params => {
       this.page = params['page'];
       //handle the page change
    });  
  }

  ngOnDestroy() {
    //unsubscribe when you leave the section
    this.sub.unsubscribe();
  }
}

So your Section1Counter Component will only be destroyed if you leave the entire section.

You can also read more about this in our Blog Post Angular 2 by Example

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