我使用的是angular 5.0.3,我想用一堆查询参数启动我的应用程序,比如/app?param1=hallo&param2=123。如何在Angular 2中从url中获取查询参数?对我没用。

有什么想法如何获得查询参数工作?

private getQueryParameter(key: string): string {
  const parameters = new URLSearchParams(window.location.search);
  return parameters.get(key);
}

这个私有函数帮助我获取参数,但我认为在新的Angular环境中这不是正确的方式。

(更新:) 我的主应用程序是这样的

@Component({...})
export class AppComponent implements OnInit {

  constructor(private route: ActivatedRoute) {}

  ngOnInit(): void {
    // would like to get query parameters here...
    // this.route...
  }
}

当前回答

import { ParamMap, Router, ActivatedRoute } from '@angular/router';

constructor(private route: ActivatedRoute) {}

ngOnInit() {
    console.log(this.route.snapshot.queryParamMap);
}

更新

import { Router, RouterStateSnapshot } from '@angular/router';

export class LoginComponent {
    constructor(private router: Router) {
        const snapshot: RouterStateSnapshot = router.routerState.snapshot;
        console.log(snapshot);  // <-- hope it helps
    }
}

其他回答

这对我很管用。我已经在路由模块中使用了子路由。


 this.route.firstChild.snapshot.paramMap.get('id');
   

这对我来说是最干净的解决方案

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';

export class MyComponent {
  constructor(
    private route: ActivatedRoute
  ) {}

  ngOnInit() {
    const firstParam: string = this.route.snapshot.queryParamMap.get('firstParamKey');
    const secondParam: string = this.route.snapshot.queryParamMap.get('secondParamKey');
  }
}
/*
Example below url with two param (type and name) 
URL : http://localhost:4200/updatePolicy?type=Medicare%20Insurance&name=FutrueInsurance
*/ 
  constructor(private route: ActivatedRoute) {
    //Read url query parameter `enter code here`
  this.route.queryParams.subscribe(params => {
    this.name= params['type'];
    this.type= params['name'];
    alert(this.type);
    alert(this.name);

 });

  }

父组件从ActivatedRoute获取空参数

对我有用:

import {Component, OnDestroy, OnInit} from '@angular/core';
import { Router, ActivatedRoute, Params, RoutesRecognized } from '@angular/router';

@Component({
  selector: 'app-navigation-bar',
  templateUrl: './navigation-bar.component.html',
  styleUrls: ['./navigation-bar.component.scss']
})
export class NavigationBarComponent implements OnInit, OnDestroy {
  private sub: any;
  constructor(private route: ActivatedRoute, private router: Router) {}

  ngOnInit() {
    this.sub = this.router.events.subscribe(val => {
      if (val instanceof RoutesRecognized) {
        console.log(val.state.root.firstChild.params);
      }
    });
  }

  ngOnDestroy() {
    this.sub.unsubscribe();
  }

}

不幸的是,最干净的解决方案并不是最可扩展的解决方案。在Angular的最新版本中,其他答案中建议你可以使用ActivatedRoute injectable,特别是使用snapshot属性,轻松获取查询参数:

this.route.snapshot.queryParamMap.get('param')

或者订阅属性(在查询字符串会更新的情况下使用,例如通过用户id导航):

this.route.queryParamMap.subscribe(params => console.log(params));

我在这里告诉你,这些解决方案有一个巨大的缺陷,一段时间没有得到解决:https://github.com/angular/angular/issues/12157

总而言之,唯一的防弹解决方案是使用优秀的老香草javascript。在本例中,我为URL操作创建了一个服务:

import { Injectable } from '@angular/core';
import { IUrl } from './iurl';

@Injectable()
export class UrlService {
    static parseQuery(url: string): IUrl {
        const query = url.slice(url.indexOf('?')+1).split('&').reduce( (acc,query) => {
            const parts = query.split('=');
            acc[parts[0]] = parts[1];
            return acc;
        }, {});

        return {
            a: query['a'],
            b: query['b'],
            c: query['c'],
            d: query['d'],
            e: query['e']
        }
    }
}