类型'URLSearchParams'不可分配为键入'URLSearchParams'

Question

我想发送带有一些搜索参数的http.get请求到我的webapi以获取学生列表。我发现了如何做到这一点一些例子，但究竟做作为例子后，我得到这个奇怪的错误：

[ts] 
Type 'URLSearchParams' is not assignable to type 'URLSearchParams'. Two different types with this name exist, but they are unrelated. 
Property 'rawParams' is missing in type 'URLSearchParams'. 

这里是我的组件：

import { Injectable } from '@angular/core'; 
import { Http, Headers, Response, RequestOptions } from '@angular/http'; 
import 'rxjs/add/operator/map' 
import { User } from '../_models/user'; 

@Injectable() 
export class UserService { 

options = new RequestOptions({ 'headers': new Headers({ 'Content-Type': 'application/json' })}); 

constructor(private http: Http) { 
} 

createAccount(newUser: User){ 
return this.http.post('http://localhost:64792/api/students', JSON.stringify(newUser), this.options) 
.map((response: Response) => {    
    if(response.ok){ 
     console.log("Registration was a success"); 
     return true; 
    } else { 
     console.log("Registration failed"); 
     return false; 
     } 
}); 
} 

searchStudents(searchWords: Array<string>){ 
// Parameters obj- 
let params: URLSearchParams = new URLSearchParams(); 
for(let i = 0; i < searchWords.length; i++){ 
params.append('searchWords', searchWords[i]); 
} 
this.options.search = params; 
//Http request- 
} 
} 

什么导致这个错误？

Answer 1

看来本地URLSearchParams被宣布为你现在的代码，而new URLSearchParams();回报angular.io的URLSearchParams object

进口'rxjs/add/operator/map'，它应该工作。

import { URLSearchParams } from '@angular/http'; 

Answer 2

尝试使用set方法

searchStudents(searchWords: Array<string>){ 
// Parameters obj- 
let params: URLSearchParams = new URLSearchParams(); 
for(let i = 0; i < searchWords.length; i++){ 
params.set('searchWords', searchWords[i]); 
} 
this.options.search = params; 
//Http request- 
}