無法解決所有參數的HttpParams：（？）

Question

所以，當我做到這一點

import { Injectable } from '@angular/core'; 
import { Http, Response } from '@angular/http'; 
import { HttpParams } from '@angular/common/http'; 
import { Observable } from 'rxjs/Observable'; 
import { EnvironmentConfig } from '../../../common/shared/environment-config/environment-config.service'; 

@Injectable() 
export class AccessRequestService { 
    private url: string; 

    constructor(
    private http: Http, 
    private config: EnvironmentConfig 
) { 
    this.url = this.config['api']; 
    } 

    getRequests(start: string, end: string): Observable<any> { 
    const params = new HttpParams(); 
    params.set('start', start); 
    params.set('end', end); 

    return this.http.get(`${this.url}/objects`, { params }) 
     .timeout(12000) 
     .map((res: Response) => res.json().objects); 
    } 
} 

我得到一個錯誤

main.ssi.ts:10 Uncaught Error: Can't resolve all parameters for HttpParams: (?). 
    at syntaxError (http://ssi.local:4200/vendor.bundle.js:27181:34) 
    at CompileMetadataResolver.webpackJsonp.../../../compiler/@angular/compiler.es5.js.CompileMetadataResolver._getDependenciesMetadata (http://ssi.local:4200/vendor.bundle.js:41256:35) 
    at CompileMetadataResolver.webpackJsonp.../../../compiler/@angular/compiler.es5.js.CompileMetadataResolver._getTypeMetadata (http://ssi.local:4200/vendor.bundle.js:41124:26) 
    at CompileMetadataResolver.webpackJsonp.../../../compiler/@angular/compiler.es5.js.CompileMetadataResolver._getInjectableMetadata (http://ssi.local:4200/vendor.bundle.js:41110:21) 
    at CompileMetadataResolver.webpackJsonp.../../../compiler/@angular/compiler.es5.js.CompileMetadataResolver.getProviderMetadata (http://ssi.local:4200/vendor.bundle.js:41401:40) 
    at http://ssi.local:4200/vendor.bundle.js:41330:49 
    at Array.forEach (native) 
    at 

，我已經在模塊中提供的HttpParams

Answer 1

你好，你可以嘗試這個職位

Http params in Angular 4.3

，如果你想知道更多

參考的文檔http headers