将URLSearchParams转换为HttpParams-Angular HttpClient

编程问答 2022-06-10

问题描述

我正在尝试从Angular8上的service.ts将Http更新为HttpClient。

我更改了HttpClient和HttpHeaders的Http和Headers，并删除了'.pipe（map（（response）=> response.json（）。response））;'。选项search：params.toString（）在HttpParams上不起作用，并且按照建议，我仅更改为params。

但是请求无法正常运行：（

在（Http）之前

import { Injectable,OnDestroy } from '@angular/core';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Http,Headers,Jsonp } from '@angular/http';
import { Environment } from '../app.component';
//my components imports

@Injectable()
export class CompanyService implements OnDestroy {
    private url = Environment.origin;
    private urlMainSearch = Environment.MAIN_SEARCH;
    private urlSearchAll = Environment.SEARCH_ALL;
    private headers = new Headers({
        'Accept': 'application/cp+json','Content-Type': 'application/json'
    });
    private headersFile = new Headers({
        'Accept': 'application/cp+json','Content-Type': 'multipart/form-data; boundary=something'
    });
    constructor(private http: Http,private jsonp: Jsonp) { }

    ngOnDestroy() {
        delete this.http;
    }

    buscarEmpresas(pesquisa: string): Observable<any> {
        return this.http.get(`${this.url}/companies/${pesquisa}/search`,{ headers: this.headers })
            .pipe(map((response) => response.json().response));
    }

    buscarEmpresasCache(pesquisa: string): Observable<any> {
        return this.http.get(`${this.url}/companies/search?texto=${StringUtils.unaccent(pesquisa)}`,{ headers: this.headers })
            .pipe(map((response) => response.json().response));
    }

    buscarEmpresasMicroServico(pesquisa: string): Observable<any> {
        return this.http.get(`${this.urlMainSearch}/main-search?texto=${StringUtils.unaccent(pesquisa)}`,{ headers: this.headers })
            .pipe(map((response) => response.json().response));
    }

    getEmpresa(id: number): Observable<Retorno<Empresa>> {
        return this.http.get(`${this.url}/companies/${id}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    getEmpresaByUrlLink(urlLink: string): Observable<Retorno<Empresa>> {
        return this.http.get(`${this.url}/companies/link/${urlLink}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    getEmpresaratings(id: number): Observable<Retorno<rating>> {
        return this.http.get(`${this.url}/companies/${id}/ratings`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<rating>(response.json())));
    }

    getoperadora(): Observable<Array<Empresa>> {
        return this.http.get(`${this.url}/companies/search/operadora/10/1`,{ headers: this.headers })
            .pipe(map((response) => response.json().map(empresa => new Empresa(empresa))));
    }

    getTopEmpresas(type: number): Observable<Retorno<Array<Empresa>>> {
        return this.http.get(`${this.url}/companies/top?type=${type}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<Empresa>>(response.json())));
    }

    buscarEmpresasPorTipo(tipo: number,pagina: number,tags: Array<number>,continentes: Array<number>,paises: Array<number>,cidades: Array<number>): Observable<Retorno<Array<Empresarating>>> {

        // if(!this.resolveUrlSearchBug()) {
        let url = `${this.url}/companies/searchtype?number=25&page=${pagina}&type=${tipo}`;
        if (tags && tags.length > 0) {
            const tag = `&tags=${tags.join(',')}`;
            url = url + tag;
        }
        if (continentes && continentes.length > 0) {
            const continente = `&continentes=${continentes.join(',')}`;
            url = url + continente;
        }
        if (paises && paises.length > 0) {
            const pais = `&paises=${paises.join(',')}`;
            url = url + pais;
        }
        if (cidades && cidades.length > 0) {
            const cidade = `&cidades=${cidades.join(',')}`;
            url = url + cidade;
        }
        return this.http.get(url,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<Empresarating>>(response.json())));
        // }
    }

    buscarTodasEmpresas(pagina: number,texto: string,tipos: Array<number>,localizacoes: Array<number>):
    Observable<Retorno<RankingTodasEmpresas>> {

        let url = `${this.urlSearchAll}/company-search-all?texto=${texto}&limit=25&offset=${pagina}`;
        if (tags && tags.length > 0) {
            const tag = `&tags=${tags.join(',')}`;
            url = url + tag;
        }
        if (localizacoes && localizacoes.length > 0) {
            const localizacao = `&localizacoes=${localizacoes.join(',')}`;
            url = url + localizacao;
        }
        if (tipos && tipos.length > 0) {
            const tipo = `&tipos=${tipos.join(',')}`;
            url = url + tipo;
        }
        return this.http.get(url,{ headers: this.headers })
            .pipe(map((response) => new Retorno<RankingTodasEmpresas>(response.json())));
    }

    buscarEmpresasSimilares(tipo: number,idEmpresaPesquisada: number): Observable<Retorno<Array<Empresa>>> {
        return this.http.get(`${this.url}/companies/random-searchtype?type=${tipo}&idEmpresaPesquisada=${idEmpresaPesquisada}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<Empresa>>(response.json())));
    }

    buscarMenuTags(tipo: number): Observable<Retorno<SuperMenu>> {
        // console.log(this.resolveUrlSearchBug());
        // if(!this.resolveUrlSearchBug()) {
        // console.log('Chamando service.........');
        return this.http.get(`${this.url}/companies/searchtype/filtro?type=${tipo}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<SuperMenu>(response.json())));
        // }
    }

    cadastrarEmpresa(empresa: Empresa,isByCadFornecedor: boolean = false): Observable<Retorno<Empresa>> {
        return this.http.post(`${this.url}/companies?isByCadFornecedor=${isByCadFornecedor}`,JSON.stringify(empresa),{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    cadastrarEmpresaPreCadastro(preCadastro: EmpresaPreCadastro): Observable<Retorno<Empresa>> {
        return this.http.post(`${this.url}/companies/pre-cadastro`,JSON.stringify(preCadastro),{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    adminCadastrarEmpresa(empresa: Empresa): Observable<Retorno<Empresa>> {
        return this.http.post(`${this.url}/companies/admin`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    alterarEmpresa(empresa: Empresa): Observable<Retorno<Empresa>> {
        return this.http.put(`${this.url}/companies`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    buscarTiposEmpresa(): Observable<Retorno<Array<Tipo>>> {
        return this.http.get(`${this.url}/categories`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<Tipo>>(response.json())));
    }

    buscarTipoEmpresa(tipo: number): Observable<Retorno<Tipo>> {
        return this.http.get(`${this.url}/company-types/${tipo}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Tipo>(response.json())));
    }

    buscarTipoEmpresaPorUrlLink(urlLink: string): Observable<Retorno<Tipo>> {
        if (this.http) {
            return this.http.get(`${this.url}/company-types/link/${urlLink}`,{ headers: this.headers })
                .pipe(map((response) => new Retorno<Tipo>(response.json())));
        }
    }

    atualizarStatus(codigo: number): Observable<any> {
        return this.http.put(`${this.url}/company-status`,JSON.stringify(codigo),{ headers: this.headers })
            .pipe(map((response) => response.json()));
    }

    apagarCategoria(id: number): Observable<any> {
        return this.http.delete(`${this.url}/company-types/${id}`,{ headers: this.headers })
            .pipe(map((response) => response.json()));
    }

    atualizarCategoria(categoria: Tipo): Observable<any> {
        return this.http.put(`${this.url}/company-types`,JSON.stringify(categoria),{ headers: this.headers })
            .pipe(map((response) => response.json()));
    }

    salvarCategoria(categoria: Tipo): Observable<any> {
        return this.http.put(`${this.url}/company-types`,{ headers: this.headers })
            .pipe(map((response) => response.json()));
    }

    vincularEmpresaUser(empresa: EmpresaUsuario): Observable<Retorno<EmpresaUsuario>> {
        return this.http.post(`${this.url}/company-users/associar`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<EmpresaUsuario>(response.json())));
    }

    adminBuscarTodos(page: number,size: number,sort: string,approved: boolean,pending: boolean,blocked: boolean,denied: boolean,deleted: boolean,nome: string,tipo: number): Observable<Retorno<Array<Empresa>>> {
        const params: URLSearchParams = new URLSearchParams();

        params.set('page',page.toString());
        params.set('size',size.toString());
        params.set('sort',sort);

        if (approved) {
            params.set('approved','true');
        }

        if (pending) {
            params.set('pending',pending.toString());
        }

        if (blocked) {
            params.set('blocked',blocked.toString());
        }

        if (denied) {
            params.set('denied',denied.toString());
        }

        if (deleted) {
            params.set('deleted',deleted.toString());
        }

        if (nome) {
            params.set('nome',nome);
        }

        if (tipo) {
            params.set('typeId',tipo.toString());
        }

        return this.http.get(`${this.url}/companies`,{ headers: this.headers,search: params.toString() })
            .pipe(map((response) => new Retorno<Array<Empresa>>(response.json())));
    }

    deletarEmpresa(id: number): Observable<Retorno<any>> {
        return this.http.delete(`${this.url}/companies/${id}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<any>(response.json())));
    }

    uploadXLSX(file: File) {
        const formData: FormData = new FormData();
        formData.append('file',file,file.name);
        return this.http.post(`${this.url}/companies/xls/`,formData,{ headers: this.headersFile })
            .pipe(map((response) => response.json()));
    }

    buscarEmpresaCNPJ8(cnpj: string): Observable<Retorno<EmpresaUsuario>> {
        return this.http.get(`${this.url}/companies/cnpj8/${cnpj}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<EmpresaUsuario>(response.json())));
    }

    adminBuscarEmpresasPorTipo(page: number,id: number,nome: string): Observable<Retorno<Empresa>> {
        let t = null;
        try {
            t = tipos.join(',');
        } catch {
            t = tipos;
        }

        let url = `${this.url}/companies/buscar-tipo?page=${page}&size=${size}&sort=${sort}&tipos=${t}`;

        if (nome) {
            url = url + `&nome=${nome}`;
        }

        if (id) {
            url = url + `&id=${id}`;
        }

        return this.http.get(url,{ headers: this.headers })
            .pipe(map((response) => new Retorno<Empresa>(response.json())));
    }

    public buscarResumoFornecedor(referencia: string): Observable<Retorno<ResumoFornecedor>> {
        return this.http.get(`${this.url}/company-dashboard/resumo/fornecedor/referencia/${referencia}`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<ResumoFornecedor>(response.json())));
    }

    public buscarResumoAgencia(): Observable<Retorno<ResumoAgencia>> {
        return this.http.get(`${this.url}/company-dashboard/resumo/agencia`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<ResumoAgencia>(response.json())));
    }

    public buscarBarraCamposPreenchidos(): Observable<Retorno<number>> {
        return this.http.get(`${this.url}/company-dashboard/barra-campos`,{ headers: this.headers })
            .pipe(map((response) => new Retorno<number>(response.json())));
    }

    public salvarLocalizacoes(id: number,locais: Array<ApiLoacalizacaoCidadecp>):
        Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        return this.http.post(`${this.url}/company-localizacao/salvar/${id}`,JSON.stringify(locais),{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<ApiLoacalizacaoCidadecp>>(response.json())));
    }

    public removerLocalizacao(id: number,local: ApiLoacalizacaoCidadecp):
        Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        return this.http.post(`${this.url}/company-localizacao/remover/${id}`,JSON.stringify(local),{ headers: this.headers })
            .pipe(map((response) => new Retorno<Array<ApiLoacalizacaoCidadecp>>(response.json())));
    }

    public adminBuscarLocalizacoes(page: number,sort: string): Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        const params: URLSearchParams = new URLSearchParams();
        params.set('page',sort);

        return this.http.get(`${this.url}/company-localizacao/admin-filtrar`,search: params.toString() })
            .pipe(map((response) => new Retorno<Array<ApiLoacalizacaoCidadecp>>(response.json())));
    }

    public buscarLocalizacoes(texto: string): Observable<any> {
        const params: URLSearchParams = new URLSearchParams();
        params.set('texto',texto.toString());
        return this.http.get(`${this.url}/company-localizacao`,search: params.toString() })
            .pipe(map((response) => response.json().response));
    }

    private resolveUrlSearchBug(): boolean {
        const url = window.location.pathname.split("/");
        if (url[1] !== 'empresas') {
            return true;
        }
    }

}

在（HttpClient）之后

import { Injectable,OnDestroy } from '@angular/core';
import { Observable } from 'rxjs';
import { HttpClient,HttpHeaders,HttpParams } from '@angular/common/http';
import { Environment } from '../app.component';
//my components imports


@Injectable()
export class CompanyService implements OnDestroy {
    private url = Environment.origin;
    private urlMainSearch = Environment.MAIN_SEARCH;
    private urlSearchAll = Environment.SEARCH_ALL;
    private headers = new HttpHeaders({
        'Accept': 'application/cp+json','Content-Type': 'application/json'
    });
    private headersFile = new HttpHeaders({
        'Accept': 'application/cp+json','Content-Type': 'multipart/form-data; boundary=something'
    });
    constructor(private http: HttpClient) { }

    ngOnDestroy() {
        delete this.http;
    }

    buscarEmpresas(pesquisa: string): Observable<any> {
        return this.http.get<any>(`${this.url}/companies/${pesquisa}/search`,{ headers: this.headers })
    }

    buscarEmpresasCache(pesquisa: string): Observable<any> {
        return this.http.get<any>(`${this.url}/companies/search?texto=${StringUtils.unaccent(pesquisa)}`,{ headers: this.headers })
    }

    buscarEmpresasMicroServico(pesquisa: string): Observable<any> {
        return this.http.get<any>(`${this.urlMainSearch}/main-search?texto=${StringUtils.unaccent(pesquisa)}`,{ headers: this.headers })
    }

    getEmpresa(id: number): Observable<Retorno<Empresa>> {
        return this.http.get<Retorno<Empresa>>(`${this.url}/companies/${id}`,{ headers: this.headers })
    }

    getEmpresaByUrlLink(urlLink: string): Observable<Retorno<Empresa>> {
        return this.http.get<Retorno<Empresa>>(`${this.url}/companies/link/${urlLink}`,{ headers: this.headers })
    }

    getEmpresaratings(id: number): Observable<Retorno<rating>> {
        return this.http.get<Retorno<rating>>(`${this.url}/companies/${id}/ratings`,{ headers: this.headers })
    }

    getoperadora(): Observable<Array<Empresa>> {
        return this.http.get<Array<Empresa>>(`${this.url}/companies/search/operadora/10/1`,{ headers: this.headers })
    }

    getTopEmpresas(type: number): Observable<Retorno<Array<Empresa>>> {
        return this.http.get<Retorno<Array<Empresa>>>(`${this.url}/companies/top?type=${type}`,{ headers: this.headers })
    }

    buscarEmpresasPorTipo(tipo: number,')}`;
            url = url + cidade;
        }
        return this.http.get<Retorno<Array<Empresarating>>>(url,{ headers: this.headers })
        // }
    }

    buscarTodasEmpresas(pagina: number,')}`;
            url = url + tipo;
        }
        return this.http.get<Retorno<RankingTodasEmpresas>>(url,{ headers: this.headers })
    }

    buscarEmpresasSimilares(tipo: number,idEmpresaPesquisada: number): Observable<Retorno<Array<Empresa>>> {
        return this.http.get<Retorno<Array<Empresa>>>(`${this.url}/companies/random-searchtype?type=${tipo}&idEmpresaPesquisada=${idEmpresaPesquisada}`,{ headers: this.headers })
    }

    buscarMenuTags(tipo: number): Observable<Retorno<SuperMenu>> {
        // console.log(this.resolveUrlSearchBug());
        // if(!this.resolveUrlSearchBug()) {
        // console.log('Chamando service.........');
        return this.http.get<Retorno<SuperMenu>>(`${this.url}/companies/searchtype/filtro?type=${tipo}`,{ headers: this.headers })
        // }
    }

    cadastrarEmpresa(empresa: Empresa,isByCadFornecedor: boolean = false): Observable<Retorno<Empresa>> {
        return this.http.post<Retorno<Empresa>>(`${this.url}/companies?isByCadFornecedor=${isByCadFornecedor}`,{ headers: this.headers })
    }

    cadastrarEmpresaPreCadastro(preCadastro: EmpresaPreCadastro): Observable<Retorno<Empresa>> {
        return this.http.post<Retorno<Empresa>>(`${this.url}/companies/pre-cadastro`,{ headers: this.headers })
    }

    adminCadastrarEmpresa(empresa: Empresa): Observable<Retorno<Empresa>> {
        return this.http.post<Retorno<Empresa>>(`${this.url}/companies/admin`,{ headers: this.headers })
    }

    alterarEmpresa(empresa: Empresa): Observable<Retorno<Empresa>> {
        return this.http.put<Retorno<Empresa>>(`${this.url}/companies`,{ headers: this.headers })
    }

    buscarTiposEmpresa(): Observable<Retorno<Array<Tipo>>> {
        return this.http.get<Retorno<Array<Tipo>>>(`${this.url}/categories`,{ headers: this.headers })
    }

    buscarTipoEmpresa(tipo: number): Observable<Retorno<Tipo>> {
        return this.http.get<Retorno<Tipo>>(`${this.url}/company-types/${tipo}`,{ headers: this.headers })
    }

    buscarTipoEmpresaPorUrlLink(urlLink: string): Observable<Retorno<Tipo>> {
        if (this.http) {
            return this.http.get<Retorno<Tipo>>(`${this.url}/company-types/link/${urlLink}`,{ headers: this.headers })
        }
    }

    atualizarStatus(codigo: number): Observable<any> {
        return this.http.put<any>(`${this.url}/company-status`,{ headers: this.headers })
    }

    apagarCategoria(id: number): Observable<any> {
        return this.http.delete<any>(`${this.url}/company-types/${id}`,{ headers: this.headers })
    }

    atualizarCategoria(categoria: Tipo): Observable<any> {
        return this.http.put<any>(`${this.url}/company-types`,{ headers: this.headers })
    }

    salvarCategoria(categoria: Tipo): Observable<any> {
        return this.http.put<any>(`${this.url}/company-types`,{ headers: this.headers })
    }

    vincularEmpresaUser(empresa: EmpresaUsuario): Observable<Retorno<EmpresaUsuario>> {
        return this.http.post<Retorno<EmpresaUsuario>>(`${this.url}/company-users/associar`,{ headers: this.headers })
    }

    adminBuscarTodos(page: number,tipo: number): Observable<Retorno<Array<Empresa>>> {
        const params: HttpParams = new HttpParams();

        params.set('page',tipo.toString());
        }

        return this.http.get<Retorno<Array<Empresa>>>(`${this.url}/companies`,params })
    }

    deletarEmpresa(id: number): Observable<Retorno<any>> {
        return this.http.delete<any>(`${this.url}/companies/${id}`,{ headers: this.headers })
    }

    uploadXLSX(file: File) {
        const formData: FormData = new FormData();
        formData.append('file',{ headers: this.headersFile })
    }

    buscarEmpresaCNPJ8(cnpj: string): Observable<Retorno<EmpresaUsuario>> {
        return this.http.get<Retorno<EmpresaUsuario>>(`${this.url}/companies/cnpj8/${cnpj}`,{ headers: this.headers })
    }

    adminBuscarEmpresasPorTipo(page: number,');
        } catch {
            t = tipos;
        }

        let url = `${this.url}/companies/buscar-tipo?page=${page}&size=${size}&sort=${sort}&tipos=${t}`;

        if (nome) {
            url = url + `&nome=${nome}`;
        }

        if (id) {
            url = url + `&id=${id}`;
        }

        return this.http.get<Retorno<Empresa>>(url,{ headers: this.headers })
    }

    public buscarResumoFornecedor(referencia: string): Observable<Retorno<ResumoFornecedor>> {
        return this.http.get<Retorno<ResumoFornecedor>>(`${this.url}/company-dashboard/resumo/fornecedor/referencia/${referencia}`,{ headers: this.headers })
    }

    public buscarResumoAgencia(): Observable<Retorno<ResumoAgencia>> {
        return this.http.get<Retorno<ResumoAgencia>>(`${this.url}/company-dashboard/resumo/agencia`,{ headers: this.headers })
    }

    public buscarBarraCamposPreenchidos(): Observable<Retorno<number>> {
        return this.http.get<Retorno<number>>(`${this.url}/company-dashboard/barra-campos`,{ headers: this.headers })
    }

    public salvarLocalizacoes(id: number,locais: Array<ApiLoacalizacaoCidadecp>):
        Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        return this.http.post<Retorno<Array<ApiLoacalizacaoCidadecp>>>(`${this.url}/company-localizacao/salvar/${id}`,{ headers: this.headers })
    }

    public removerLocalizacao(id: number,local: ApiLoacalizacaoCidadecp):
        Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        return this.http.post<Retorno<Array<ApiLoacalizacaoCidadecp>>>(`${this.url}/company-localizacao/remover/${id}`,{ headers: this.headers })
    }

    public adminBuscarLocalizacoes(page: number,sort: string): Observable<Retorno<Array<ApiLoacalizacaoCidadecp>>> {
        const params: HttpParams = new HttpParams();
        params.set('page',sort);

        return this.http.get<Retorno<Array<ApiLoacalizacaoCidadecp>>>(`${this.url}/company-localizacao/admin-filtrar`,params })
    }

    public buscarLocalizacoes(texto: string): Observable<any> {
        const params: HttpParams = new HttpParams();
        params.set('texto',texto.toString());
        return this.http.get<any>(`${this.url}/company-localizacao`,params })
    }

    private resolveUrlSearchBug(): boolean {
        const url = window.location.pathname.split("/");
        if (url[1] !== 'empresas') {
            return true;
        }
    }

}

解决方法

我假设变量this.http的类型为HttpClient。 HttpClient.get()的类型定义指出，options自变量具有一个可选属性params，其类型为：

params?: HttpParams | { [param: string]: string | string[]; };

它不能是单个string（这是params.toString()返回的内容）。它是strings的键值对象或HttpParams对象。

您可以直接传递params变量，因为它的类型为HttpParams。

代替

{ headers: this.headers,params: params.toString() }

就做

{ headers: this.headers,params }

但是params并非总是两种情况都为空吗？您可以初始化一个空对象，并且不添加任何内容（除非您省略了该部分）。

编辑：

看到完整的代码后，我可以解释参数为空的情况。

在URLSearchParams类上，set()方法是void方法，该方法使对象变异且不返回任何内容。在原始代码中，他们正在执行的操作是创建一个空对象，在其上设置一堆值，然后将其转换为字符串。 （我问这个问题是空的，因为带有params.set()的部分不是您的示例代码的一部分。）

(method) URLSearchParams.set(name: string,value: string): void

Sets the value associated to a given search parameter to the given value. If there were several values,delete the others.

HttpParams类的工作方式不同。它不会返回您设置的值，而是返回一个新实例。

(method) HttpParams.set(param: string,value: string): HttpParams

Replaces the value for a parameter.

@param param — The parameter name.

@param value — The new value.

@return — A new body with the new value.

但是，由于原始代码是使用void方法构建的，因此您对返回的值不做任何事情。每次设置内容时，都需要将params的值更改为返回值。将每个const params更改为let params，以便我们覆盖它。然后将所有对params.set()的呼叫替换为params = params.set()。像这样：

let params: HttpParams = new HttpParams();
params = params.set('page',page.toString());
params = params.set('size',size.toString());
params = params.set('sort',sort);
angularangularangular-httpclienttypescripttypescripttypescript

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