angular5 和 http GET 查询参数 - 看起来像专用对象（HttpParams 或 UrlSearchParams）不起作用

Question

I have a strange problem I cannot understand. Here is the code calling REST endpoint:

this.http.get<AllApplicationType[]>(environment.SUDS_API_SERVICE_URL + environment.SUDS_ALL_APPLICATIONS_URL, this.setQueryParams(page, size)).toPromise() ...

where setQueryParams function look like this:

setQueryParams(page?: number, size?: number): {} {
const startFrom = page * size + 1;
const params = new HttpParams();
params.set('startFrom', startFrom.toString());
params.set('maxRecords', size.toString());
return params;

}

When the request comes to my backend query params are null, somehow they are not being passed over but why ? Is this not the right method or what ?

Answer 1

It just occurred that using HttpParams or URLSearchParams objects do not work at all. All tries with these 2 failed in my case. The only way is to build parameters explicitly like this:

setRequestParams(page?: number, size?: number): {} {
const startFrom = page * size + 1;
const params = {'startFrom': startFrom.toString(), 'maxRecords': size.toString()};
const options = {params: params};
return options;

}

Well I beleive this is a bug in Angular HttpClient.