如何将JSON转换为angular2中的查询字符串？

Question

我是Angular2的新手.我有一个JSON对象,如下所示:

var options = {
  param1: "parama1",
  param2: "parama2",
  param3: "parama3"
};

应转换为查询字符串并附加到外部URL以重定向页面,如下所示:

ngOnInit(){
     window.location.href = someurl?param1=param1&param2=param2&param3=param3;
}

我正在寻找一种方法将其转换为查询字符串.在JQuery $.param()和AngularJS $httpParamSerializerJQLike()中都有这个.我搜索过,但我一无所获.我想知道有没有办法在angular2中做到这一点.

Answer 1

没有字符串concats的更"官方"方法:

import {URLSearchParams} from '@angular/http'
let options = {
  param1: "param1",
  param2: "param2",
  param3: "param3"
};

let params = new URLSearchParams();
for(let key in options){
    params.set(key, options[key]) 
}

console.log("http://someUrl?" + params.toString());

顺便说一下,这会自动编码.

Answer 2

您可以使用HttpParams

import { HttpParams } from '@angular/common/http';

new HttpParams({fromObject: yourObject}).toString()

Answer 3

此解决方案适用于大多数复杂类型

任何人都想知道如何做到这一点,我写了一个扩展,应该使用c#.Net Core 1.1和Typescript 2.2.2 WebApi看起来像这样.

请记住在您使用它的地方也要包含这两个导入

import { URLSearchParams } from '@angular/http';
import 'rxjs/add/operator/map'

export class QueryStringBuilder {
    static BuildParametersFromSearch<T>(obj: T): URLSearchParams {
        let params: URLSearchParams = new URLSearchParams();

        if (obj == null)
        {
            return params;
        }

        QueryStringBuilder.PopulateSearchParams(params, '', obj);

        return params;
    }

    private static PopulateArray<T>(params: URLSearchParams, prefix: string, val: Array<T>) {
        for (let index in val) {
            let key = prefix + '[' + index + ']';
            let value: any = val[index];
            QueryStringBuilder.PopulateSearchParams(params, key, value);
        }
    }

    private static PopulateObject<T>(params: URLSearchParams, prefix: string, val: T) {
        const objectKeys = Object.keys(val) as Array<keyof T>;

        if (prefix) {
            prefix = prefix + '.';
        }

        for (let objKey of objectKeys) {

            let value = val[objKey];
            let key = prefix + objKey;

            QueryStringBuilder.PopulateSearchParams(params, key, value);
        }
    }

    private static PopulateSearchParams<T>(params: URLSearchParams, key: string, value: any) {
        if (value instanceof Array) {
            QueryStringBuilder.PopulateArray(params, key, value);
        }
        else if (value instanceof Date) {
            params.set(key, value.toISOString());
        }
        else if (value instanceof Object) {
            QueryStringBuilder.PopulateObject(params, key, value);
        }
        else {
            params.set(key, value.toString());
        }
    }

}

这适用于我目前使用的所有复杂类型.