Argument of type ‘Object’ is not assignable to parameter of type ‘string’ - Ionic Angular

问题

Trying to parse with JSON but i get this error: Argument of type 'Object' is not assignable to parameter of type 'string'.

import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-uploader',
  templateUrl: './uploader.page.html',
  styleUrls: ['./uploader.page.scss'],
})
export class UploaderPage implements OnInit {

  imageURL: string
  constructor(public http: HttpClient) { }

  ngOnInit() {
  }

  fileChanged(event) {
    const files = event.target.files
    const data = new FormData()
    data.append('file', files[0])
    data.append('UPLOADCARE_STORE', '1')
    data.append('UPLOADCARE_PUB_KEY', '12d3f0b0b65cb448aa6b')

    this.http.post('https://upload.uploadcare.com/base/', data).subscribe(event => {
      console.log(event)
      this.imageURL = JSON.parse(event).file
    })
  }


}

In the line this.imageURL = JSON.parse(event).file under (event) i get that error. What could be the cause and how to fix it.

The HTML :

<ion-header>
  <ion-toolbar>
    <ion-title>Upload Image</ion-title>
  </ion-toolbar>
</ion-header>

<ion-content padding>
  <div class="camera"> </div>
  <input type="file" (change)="fileChanged($event)"/>

  <img *ngIf="imageURL" src="https://ucarecdn.com/{{ imageURL}}/"/>
</ion-content>

回答1:

You are close. It appears the response from the POST request is already in JSON format. You don't need the JSON.parse() here. Try the following

this.http.post('https://upload.uploadcare.com/base/', data).subscribe(
  event => {
    this.imageURL = event.file;
  },
  error => { // handle error }
);

It is also good practice to make the actual HTTP request in a service and to handle the error in the subscription.

来源：https://stackoverflow.com/questions/61448660/argument-of-type-object-is-not-assignable-to-parameter-of-type-string-ioni

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