Angular14 14:在类型‘void’..ts(2339)上不存在属性“订阅”。

Question

我得到了这个错误: TS2339:属性‘订阅’在'void‘类型上不存在。

contacts.component.ts

import { Component, OnInit } from '@angular/core';
import { NgForm } from '@angular/forms';
import { Observable } from 'rxjs';
import { ContactsService } from '../contacts.service';

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

  constructor(public contactService:ContactsService) { }
  
  msgTrue=false;
  
  updateContact(contactId: number){
    const newData={id:contactId,firstName:'Roa',lastName:'Hugo'};
    this.contactService.updateContact(contactId,newData).subscribe(data=>{
      this.msgTrue=true;
    });
    
  }
}

contacts.service.ts

import { Injectable } from '@angular/core';
import { HttpClient,HttpHeaders,HttpParams } from '@angular/common/http';

@Injectable({
  providedIn: 'root'
})
export class ContactsService {
  constructor(private httpClient:HttpClient) { }

  updateContact(contactId:number,updateBody:any){
    const endpoint='http://localhost:3000/contacts/'+contactId;
    this.httpClient.put(endpoint,updateBody);
  }
}

tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "forceConsistentCasingInFileNames": true,
    "strict": false,
    "noImplicitOverride": true,
    "noPropertyAccessFromIndexSignature": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "sourceMap": true,
    "declaration": false,
    "downlevelIteration": true,
    "experimentalDecorators": true,
    "moduleResolution": "node",
    "importHelpers": true,
    "target": "es2020",
    "module": "es2020",
    "lib": [
      "es2020",
      "dom"
    ]
  },
  "angularCompilerOptions": {
    "enableI18nLegacyMessageIdFormat": true,
    "strictInjectionParameters": true,
    "strictInputAccessModifiers": true,
    "strictTemplates": true
  }
}

我在contacts.component.ts上得到了错误

行: this.contactService.updateContact(contactId，newData).subscribe(data=>{

错误TS2339:属性“订阅”在类型'void‘上不存在。

我知道“订阅”属性上有很多问题在'void‘类型中不存在，但它们似乎都是通过输入“返回”请求来解决的；我尝试了这个解决方案，但是它不起作用。

Answer 1

这可能是因为您的服务函数不返回可观察到的。您需要从updateContract返回可观察到的：

updateContact(contactId:number, updateBody:any): Observable<Contract>{
    const endpoint='http://localhost:3000/contacts/'+contactId;
    return this.httpClient.put<Contract>(endpoint,updateBody);
}