Javascript 角度-无法读取属性';id';未定义的
每当我尝试创建新票证时,都会收到以下错误消息: 无法读取未定义的属性“id” 这是我的thread.service.ts,我在其中使用AddTicket方法创建票据:Javascript 角度-无法读取属性';id';未定义的,javascript,angular,ionic-framework,firebase-realtime-database,Javascript,Angular,Ionic Framework,Firebase Realtime Database,每当我尝试创建新票证时,都会收到以下错误消息: 无法读取未定义的属性“id” 这是我的thread.service.ts,我在其中使用AddTicket方法创建票据: addTicket( id: string, heading: string, user: string, date: Date, description: string, likeCount: number, timeLeft: number){ const newTicket = new Threads (
addTicket(
id: string,
heading: string,
user: string,
date: Date,
description: string,
likeCount: number,
timeLeft: number){
const newTicket = new Threads
(
id,
heading,
user,
new Date(date),
description,
likeCount,
timeLeft
);
let generatedId: string;
return this.http
.post<{ name: string }>(
'https://ionic-angular-a0570.firebaseio.com/all-tickets.json',
{
...newTicket,
id: Math.random().toString()
}
)
.pipe(
switchMap(resData => {
generatedId = resData.name;
return this.tickets;
}),
take(1),
tap(tickets => {
newTicket.id = generatedId;
this._tickets.next(tickets.concat(newTicket));
})
);
}
这是my threads.model.ts(如果有帮助):
export class Threads {
constructor(
public id: string,
public heading: string,
public user: string,
public date: Date,
public description: string,
public likeCount: number,
public timeLeft: number
){}}
new-thread.page.ts:
onCreateTicket(){
this.threadService.addTicket(this.threads.id, this.heading, this.registerService.user, this.threadService.getDate(), this.description, +this.threadService.getLikes(), +12).subscribe();
import { Component, OnInit } from '@angular/core';
import { ThreadsService } from '../main/departmentforum/threads/threads.service';
import { NavController } from '@ionic/angular';
import { RegisterService } from '../register/register.service';
import { Threads } from '../main/departmentforum/threads/threads.model';
@Component({
selector: 'app-new-thread',
templateUrl: './new-thread.page.html',
styleUrls: ['./new-thread.page.scss'],
})
export class NewThreadPage implements OnInit {
heading: string;
description: string;
businessforum: string;
departmentforum: string;
threads: Threads;
constructor(private navController: NavController, private threadService: ThreadsService, public registerService: RegisterService) {}
ngOnInit() {
}
onCreateTicket(){
this.threadService.addTicket(this.threads.id, this.heading, this.registerService.user, this.threadService.getDate(), this.description, +this.threadService.getLikes(), +12).subscribe();
this.navController.navigateBack('main/departmentforum/threads');
}
}
thread.model.ts:
export class Threads {
constructor(
public id: string,
public heading: string,
public user: string,
public date: Date,
public description: string,
public likeCount: number,
public timeLeft: number
){}}
new-thread.page.ts中的
threads
变量已声明,但从未初始化。它应该用一些数据初始化。例如
threads: Threads = new Threads(
'0',
'',
'',
new Date((new Date()).getTime() + 24*60*60*1000),
'',
null,
null
);
工作示例:您能说出引发错误的行吗?@MichaelD NewThreadPage.html:48错误类型错误:无法读取Object.eval[as handleEvent](NewThreadPage.html:48)中NewThreadPage.onCreateTicket(new thread.page.ts:26)的undefined属性“id”(新线程方法尚未初始化。你确定它是在调用之前定义的吗?@MichaelD我以为this.threads来自模型,只是一个模板。。所以我想我还没有初始化它。我如何或在哪里可以这样做?如果不查看new-thread.page.ts或它的模板,我就不能完全确定这一点。