错误TypeError：无法读取null的属性“名称”

Question

错误TypeError：无法读取此文件中null的属性name：

import {Component, Input, OnInit} from '@angular/core';
import {Project} from '../../project';
import {Candidate} from '../../../candidates/candidate';
import {User} from '../../../../shared/services/user';
import {Client} from '../../../clients/client';
import {CandidatesService} from '../../../candidates/candidates.service';
import {ProjectsService} from '../../projects.service';
import {ClientService} from '../../../clients/client.service';
import {Job} from '../../../../shared/services/job';
import {UsersService} from '../../../../shared/services/users.service';
import {JobsService} from '../../../../shared/services/job.service';

@Component({
  selector: 'app-all-projects-add',
  templateUrl: './all-projects-add.component.html',
  styleUrls: ['./all-projects-add.component.scss']
})
export class AllProjectsAddComponent implements OnInit {
    @Input() cValue;
    @Input() dValue;
    project: Project;
    users: User[];
    candidates: Candidate[];
    clients: Client[];
    jobs: Job[];
    success = false;
    failure = false;

    constructor(private projectsService: ProjectsService,
                private userService: UsersService,
                private clientService: ClientService,
                private candidatesService: CandidatesService,
                private jobsService: JobsService) {

        this.userService.getItemsList().subscribe(users => this.users = users);
        this.clientService.getItemsList().subscribe(clients => this.clients = clients);
        // this.candidatesService.getItemsList().subscribe(candidates => this.candidates = candidates);
        this.jobsService.getItemsList().subscribe(jobs => this.jobs = jobs);

        this.project = new Project();
    }

    ngOnInit() {
    }

    validation(): boolean {
        if (!this.project.candidatesNo) {
            return false
        }
        return true;
    }

    addProject() {
        console.log(this.project);

        if (this.validation()) {
            this.clientService.getItem(this.project.client_key).subscribe(client => {


                this.userService.getItem(this.project.user_key).subscribe(user => {
                    this.project.user_name = user.name;
                    this.project.city = user.city;

                    // we do this for ng2-smart-table
                    this.project.startTime = this.project.startTime.year + '/' +
                        this.project.startTime.month + '/' +
                        this.project.startTime.day;

                    this.project.endTime = this.project.endTime.year + '/' +
                        this.project.endTime.month + '/' +
                        this.project.endTime.day;

                    console.log('Project added successfully...');
                    this.success = true;
                    this.projectsService.createItem(this.project);
                    setTimeout(function () {
                        this.success = false;
                        this.dValue('Cross click');
                        this.project = new Project();
                    }.bind(this), 1500);
                })


            })
        } else {
            this.failure = true;
            console.log('Error adding new project...');
            setTimeout(function () {
                this.failure = false;
            }.bind(this), 1500);
        }
    }



}

这是Angular4，Angularfire2和firebase。我在这里也让您查看user.ts文件。

// Roles interface
export interface Roles {
    recruiter: boolean;
    client: boolean;
    admin: boolean;
}


// User class
export class User {
    $key: string;
    $key2: string;
    email: string;
    name: string;
    displayName: string;
    city: string;
    profile = false;
    admin = true;
    roles: Roles;
    uid: string;


constructor() {
    this.name = '';
    this.city = '';
    this.displayName = '';
    }
}

当我尝试将新项目添加到列表中时，出现此错误，并且不明白为什么。我的应用程序上有一个名为event的相似实体，具有与用户auth.uid绑定的相同模型，并且效果很好。这是一个问题。如果有人可以解释为什么它不起作用，请给我真正的感谢。

  

“错误TypeError：无法读取null的属性'名称'”