“部门”类型上不存在属性“employee”

Question

我正在制作一个初学者网站，到目前为止一切都很好，但我现在有一个奇怪的问题。

当在node.js控制台中键入ng serve --open以在localhost上启动站点时，我收到此消息 - >

src / app / department-detail / department-detail.component.ts（59,32）中的错误：错误TS2339：类型'部门'上不存在属性'employee'

我的代码是：

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { Location } from '@angular/common';
import { Department } from '../department';

import { DepartmentService }  from '../department.service';

import { Employee } from '../employee';
import { EmployeeService }  from '../employee.service';
@Component({
  selector: 'app-department-detail',
  templateUrl: './department-detail.component.html',
  styleUrls: ['./department-detail.component.css']
})
export class DepartmentDetailComponent implements OnInit {

  department : Department ;
  employees: Employee[];
  emp: Employee;
  average:number=1;


  constructor(private route: ActivatedRoute, private departmentService: DepartmentService, private location: Location,private employeeService: EmployeeService) { }

  ngOnInit() {
    this.getDepartment();

    this.getEmployees();
  }
  getDepartment(): void{
    const id = +this.route.snapshot.paramMap.get('id');
    this.departmentService.getDepartment(id).subscribe(department => this.department = department)
  }

  goBack(): void{
    this.location.back();
  }
  save(): void {
   this.departmentService.updateDepartment(this.department);
   this.goBack();
 }

 getEmployees(): void {
   this.employeeService.getEmployees().
   subscribe(employees => this.employees = employees);
 }

 Select(firstname:string){
   firstname = firstname.trim();
   if(!firstname){return;}
   this.employeeService.getEmployeeByName(firstname).subscribe(Employee => this.emp = Employee);
 }

 Delete():void{
   this.emp = null;
   this.average = 1;
 }
 Show():void{
   this.Select(this.department.employee); // this cant be true
   this.average = null;
 }


}

问题出在最后

显示功能

如果我删除员工并保存，然后再次添加它，那么边工作，但否则它不会。

这是我的部门组成部分。

export class Department{
    id: number;
    name: string;
    location: string;
    menId: number;
    static Id:number = 1;

    constructor(name: string,location: string) {
        this.id = Department.Id++;
        this.name = name;
        this.location = location;
        this.menId = 0;

    }

}

我不确定是否应该在Department组件中添加Employee类型的属性。

Answer 1

如果你看一下Department课程，你会注意到它实际上没有雇员财产。你应该添加一个这样的：

export class Department{
    id: number;
    name: string;
    location: string;
    menId: number;
    static Id:number = 1;
    employee: string;        // New employee property, type based on the Show method signature

    constructor(name: string,location: string) {
        this.id = Department.Id++;
        this.name = name;
        this.location = location;
        this.menId = 0;

    }

}

添加属性后，您可能会收到另一个错误，这次是在应用程序运行时，说firstname is undefined。如果你得到这个错误，它会被Select方法抛出，你首先尝试修剪名称，然后检查它是定义的还是非空的。为了防止错误，你应该简单地交换Select方法的第一行和第二行，使它们看起来像这样：

if(!firstname){ return; }
firstname = firstname.trim();