add-employee.html

<div class="col-md-6 offset-md-3">
    <h3> Create Employee </h3>
    <form (ngSubmit) = "onSubmit()">

        <div class="form-group">
            <label>Name</label>
            <input type="text" class ="form-control" id = "employeename"
                [(ngModel)] = "employee.employeename" name = "employeename">
        </div>

        <div class="form-group">
            <label>Age</label>
            <input  class ="form-control" id = "age"
                [(ngModel)] = "employee.age" name = "age">
        </div>

        <button class = "btn btn-success" type ="submit">Submit</button>

    </form>
</div>

add-employee.ts

import { Component, OnInit } from '@angular/core';
import { Employee } from '../employee';
import { EmployeeserviceService } from '../employeeservice.service';
import { NgForm } from '@angular/forms';

@Component({
  selector: 'app-add-employee',
  templateUrl: './add-employee.component.html',
  styleUrls: ['./add-employee.component.css']
})
export class AddEmployeeComponent implements OnInit {

  employee !: Employee;

  constructor(private employeeService:EmployeeserviceService) { }

  ngOnInit(): void {
  }

  onSubmit(){
    console.log(this.employee);

    this.employeeService.saveEmployee(this.employee).subscribe(data=>{
      console.log(data);
    })
  }

}

我是新的Angular 和我试图创建一个样本员工CRUD应用程序的动手经验。但在创建POST API创建我得到：
无法读取属性employeename
我不知道我哪里做错了，有人能帮我解决这个问题吗？
先谢了。