我的问题类似于这个问题，但我已经应用了答案，它仍然不起作用，我在数据库中存储数据时使用了一种稍微不同的方法。
员工模型类

public class Employee
    {
        [Key]
        public int EmployeeId { get; set; }

        [Required]
        public string FirstName { get; set; }
        [Required]
        public string LastName { get; set; }
}

键入与保存相关的脚本代码

private urlSaveEmployee = '/employee/save';

private save() {
        try {

            const employee = this.createEmployee();
            Util.request(this.urlSaveEmployee, 'post', 'json', (response) => {
                if (response != null) {
                    $.notify(response.message);
                    location.reload();
                } else {
                    $.notify(response.message);
                    console.error('Failed to get data #T7G985. Please try again.');
                }
            }, () => {
            }, employee);
        } catch (e) {
            console.error(e);
        }
    }

    private createEmployee() {
        try {

            const employee = {
                EmployeeId: $('#employee_id').val(),
                Firstname: $('#first_name').val(),
                Lastname: $('#last_name').val()
            };
            return employee;
        } catch (e) {
            console.error(e);
        }
    }

保存按钮视图代码

<tr>
                <td style="width: 100px">First Name*</td>
                <td>
                    <input type="hidden" id="employee_id" value="@Employee.EmployeeId" />
                    <input class="form-control-sm w-100" id="first_name" value="@Employee.FirstName" autocomplete="off" />
                </td>
            </tr>
            <tr>
                <td style="width: 100px">Last Name*</td>
                <td>
                    <input class="form-control-sm w-100" id="last_name" value="@Employee.LastName" autocomplete="off" />
                </td>
            </tr>

<button type="button" class="btn btn-sm btn-outline-primary employee-form-save" id="save_form">
                        <i class="fa fa-floppy-o" style="margin-right:5px"></i>
                        Save
                    </button>

与保存相关的控制器代码

[HttpPost("employee/save")]
        public async Task<IActionResult> SaveEmployee(Employee employee) {
            try
            {
                Employee employeeFromDb = await _db.Employees.FirstOrDefaultAsync(e => e.EmployeeId == employee.EmployeeId);

                if (employeeFromDb == null)
                {
                    _db.Employees.Add(employee);
                    _db.SaveChanges();
                    return Json(new { success = true, message = "Saved Successfully" });
                } else {
                    _db.Employees.Update(employee);
                    _db.SaveChanges();
                    return Json(new { success = true, message = "Updated Successfully" });
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return Json(new { success = false, message = "Error while saving" });
            }
        }

当我点击保存按钮时，它会重新加载页面而不做任何更改。我添加了断点，然后 employeeFromDb 显然是在 .Update 但它只是刷新页面，数据库保持不变。以下是该断点处的屏幕截图：