C# ASP.NET Core 2.0防止重复条目
我对ASP.NET核心MVC非常陌生。我正在使用ASP.NET Core 2.0、C#、EntityFrameworkCore代码优先和SQL Server 2016。我设法让我的积垢操作在需要时工作 但是，我需要帮助防止用户在我的表单上注册多次。如果可能的话，我希望检查/防止控制器端代码中的重复条目，而不是数据库中的重复条目 我附上我的代码，我现在有，如果有人可以帮助。提前谢谢你 型号C# ASP.NET Core 2.0防止重复条目,c#,asp.net-core,asp.net-core-mvc,asp.net-core-2.0,C#,Asp.net Core,Asp.net Core Mvc,Asp.net Core 2.0,我对ASP.NET核心MVC非常陌生。我正在使用ASP.NET Core 2.0、C#、EntityFrameworkCore代码优先和SQL Server 2016。我设法让我的积垢操作在需要时工作 但是，我需要帮助防止用户在我的表单上注册多次。如果可能的话，我希望检查/防止控制器端代码中的重复条目，而不是数据库中的重复条目 我附上我的代码，我现在有，如果有人可以帮助。提前谢谢你 型号 public class Employee { public int EmployeeID { ge
public class Employee
{
public int EmployeeID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int DepartmentID { get; set; }
public Department Department { get; set; }
public int AppointmentID { get; set; }
public Appointment Appointment { get; set; }
}
public class Department
{
public int DepartmentID { get; set; }
public string Name { get; set; }
public ICollection<Employee> Employees { get; set; }
}
public class Appointment
{
public int AppointmentID { get; set; }
public string TimeSlot { get; set; }
public ICollection<Employee> Employees { get; set; }
}
public class EmployeeFormVM
{
public int EmployeeID { get; set; }
[Required(ErrorMessage = "Please enter your First Name")]
[Display(Name = "First Name")]
[StringLength(50)]
public string FirstName { get; set; }
[Required(ErrorMessage = "Please enter your Last Name")]
[Display(Name = "Last Name")]
[StringLength(50)]
public string LastName { get; set; }
[Required(ErrorMessage = "Please select your Department")]
[Display(Name = "Department")]
public int DepartmentID { get; set; }
public IEnumerable<Department> Departments { get; set; }
[Required(ErrorMessage = "Please select your Appointment")]
[Display(Name = "Appointment")]
public int AppointmentID { get; set; }
public IEnumerable<Appointment> Appointments { get; set; }
}
公共类员工
{
public int EmployeeID{get；set；}
公共字符串名{get；set；}
公共字符串LastName{get；set；}
public int DepartmentID{get；set；}
公共部门部门{get；set；}
公共指定ID{get；set；}
公开约会{get；set；}
}
公共课系
{
public int DepartmentID{get；set；}
公共字符串名称{get；set；}
公共ICollection雇员{get；set；}
}
公开课任命
{
公共指定ID{get；set；}
公共字符串时隙{get；set；}
公共ICollection雇员{get；set；}
}
public class Employee
{
public int EmployeeID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int DepartmentID { get; set; }
public Department Department { get; set; }
public int AppointmentID { get; set; }
public Appointment Appointment { get; set; }
}
public class Department
{
public int DepartmentID { get; set; }
public string Name { get; set; }
public ICollection<Employee> Employees { get; set; }
}
public class Appointment
{
public int AppointmentID { get; set; }
public string TimeSlot { get; set; }
public ICollection<Employee> Employees { get; set; }
}
public class EmployeeFormVM
{
public int EmployeeID { get; set; }
[Required(ErrorMessage = "Please enter your First Name")]
[Display(Name = "First Name")]
[StringLength(50)]
public string FirstName { get; set; }
[Required(ErrorMessage = "Please enter your Last Name")]
[Display(Name = "Last Name")]
[StringLength(50)]
public string LastName { get; set; }
[Required(ErrorMessage = "Please select your Department")]
[Display(Name = "Department")]
public int DepartmentID { get; set; }
public IEnumerable<Department> Departments { get; set; }
[Required(ErrorMessage = "Please select your Appointment")]
[Display(Name = "Appointment")]
public int AppointmentID { get; set; }
public IEnumerable<Appointment> Appointments { get; set; }
}
公共类EmployeeFormVM
{
public int EmployeeID{get；set；}
[必需（ErrorMessage=“请输入您的名字”）]
[显示（Name=“First Name”）]
[长度（50）]
公共字符串名{get；set；}
[必需（ErrorMessage=“请输入您的姓氏”）]
[显示（Name=“Last Name”）]
[长度（50）]
公共字符串LastName{get；set；}
[必需（ErrorMessage=“请选择您的部门”）]
[显示（Name=“Department”）]
public int DepartmentID{get；set；}
公共IEnumerable部门{get；set；}
[必需（ErrorMessage=“请选择您的约会”）]
[显示（Name=“约会”）]
公共指定ID{get；set；}
公共IEnumerable约会{get；set；}
}
public class WinTenDbContext : DbContext
{
public WinTenDbContext(DbContextOptions<WinTenDbContext> options) : base(options)
{
}
public DbSet<Employee> Employees { get; set; }
public DbSet<Department> Departments { get; set; }
public DbSet<Appointment> Appointments { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Employee>()
.HasKey(e => e.EmployeeID);
modelBuilder.Entity<Employee>()
.Property(e => e.FirstName)
.HasColumnType("varchar(50)")
.HasMaxLength(50)
.IsRequired();
modelBuilder.Entity<Employee>()
.Property(e => e.LastName)
.HasColumnType("varchar(50)")
.HasMaxLength(50)
.IsRequired();
modelBuilder.Entity<Department>()
.HasKey(d => d.DepartmentID);
modelBuilder.Entity<Department>()
.Property(d => d.Name)
.HasColumnType("varchar(50)")
.HasMaxLength(50);
modelBuilder.Entity<Appointment>()
.HasKey(a => a.AppointmentID);
modelBuilder.Entity<Appointment>()
.Property(a => a.TimeSlot)
.HasColumnType("varchar(50)")
.HasMaxLength(50);
}
}
公共类WinTenDbContext:DbContext
{
公共WinTenDbContext（DbContextOptions选项）：基本（选项）
{
}
公共数据库集雇员{get；set；}
公共数据库集部门{get；set；}
公共数据库集约会{get；set；}
模型创建时受保护的覆盖无效（ModelBuilder ModelBuilder）
{
modelBuilder.Entity（）
.HasKey（e=>e.EmployeeID）；
modelBuilder.Entity（）
.Property（e=>e.FirstName）
.HasColumnType（“varchar（50）”）
.HasMaxLength（50）
.IsRequired（）；
modelBuilder.Entity（）
.Property（e=>e.LastName）
.HasColumnType（“varchar（50）”）
.HasMaxLength（50）
.IsRequired（）；
modelBuilder.Entity（）
.HasKey（d=>d.DepartmentID）；
modelBuilder.Entity（）
.Property（d=>d.Name）
.HasColumnType（“varchar（50）”）
.HasMaxLength（50）；
modelBuilder.Entity（）
.HasKey（a=>a.AppointmentID）；
modelBuilder.Entity（）
.Property（a=>a.TimeSlot）
.HasColumnType（“varchar（50）”）
.HasMaxLength（50）；
}
}
public class EmployeesController : Controller
{
private readonly WinTenDbContext _context;
public EmployeesController(WinTenDbContext context)
{
_context = context;
}
// GET: Employees
public async Task<IActionResult> Index()
{
//return View(await _context.Employees.ToListAsync());
var webAppDbContext = _context.Employees.Include(d => d.Department).Include(a => a.Appointment);
return View(await webAppDbContext.ToListAsync());
}
// GET: Employees/Details/5
public async Task<IActionResult> Details(int? id)
{
if (id == null)
{
return NotFound();
}
var employee = await _context.Employees
.SingleOrDefaultAsync(m => m.EmployeeID == id);
if (employee == null)
{
return NotFound();
}
return View(employee);
}
// GET: Employees/Create
public IActionResult Create()
{
var departments = _context.Departments.ToList();
var appointments = _context.Appointments.ToList();
var viewModel = new EmployeeFormVM
{
Departments = departments,
Appointments = appointments
};
return View(viewModel);
}
// POST: Employees/Create
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(EmployeeFormVM employee)
{
if (ModelState.IsValid)
{
var emp = new Employee();
{
emp.FirstName = employee.FirstName;
emp.LastName = employee.LastName;
emp.DepartmentID = employee.DepartmentID;
emp.AppointmentID = employee.AppointmentID;
}
_context.Add(emp);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
else
{
employee.Departments = _context.Departments.ToList();
employee.Appointments = _context.Appointments.ToList();
return View(employee);
}
}
// GET: Employees/Edit/5
public async Task<IActionResult> Edit(int? id)
{
if (id == null)
{
return NotFound();
}
var employeevm = new EmployeeFormVM();
{
Employee employee = await _context.Employees.SingleOrDefaultAsync(m => m.EmployeeID == id);
if (employee == null)
{
return NotFound();
}
employeevm.EmployeeID = employee.EmployeeID;
employeevm.FirstName = employee.FirstName;
employeevm.LastName = employee.LastName;
// Retrieve list of Departments
var departments = _context.Departments.ToList();
employeevm.Departments = departments;
// Set the selected department
employeevm.DepartmentID = employee.DepartmentID;
// Retrieve list of Appointments
var appointments = _context.Appointments.ToList();
employeevm.Appointments = appointments;
// Set the selected department
employeevm.AppointmentID = employee.AppointmentID;
}
return View(employeevm);
}
// POST: Employees/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(EmployeeFormVM vmEdit)
{
if (ModelState.IsValid)
{
Employee employee = _context.Employees.SingleOrDefault(e => e.EmployeeID == vmEdit.EmployeeID);
if (employee == null)
{
return NotFound();
}
employee.FirstName = vmEdit.FirstName;
employee.LastName = vmEdit.LastName;
employee.DepartmentID = vmEdit.DepartmentID;
employee.AppointmentID = vmEdit.AppointmentID;
try
{
_context.Update(employee);
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!EmployeeExists(vmEdit.EmployeeID))
{
return NotFound();
}
else
{
throw;
}
}
return RedirectToAction(nameof(Index));
}
return View(vmEdit);
}
// GET: Employees/Delete/5
public async Task<IActionResult> Delete(int? id)
{
if (id == null)
{
return NotFound();
}
var employee = await _context.Employees
.SingleOrDefaultAsync(m => m.EmployeeID == id);
if (employee == null)
{
return NotFound();
}
return View(employee);
}
// POST: Employees/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public async Task<IActionResult> DeleteConfirmed(int id)
{
var employee = await _context.Employees.SingleOrDefaultAsync(m => m.EmployeeID == id);
_context.Employees.Remove(employee);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
private bool EmployeeExists(int id)
{
return _context.Employees.Any(e => e.EmployeeID == id);
}
}
公共类EmployeesController:控制器
{
私有只读WinTenDbContext\u上下文；
公共EmployeesController（WinTenDbContext上下文）
{
_上下文=上下文；
}
//获取：员工
公共异步任务索引（）
{
//返回视图（wait_context.Employees.toListSync（））；
var webAppDbContext=_context.Employees.Include（d=>d.Department）.Include（a=>a.Appointment）；
返回视图（等待webAppDbContext.ToListAsync（））；
}
//获取：员工/详细信息/5
公共异步任务详细信息（int？id）
{
if（id==null）
{
返回NotFound（）；
}
var employee=await\u context.Employees
.SingleOrDefaultAsync（m=>m.EmployeeID==id）；
if（employee==null）
{
返回NotFound（）；
}
返回视图（员工）；
}
//获取：员工/创建
public IActionResult Create（）
{
var departments=_context.departments.ToList（）；
var appoints=_context.appoints.ToList（）；
var viewModel=新员工表单VM
{
部门=部门，
约会=约会
};
返回视图（viewModel）；
}
//职位：员工/创建
//若要防止套印攻击，请启用要绑定到的特定属性，例如
//更多详细信息请参见http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
公共异步任务创建（EmployeeFormVM员工）
{
if（ModelState.IsValid）
{
var emp=新员工（）；
{
emp.FirstName=employee.FirstName；
emp.LastName=employee.LastName；
emp.DepartmentID=employee.DepartmentID；
emp.AppointmentID=employee.AppointmentID；
}
_添加（emp）；
wait_context.SaveChangesAsync（）；
返回重定向到操作（名称（索引））；
}
其他的
{
employee.Departments=_context.Departments.ToList（）；
employee.Appointments=_context.appoints.ToList（）；
返回视图（员工）；
}
}
//获取：雇员/编辑/5
公共异步任务编辑（int？id）
{
if（id==null）
{
返回NotFound（）；
}
var employeevm=new EmployeeFormVM（）；
{
Employee=await_context.Employees.SingleOrDefaultAsync（m=>m.EmployeeID==id）；
if（employee==null）
{
返回NotFound（）；
}
employeevm.EmployeeID
Employee existingEmployee = await _context.Employees.SingleOrDefaultAsync(
m => m.FirstName == employee.FirstName && m.LastName == employee.LastName);
if (existingEmployee != null)
{
// The employee already exists.
// Do whatever you need to do - This is just an example.
ModelState.AddModelError(string.Empty, "This employee already exists.");
employee.Departments = _context.Departments.ToList();
employee.Appointments = _context.Appointments.ToList();
return View(employee);
}
// Your existing code for creating a new employee.
@using (Html.BeginForm("Create", "Employees"))
{
@Html.ValidationSummary(true)
...