c# - 如何在不发出其他请求的情况下在编辑操作中使用 ViewModel？

Question

我需要关于这个特殊案例的具体答案或解决方案，我有 EditVehicleViewModel 像这样传递给 Edit Vehicle Controller Action

public async Task<ActionResult> Edit(EditVehicleViewModel vehiclViewModel)
{
    if (ModelState.IsValid)
    {

         // I NEED TO MAP THE VIEW_MODEL TO THE MODEL HERE 

        db.Entry(vehicleModel).State = EntityState.Modified;
        await db.SaveChangesAsync();
        return RedirectToAction("Index");
    }

    return View(vehiclViewModel);
}

我需要根据对 ViewModel 所做的更改来更新模型，而不是请求获取已更改的 Vehicle 和 SaveChanges() ，同时仍然使用这行代码如果可能的话

db.Entry(vehiclViewModel).State = EntityState.Modified;

编辑这是我的模型和 ViewModel

ViewModel

public class EditVehicleViewModel
{
    [Required]
    public string LicenceNumber { get; set; }

    public int? Year { get; set; }

    public string Color { get; set; }

    [DataType(DataType.Upload)]
    public HttpPostedFileBase ImageUpload { get; set; }

    public string VINNumber { get; set; }
}

模型

public class Vehicle
{
    public int ID { get; set; }

    [Required]
    public string LicenceNumber { get; set; }

    [Required]
    public Nullable<DateTime> Year { get; set; }

    [Required]
    public string Color { get; set; }

    [DataType(DataType.ImageUrl)]
    public string ImageUrl { get; set; }

    [Required]
    public string VINNumber { get; set; }
 }

Answer 1

首先，您必须从 nuget 安装以下任一软件包，

PM> 安装包TinyMapper

或

PM> 安装包 AutoMapper

然后添加你的代码，如果使用了tinymapper

TinyMapper.Bind<Vehicle, EditVehicleViewModel>();
Vehicle vehicleModel = TinyMapper.Map<EditVehicleViewModel>(vehiclViewModel);
db.Entry(vehicleModel).State = EntityState.Modified;

或

如果使用自动映射器，

Mapper.CreateMap<Vehicle , EditVehicleViewModel>();
Vehicle vehicleModel = Mapper.Map<EditVehicleViewModel>(vehiclViewModel);
db.Entry(vehicleModel).State = EntityState.Modified;