从现有MVC创建

Question

所以我有我的模型，我想从一个下拉列表中选择一个新的植物来创建一个新的植物，除了科学名称之外，它的属性与旧植物相同。我创建了一个函数，它将采用新的植物名称和旧的植物，并创建一个新的植物，具有旧的特性。我想知道我应该做些什么，在我的控制器和视图中创建这个新植物，以便从现有的植物中创建这个新植物。

这是我的模型

public class ExistingPlant
{

    public string selectedPlant { get; set; }
    public Dictionary<Guid,string> plantList { get; set; }
}

这是我的控制器代码

public ActionResult CreateFrom()
    {
        ExistingPlant existing = new ExistingPlant();

        Dictionary<Guid, string> plants = new Dictionary<Guid, string>();

        foreach(var item in context.Plants){

            plants.Add(item.PlantId , item.ScientificName);
             }

        existing.plantList = plants;
        existing.selectedPlant = "Value";

        var plant = context.Plants.Where(d => d.ScientificName == existing.selectedPlant);
        string temp = existing.selectedPlant;
        Plant p = (Plant) plant;
        CopyExisting(p,temp);

        return View(existing);
    }

我的视图代码是：

@using (Html.BeginForm())
{
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)
<fieldset id="field">
    <div>
        <label> Scientific Name:</label>
    </div>

    <div class="editor-field">
        @Html.EditorFor(m => m.selectedPlant)
        @Html.ValidationMessageFor(m =>m.selectedPlant)
    </div>

    <p>
        <input type="submit" value="Create" />
    </p>

</fieldset>
@Html.DropDownListFor(
    m => m.selectedPlant,
    new SelectList(Model.plantList, "Key", "Value")
)

}

Answer 1

您需要在视图模型中为新名称提供一个属性，当您提交表单时，获取所选的植物，克隆它，根据视图模型更新科学名称并保存它。

将视图模型更改为

public class CopyPlantVM
{
  [Display(Name = "Existing Plant")]
  [Required(ErrorMessage = "Please select an existing plant")]
  public Guid ExistingPlant { get; set; }
  public SelectList ExistingPlantList { get; set; }
  [Display(Name = "New scientific name")]
  [Required(ErrorMessage = "Please enter new scientific name")]
  public string Name { get; set; }
}

的观点是

@model CopyPlantVM
@using (Html.BeginForm())
{
  @Html.LabelFor(m => m.ExistingPlant)
  @Html.DropDownListFor(m => m.ExistingPlant, Model.ExistingPlantList, "Please select")
  @Html.ValidationMessageFor(m => m.ExistingPlant)

  @Html.LabelFor(m => m.Name)
  @Html.TextBoxFor(m => m.Name)
  @Html.ValidationMessageFor(m => m.Name)

  <input type="submit" value="Create" />
}

以及控制器的方法

public ActionResult CreateFrom()
{
  CopyPlantVM model = new CopyPlantVM();
  ConfigureViewModel(model);
  return View(model);
}

[HttpPost]
public ActionResult CreateFrom(CopyPlantVM model)
{
  if (!ModelState.IsValid)
  {
    ConfigureViewModel(model);
    return View(model);
  }
  // Get the selected plant
  Plant existingPlant = db.Plants.Where(p => p.PlantID = model.ExistingPlant).FirstOrDefault();
  // Create a new plant based on existing plant but with new name
  Plant newPlant = new Plant
  {
    ScientificName = model.Name,
    // set other properties based on existing plant
  };
  db.Plants.Add(newPlant);
  db.SaveChanges();
  return RedirectToAction(...);
}

private void ConfigureViewModel(CopyPlantVM model)
{
  model.ExistingPlantList = new SelectList(db.Plants, "PlantId", "ScientificName");
}