c# - WinForms MVP 是否有另一种方法可以将数据绑定(bind)到 View 而无需 Presenter 访问 View 控件？

Question

我有一个 WinForms 应用程序设置来使用模型 View 演示器。为了避免 View 了解模型，我正在考虑让演示者使用 View 的实例来访问 View 文本框，并将它们数据绑定(bind)到演示者也具有的模型的实例。采用这种方法有什么问题？

我考虑过的另一个选择是让 View 拥有模型的实例。模型属性将具有 INotifyPropertyChanged 设置。在这种情况下，我可以让 View 将数据绑定(bind)设置到它具有的文本框和它也具有的模型实例。这样做有什么问题吗？

我考虑过的另一个选项是将模型属性复制到演示器中并使用 INotifyPropertyChanged 进行设置。然后，当 View 具有演示器的实例时，我可以让 View 将其文本框数据绑定(bind)到演示器中的匹配属性。通过此设置，当演示者进行数据访问调用时，它将为其本身的属性设置值，这将自动更新与演示者属性数据绑定(bind)的 View 文本框。

如果我不使用数据绑定(bind)，我只需在 View 中添加 getter 和 setter，以便演示者访问 View 文本框值。演示者将使用 View getter 和 setter 来执行数据访问调用。在从数据访问调用接收数据后，演示者还将使用 setter 来设置 View 文本框值。

我正在考虑的这些选项基于我看过的文章，但也许​​还有另一种方法可以在我没有见过的 WinForms MVP 实现中管理数据。请提供反馈，说明推荐的方法用于管理从 View 到演示者或模型的来回数据，或者可能需要在此处添加另一层(例如某种服务)？ 提前致谢。

==================================== 更新 04/10/2018

我能够设置我的应用程序，以便 View 和模型没有对演示者的引用，同时允许演示者引用 View 和模型。当我发现如何从 Presenter 中绑定(bind)到 View 控件所需的数据时，这成为可能。这不需要让 Presenter 直接访问属于 View 的可视控件。

DepartmentPresenter 字段:

 public class DepartmentPresenter : IDepartmentPresenter
 {
  private IDepartmentView departmentView;
  private IDepartmentModel departmentModel;
  private IDepartmentRepository departmentRepository;
  ....
}

这是演示者的实例化:

  void OnDisplayDepartmenSelectedRaised(object sender, DisplayDepartmentSelectedEventArgs e)
  {
   //Get current selected data row from Presenters BindingSource which used by the View to bind 
   //to its DataGridView. The view only knew it wasw a BindingSource and never had to know it
   //was a collectino of DepartmentModel Data Transfer Objects (DTOs) 
   selectedDepartmentModel = (DepartmentModel)departmentModelBindingSource.Current;

  DepartmentPresenter aDepartmentPresenter = new DepartmentPresenter(departmentView,
                                                                     departmentRepository,
                                                                     selectedDepartmentModel.DepartmentId);
  }

演示者构造函数:

  public DepartmentPresenter(IDepartmentView departmentView,
                             IDepartmentRepository departmentRepository,
                             int selectedDepartmentId)
  {
   this.departmentRepository = departmentRepository;
   departmentModel = departmentRepository.GetById(selectedDepartmentId);
   this.departmentView = departmentView;

   //Subscribe to View's save request from save button so Presenter can perform work to be done on a save
   this.departmentView.SaveDepartmentRaised += new EventHandler(OnSaveDepartmentRaised);

   //Create bindings for data the View will use on its textBoxes
   Binding departmentNameBinding = new Binding("Text", DepartmentModel, "DepartmentName", true, DataSourceUpdateMode.OnPropertyChanged);
   Binding cityLocationBinding = new Binding("Text", departmentModel, "CityLocation", true, DataSourceUpdateMode.OnPropertyChanged);
   Binding stateLocationBinding = new Binding("Text", departmentModel, "StateLocation", true, DataSourceUpdateMode.OnPropertyChanged);

   //Store bindings into a dictionary for the View to access for its textBoxes
   Dictionary<string, Binding> bindingDictionary = new Dictionary<string, Binding>();
   bindingDictionary.Add("DepartmentName", departmentNameBinding);
   bindingDictionary.Add("CityLocation", cityLocationBinding);
   bindingDictionary.Add("StateLocation", stateLocationBinding);

   //Use passed in reference to View to tell view to bind its textBoxes using the passed in Dictionary of bindings
   this.departmentView.BindDisplayData(bindingDictionary);

   this.departmentView.ShowView();
  }

以下是 View 如何绑定(bind)到其文本框控件以响应演示者告诉它这样做的方式:

  public void BindDisplayData(Dictionary<string, Binding> bindingDictinary)
  {
   textBoxName.DataBindings.Add(bindingDictinary["DepartmentName"]);
   textBoxCity.DataBindings.Add(bindingDictinary["CityLocation"]);
   textBoxState.DataBindings.Add(bindingDictinary["StateLocation"]);
  }

这是 View 的接口(interface)定义:

 public interface IDepartmentView
 {
  event EventHandler SaveDepartmentRaised;
  void ShowView();
  void BindDisplayData(Dictionary<string, Binding> bindingDictinary);
 }

希望这能帮助那些尝试从模型 View 演示器项目中的演示器绑定(bind)到 View 的人，同时尝试避免使 View 具有演示器的实例。

Answer 1

创建一个接口(interface)，您的 View 将实现该接口(interface)并可以引用演示者:

public interface IView<T> where T : class
{
    T Presenter { get; set; }
}

以及 View :

public class TheView : Form, IView<ThePresenter>
{
    public ThePresenter Presenter { get; set; }
}

现在您可以注入(inject)演示者，并且 View 可以使用“Presenter”属性来创建绑定(bind)。