在MVP中实例化视图的责任

Question

在使用MVP架构设计应用程序时,我提出了关于实例化视图的问题.在我的情况下,演示者必须与视图完全分离,以便轻松更改UI工具包.只要只有一个视图,一切都很清楚.当需要动态创建视图时,我的问题出现了.例如,当单击新按钮时,弹出窗口要求用户填写一些数据.我有两个解决方案,但我对其他人感到好奇.我在下面给出了我的方法的示例代码.

1. 让我们的父视图实例化对话框视图并将其返回到父对象,其中对话框演示者也实例化.我不喜欢具体视图必须实例化另一个视图的想法.我有一种感觉,实例化不是视图的责任.

   public interface View {
     public void setPresenter(Presenter presenter);
     public void showView();
   }
   
   public interface NewDialogView implements View {
     /* ommited ordinary getters/setters for view */
   }
   
   public interface MainWindowView implements View {
   
     /* ommited ordinary getters/setters for view */
   
     public NewDialogView createNewDialog();
   }
   
   public interface Presenter {
     public View getView();
   }
   
   public class NewDialogPresenter implements Presenter {
   
     protected NewDialogView view;
   
     public MainWindow(NewDialogView view) {
         this.view = view;
         this.view.setPresenter(this);
     }
   
     public View getView() {
       return view;
     }
   }
   
   public class MainWindowPresenter implements Presenter {
   
     protected MainWindowView view;
   
     public MainWindow(MainWindowView view) {
         this.view = view;
         this.view.setPresenter(this);
     }
   
     public void newButtonClicked() {
       NewDialogView newDialogView = view.createNewDialog(); // too much responsibility?
       NewDialogPresenter newDialogPresenter = new NewDialogPresenter(newDialogView);
       newDialogView.showView();
   
       /* then let's NewDialogPresenter deal with user input */
     }
   
     public View getView() {
       return view;
     }
   }
   

2. 将工厂注入演示者.该工厂负责即时查看.将父视图传递给对话框视图存在一些问题(通常GUI框架需要它).还有相当多的设置.

   // Just presenter approach differs and there is no create method in view interface.
   
   public interface MainWindowView implements View {
     /* ommited ordinary getters/setters for view */
   }
   
   public class MainWindowPresenter implements Presenter {
   
     protected MainWindowView view;
     protected NewDialogViewFactory newDialogViewFactory;
   
     public MainWindow(MainWindowView view) {
         this.view = view;
         this.view.setPresenter(this);
     }
   
     public void newButtonClicked() {
       NewDialogView newDialogView = newDialogViewFactory.createNewDialog(view); // should pass a parent view here or not?
       NewDialogPresenter newDialogPresenter = new NewDialogPresenter(newDialogView);
       newDialogView.showView();
       // then let's NewDialogPresenter deal with user input
     }
   
     public View getView() {
       return view;
     }
   
     public void setNewDialogViewFactory(NewDialogViewFactory newDialogViewFactory) {
       this.newDialogViewFactory = newDialogViewFactory;
     }
   }
   

您对实例化新演示者和视图的责任有何看法？我正在寻找其他人方法的实际例子.谢谢你的建议.

Answer 1

就我而言，我实际上从不创建视图（包括对话框）。我假设任何时候都不会出现多个对话框，因此我使用GIN来实例化对话框并将其注入到演示器中。然后，演示者只需更改对话框上的属性（包括处理程序）并显示它。这使我能够使用 GIN 在一个地方管理所有视图（和演示者）的创建。