如何在 MVC 中将事件处理程序附加到控制器 | JavaFX

Question

我无法理解如何使用 JavaFX 应用 mvc 模式。

以下是我对以下代码的问题，因为我需要遵循代码中给出的模式：

a) 如何将 ViewA 中存在的按钮的事件处理程序附加到 ControllerA 中的代码（特别是 attachEventHandlers() 方法）。例如，我希望我的按钮使用来自控制器的getModelItems() 方法的结果填充 ViewA 中的组合框。

注意getModelItems() 方法是私有的。

b) 我的视图中有多个按钮和事件处理程序。我将如何将它们中的每一个唯一地绑定到控制器？

c) 我想在控制器中的模型上调用setName(String name)，我要传递的参数是viewA 中comboBox 上的选定值。我怎样才能做到这一点？

非常感谢您的帮助！

下面是描述中提到的代码。

控制器：

import model.ModelA;
import view.ViewA;
public class ControllerA {

    private ViewA view;

    private ModelA model;

    public ControllerA(ViewA view, ModelA model) {
        //initialise model and view fields
        this.model = model;
        this.view = view;

        //populate combobox in ViewB, e.g. if viewB represented your ViewB you could invoke the line below
        //viewB.populateComboBoxWithCourses(setupAndRetrieveCourses());

        this.attachEventHandlers(); 

    }

    private void attachEventHandlers() {
    }


    private String[] getModelItems() {

        String[] it = new String[2];
        it[0] = "0";
        it[1] = "1";

        return it;
    }

}

型号：

public class ModelA {

    private String name;


    public Name() {
        name = "";
    }



    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Name = " + name;
    }

}

查看：

import javafx.scene.layout.BorderPane;

//You may change this class to extend another type if you wish
public class ViewA extends BorderPane {
    public BorderPane bp;

    public ViewA(){
        this.bp = new BorderPane();
        ComboBox comboBox = new ComboBox();
        Button button1 = new Button("Populate");
        bp.setTop(button1);
        bp.setBottom(comboBox);

    }
}

加载器：

public class ApplicationLoader extends Application {

    private ViewA view;

    @Override
    public void init() {
        //create model and view and pass their references to the controller
        ModelA model = new ModelA();
        view = new ViewA();
        new ControllerA(view, model);   
    }

    @Override
    public void start(Stage stage) throws Exception {
        //whilst you can set a min width and height (example shown below) for the stage window,
        //you should not set a max width or height and the application should
        //be able to be maximised to fill the screen and ideally behave sensibly when resized
        stage.setMinWidth(530); 
        stage.setMinHeight(500);


        stage.setTitle("Final Year Module Chooser Tool");
        stage.setScene(new Scene(view));
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

}

Answer 1

您将代理添加到您的 ViewA 以允许访问：

public class ViewA extends BorderPane {
    ComboBox comboBox;
    Button button1;

    public ViewA(){
        comboBox = new ComboBox();
        button1 = new Button("Populate");
        setTop(button1);
        setBottom(comboBox);
    }

    // Add delegates for all functionality you want to make available through ViewA
    public ObservableList<String> getItems() { return comboBox.getItems(); }
    public void setOnButton1Action(...) { ... }
    public void setOnButton2Action(...) { ... }
    ...
}

您可以根据自己想通过 ViewA 管理多少来选择宽泛或窄。