Question

我无法理解如何在JavaFX中应用mvc模式。

这是我对以下代码的疑问，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comboBox。

请注意，方法getModelItems()是私有的。

b）我的视图中将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)，并且要传递的参数是viewA中comboBox上的选定值。我该如何实现？

非常感谢您的帮助！

下面是说明中引用的代码。

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);

    }
}

加载程序：

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

您将委托添加到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(...) { ... }
    ...
}

您可以根据想要通过ViewA管理的数量来随意选择。

如何将事件处理程序附加到MVC中的控制器。 JavaFX

1 个答案: