Java FX将函数作为参数发送到方法

更新2019.05.14美国东部时间下午4:54-好的-下面是说明我的问题的代码-我可能花了太长的时间才得到这个，而且可能太长了，但我还是Java新手。无论如何-它可以工作，打开表单，但无法让第二个按钮查看并对“事件”作出反应。我想我现在正在“提升”事件，好吧-至少它在事件中击中了代码。但是，它仍然在运行类代码，而不是通过setOnFormStateChange传入的“自定义”代码？？？？我不知道怎么了

所有导入内容

import java.util.ArrayList;
import java.util.Date;
import javafx.application.Application;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.event.EventType;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

MyApp.java

public class MyApp extends Application {

    public static void main(String[] args) {
        launch(args); // this method will hang here until main form is closed!
    }

    @Override
    public void start(Stage stage) throws Exception {
        Form myForm = new Form();
        myForm.ShowForm();
    }

}

class Form {

    private boolean modified;
    private ArrayList<FormStateChangeListener> registry = new ArrayList<>();

    public void setModified(boolean m) {
        modified = m;
        this.throwStateChange(m);
    }

    public void throwStateChange(boolean m) {
        for (FormStateChangeListener o : registry) {
          //  o.onFormStateChange(m);         
            FormStateChangeEvent.fireEvent(o,m);
        }
    }

    public void ShowForm() {

        Label lbl = new Label("NORMAL STATE");
        lbl.setLayoutX(50);
        lbl.setLayoutY(20);

        Btn myBtn1 = new Btn(this);
        myBtn1.setLayoutX(100);
        myBtn1.setLayoutY(100);
        myBtn1.setPrefWidth(200);

        myBtn1.setText("Press To Change State");
        myBtn1.setOnAction(e -> {
            lbl.setText("CHANGED STATE:" + new Date().toString());
            this.setModified(true);
        });

        Btn myBtn2 = new Btn(this);
        myBtn2.setLayoutX(100);
        myBtn2.setLayoutY(200);
        myBtn2.setPrefWidth(200);
        myBtn2.setText("And This Should React");

        myBtn2.setOnFormStateChange(e -> {
            myBtn2.setText("I REACTED!");
        });


        Stage stage = new Stage();
        AnchorPane root = new AnchorPane();
        Scene scene = new Scene(root, 430, 400);
       // root.getChildren().add(lbl);
       // root.getChildren().add(myBtn1);
       // root.getChildren().add(myBtn2);
        root.getChildren().addAll(lbl,myBtn1,myBtn2);
        stage.setScene(scene);
        stage.showAndWait();
    }

    void registerForEvent(FormStateChangeListener t) {
        registry.add(t);

    }

}

interface FormStateChangeListener {
    public void onFormStateChange(boolean mod);
}

enum FormState {
    NORMAL, MODIFIED, NEW
}

class Btn extends Button implements FormStateChangeListener {

    private final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChange
            = new SimpleObjectProperty<EventHandler<? super FormStateChangeEvent>>(this, "onFormStateChange") {

        @Override
        protected void invalidated() {
            setEventHandler(FormStateChangeEvent.FORM_STATE_CHANGE, get());
        }
    };

    public Btn(Form f) { // constructor
        f.registerForEvent(this); // register for the event
    }

    public final void setOnFormStateChange(EventHandler<? super FormStateChangeEvent> handler) {
        onFormStateChange.set(handler);
    }

    public final EventHandler<? super FormStateChangeEvent> getOnFormStateChange() {
        return onFormStateChange.get();
    }

    public final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChangeProperty() {
        return onFormStateChange;
    }

    public void onFormStateChange(boolean mod) {
        //in reality nothing would be here, but is just for testing
       System.out.println("Code from class.");
    }
;

}

class FormStateChangeEvent extends Event {

    public static final EventType<FormStateChangeEvent> ANY = new EventType<>(Event.ANY, "MY_EVENT");
    public static final EventType<FormStateChangeEvent> FORM_STATE_CHANGE = new EventType<>(ANY, "FORM_STATE_CHANGE");

    static void fireEvent(FormStateChangeListener o, boolean mod) {
        //throw new UnsupportedOperationException("Not supported yet."); 
        o.onFormStateChange(mod);
    }

    public FormStateChangeEvent(EventType<? extends FormStateChangeEvent> eventType) {
        super(eventType);
    }
}

Form.java

public class MyApp extends Application {

    public static void main(String[] args) {
        launch(args); // this method will hang here until main form is closed!
    }

    @Override
    public void start(Stage stage) throws Exception {
        Form myForm = new Form();
        myForm.ShowForm();
    }

}

class Form {

    private boolean modified;
    private ArrayList<FormStateChangeListener> registry = new ArrayList<>();

    public void setModified(boolean m) {
        modified = m;
        this.throwStateChange(m);
    }

    public void throwStateChange(boolean m) {
        for (FormStateChangeListener o : registry) {
          //  o.onFormStateChange(m);         
            FormStateChangeEvent.fireEvent(o,m);
        }
    }

    public void ShowForm() {

        Label lbl = new Label("NORMAL STATE");
        lbl.setLayoutX(50);
        lbl.setLayoutY(20);

        Btn myBtn1 = new Btn(this);
        myBtn1.setLayoutX(100);
        myBtn1.setLayoutY(100);
        myBtn1.setPrefWidth(200);

        myBtn1.setText("Press To Change State");
        myBtn1.setOnAction(e -> {
            lbl.setText("CHANGED STATE:" + new Date().toString());
            this.setModified(true);
        });

        Btn myBtn2 = new Btn(this);
        myBtn2.setLayoutX(100);
        myBtn2.setLayoutY(200);
        myBtn2.setPrefWidth(200);
        myBtn2.setText("And This Should React");

        myBtn2.setOnFormStateChange(e -> {
            myBtn2.setText("I REACTED!");
        });


        Stage stage = new Stage();
        AnchorPane root = new AnchorPane();
        Scene scene = new Scene(root, 430, 400);
       // root.getChildren().add(lbl);
       // root.getChildren().add(myBtn1);
       // root.getChildren().add(myBtn2);
        root.getChildren().addAll(lbl,myBtn1,myBtn2);
        stage.setScene(scene);
        stage.showAndWait();
    }

    void registerForEvent(FormStateChangeListener t) {
        registry.add(t);

    }

}

interface FormStateChangeListener {
    public void onFormStateChange(boolean mod);
}

enum FormState {
    NORMAL, MODIFIED, NEW
}

class Btn extends Button implements FormStateChangeListener {

    private final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChange
            = new SimpleObjectProperty<EventHandler<? super FormStateChangeEvent>>(this, "onFormStateChange") {

        @Override
        protected void invalidated() {
            setEventHandler(FormStateChangeEvent.FORM_STATE_CHANGE, get());
        }
    };

    public Btn(Form f) { // constructor
        f.registerForEvent(this); // register for the event
    }

    public final void setOnFormStateChange(EventHandler<? super FormStateChangeEvent> handler) {
        onFormStateChange.set(handler);
    }

    public final EventHandler<? super FormStateChangeEvent> getOnFormStateChange() {
        return onFormStateChange.get();
    }

    public final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChangeProperty() {
        return onFormStateChange;
    }

    public void onFormStateChange(boolean mod) {
        //in reality nothing would be here, but is just for testing
       System.out.println("Code from class.");
    }
;

}

class FormStateChangeEvent extends Event {

    public static final EventType<FormStateChangeEvent> ANY = new EventType<>(Event.ANY, "MY_EVENT");
    public static final EventType<FormStateChangeEvent> FORM_STATE_CHANGE = new EventType<>(ANY, "FORM_STATE_CHANGE");

    static void fireEvent(FormStateChangeListener o, boolean mod) {
        //throw new UnsupportedOperationException("Not supported yet."); 
        o.onFormStateChange(mod);
    }

    public FormStateChangeEvent(EventType<? extends FormStateChangeEvent> eventType) {
        super(eventType);
    }
}

FormState.java

public class MyApp extends Application {

    public static void main(String[] args) {
        launch(args); // this method will hang here until main form is closed!
    }

    @Override
    public void start(Stage stage) throws Exception {
        Form myForm = new Form();
        myForm.ShowForm();
    }

}

class Form {

    private boolean modified;
    private ArrayList<FormStateChangeListener> registry = new ArrayList<>();

    public void setModified(boolean m) {
        modified = m;
        this.throwStateChange(m);
    }

    public void throwStateChange(boolean m) {
        for (FormStateChangeListener o : registry) {
          //  o.onFormStateChange(m);         
            FormStateChangeEvent.fireEvent(o,m);
        }
    }

    public void ShowForm() {

        Label lbl = new Label("NORMAL STATE");
        lbl.setLayoutX(50);
        lbl.setLayoutY(20);

        Btn myBtn1 = new Btn(this);
        myBtn1.setLayoutX(100);
        myBtn1.setLayoutY(100);
        myBtn1.setPrefWidth(200);

        myBtn1.setText("Press To Change State");
        myBtn1.setOnAction(e -> {
            lbl.setText("CHANGED STATE:" + new Date().toString());
            this.setModified(true);
        });

        Btn myBtn2 = new Btn(this);
        myBtn2.setLayoutX(100);
        myBtn2.setLayoutY(200);
        myBtn2.setPrefWidth(200);
        myBtn2.setText("And This Should React");

        myBtn2.setOnFormStateChange(e -> {
            myBtn2.setText("I REACTED!");
        });


        Stage stage = new Stage();
        AnchorPane root = new AnchorPane();
        Scene scene = new Scene(root, 430, 400);
       // root.getChildren().add(lbl);
       // root.getChildren().add(myBtn1);
       // root.getChildren().add(myBtn2);
        root.getChildren().addAll(lbl,myBtn1,myBtn2);
        stage.setScene(scene);
        stage.showAndWait();
    }

    void registerForEvent(FormStateChangeListener t) {
        registry.add(t);

    }

}

interface FormStateChangeListener {
    public void onFormStateChange(boolean mod);
}

enum FormState {
    NORMAL, MODIFIED, NEW
}

class Btn extends Button implements FormStateChangeListener {

    private final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChange
            = new SimpleObjectProperty<EventHandler<? super FormStateChangeEvent>>(this, "onFormStateChange") {

        @Override
        protected void invalidated() {
            setEventHandler(FormStateChangeEvent.FORM_STATE_CHANGE, get());
        }
    };

    public Btn(Form f) { // constructor
        f.registerForEvent(this); // register for the event
    }

    public final void setOnFormStateChange(EventHandler<? super FormStateChangeEvent> handler) {
        onFormStateChange.set(handler);
    }

    public final EventHandler<? super FormStateChangeEvent> getOnFormStateChange() {
        return onFormStateChange.get();
    }

    public final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChangeProperty() {
        return onFormStateChange;
    }

    public void onFormStateChange(boolean mod) {
        //in reality nothing would be here, but is just for testing
       System.out.println("Code from class.");
    }
;

}

class FormStateChangeEvent extends Event {

    public static final EventType<FormStateChangeEvent> ANY = new EventType<>(Event.ANY, "MY_EVENT");
    public static final EventType<FormStateChangeEvent> FORM_STATE_CHANGE = new EventType<>(ANY, "FORM_STATE_CHANGE");

    static void fireEvent(FormStateChangeListener o, boolean mod) {
        //throw new UnsupportedOperationException("Not supported yet."); 
        o.onFormStateChange(mod);
    }

    public FormStateChangeEvent(EventType<? extends FormStateChangeEvent> eventType) {
        super(eventType);
    }
}

Btn.java

public class MyApp extends Application {

    public static void main(String[] args) {
        launch(args); // this method will hang here until main form is closed!
    }

    @Override
    public void start(Stage stage) throws Exception {
        Form myForm = new Form();
        myForm.ShowForm();
    }

}

class Form {

    private boolean modified;
    private ArrayList<FormStateChangeListener> registry = new ArrayList<>();

    public void setModified(boolean m) {
        modified = m;
        this.throwStateChange(m);
    }

    public void throwStateChange(boolean m) {
        for (FormStateChangeListener o : registry) {
          //  o.onFormStateChange(m);         
            FormStateChangeEvent.fireEvent(o,m);
        }
    }

    public void ShowForm() {

        Label lbl = new Label("NORMAL STATE");
        lbl.setLayoutX(50);
        lbl.setLayoutY(20);

        Btn myBtn1 = new Btn(this);
        myBtn1.setLayoutX(100);
        myBtn1.setLayoutY(100);
        myBtn1.setPrefWidth(200);

        myBtn1.setText("Press To Change State");
        myBtn1.setOnAction(e -> {
            lbl.setText("CHANGED STATE:" + new Date().toString());
            this.setModified(true);
        });

        Btn myBtn2 = new Btn(this);
        myBtn2.setLayoutX(100);
        myBtn2.setLayoutY(200);
        myBtn2.setPrefWidth(200);
        myBtn2.setText("And This Should React");

        myBtn2.setOnFormStateChange(e -> {
            myBtn2.setText("I REACTED!");
        });


        Stage stage = new Stage();
        AnchorPane root = new AnchorPane();
        Scene scene = new Scene(root, 430, 400);
       // root.getChildren().add(lbl);
       // root.getChildren().add(myBtn1);
       // root.getChildren().add(myBtn2);
        root.getChildren().addAll(lbl,myBtn1,myBtn2);
        stage.setScene(scene);
        stage.showAndWait();
    }

    void registerForEvent(FormStateChangeListener t) {
        registry.add(t);

    }

}

interface FormStateChangeListener {
    public void onFormStateChange(boolean mod);
}

enum FormState {
    NORMAL, MODIFIED, NEW
}

class Btn extends Button implements FormStateChangeListener {

    private final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChange
            = new SimpleObjectProperty<EventHandler<? super FormStateChangeEvent>>(this, "onFormStateChange") {

        @Override
        protected void invalidated() {
            setEventHandler(FormStateChangeEvent.FORM_STATE_CHANGE, get());
        }
    };

    public Btn(Form f) { // constructor
        f.registerForEvent(this); // register for the event
    }

    public final void setOnFormStateChange(EventHandler<? super FormStateChangeEvent> handler) {
        onFormStateChange.set(handler);
    }

    public final EventHandler<? super FormStateChangeEvent> getOnFormStateChange() {
        return onFormStateChange.get();
    }

    public final ObjectProperty<EventHandler<? super FormStateChangeEvent>> onFormStateChangeProperty() {
        return onFormStateChange;
    }

    public void onFormStateChange(boolean mod) {
        //in reality nothing would be here, but is just for testing
       System.out.println("Code from class.");
    }
;

}

class FormStateChangeEvent extends Event {

    public static final EventType<FormStateChangeEvent> ANY = new EventType<>(Event.ANY, "MY_EVENT");
    public static final EventType<FormStateChangeEvent> FORM_STATE_CHANGE = new EventType<>(ANY, "FORM_STATE_CHANGE");

    static void fireEvent(FormStateChangeListener o, boolean mod) {
        //throw new UnsupportedOperationException("Not supported yet."); 
        o.onFormStateChange(mod);
    }

    public FormStateChangeEvent(EventType<? extends FormStateChangeEvent> eventType) {
        super(eventType);
    }
}

类Btn扩展按钮实现FormStateChangeListener{
private final ObjectProperty方法，如
setOnMouseClicked
接受
javafx.event.EventHandler
，这是一个功能接口。换句话说，它有一个单一的抽象方法，这意味着它可以用作lambda表达式或方法引用的目标。如果您的目标是拥有自己的
事件
clas使用相应的
onXXX
属性，则您的
setOnXXX
方法必须像所有其他方法一样接受
EventHandler

但是，如果希望在正常事件分派期间调用
EventHandler
，仅设置属性是不够的。必须向事件分派器注册它，这可以通过受保护的
节点.setEventHandler（EventType，EventHandler）
方法完成

例如，假设以下是您的事件类：

import javafx.event.Event;
import javafx.event.EventType;

public class MyEvent extends Event {

    public static final EventType<MyEvent> ANY = new EventType<>(Event.ANY, "MY_EVENT");
    public static final EventType<MyEvent> AWESOME_THING = new EventType<>(ANY, "AWESOME_THING");

    public MyEvent(EventType<? extends MyEvent> eventType) {
        super(eventType);
    }

}

导入javafx.event.event；
导入javafx.event.EventType；
公共类MyEvent扩展事件{
public static final EventType ANY=新事件类型（Event.ANY，“我的事件”）；
公共静态最终事件类型AWESOME_THING=新事件类型（任意，“AWESOME_THING”）；
public MyEvent（EventTypeWhat阻止您使用普通setter？（或者如果您想提供它，请使用除此之外的属性？）如果发生应触发事件的事件，如果属性为非null，则调用事件处理程序的
handle
方法。可能会看到相关示例或函数参数。谢谢@Slaw！我觉得这是一个非常好的答案，可能是“正确的”，但由于在这方面太新了，我需要花点时间才能充分了解它，以便将它转换到我的特定情况。谢谢！好的-尝试将它复制到工作中，并使用它来帮助我了解它。遇到编译问题时，```=new SimpleObjectProperty（这是“onAwesomeThing”）``告诉我“无法推断SimpleObjectProperty的类型参数，然后是关于源代码8中不支持的内容-使用源代码9？-请在Java 8中建议，在实现通用匿名类时，不能使用菱形运算符。只需将其更改为
new SimpleObjectPropertyOk，谢谢-可以（编译）我能够在我的button实例上对一些愚蠢的测试代码执行btn.setOnMyEvent。但是，请原谅我的初学者，当我调用“btn.onMyEvent”时，它运行的是类代码，而不是我在实例时放入的“自定义”代码。也许我不理解“调用”的正确方式那个处理者？谢谢你的耐心和帮助！你能编辑你的问题提供一个答案吗？