JavaFX FXML 教程中的错误

Question

我已按照本 (https://blogs.oracle.com/jmxetc/entry/connecting_scenebuilder_edited_fxml_to) 教程中的每个步骤进行操作，但在控制器中一直收到有关此部分的错误 class:

    myButton.setOnAction(new EventHandler<ActionEvent>() {

        @Override
        public void handle(ActionEvent event) {
            System.out.println("That was easy, wasn't it?");
        }
    });

我能想到的唯一区别是它是为 FX 2.0 而不是 8.0 编写的？

Exception in Application start method
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication5(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.Error: Unresolved compilation problems: 
    The method setOnAction(EventHandler<ActionEvent>) in the type ButtonBase is not applicable for the arguments (new EventHandler<ActionEvent>(){})
    EventHandler cannot be resolved to a type
    The method handle(ActionEvent) of type new EventHandler<ActionEvent>(){} must override or implement a supertype method

    at simple.SimpleController.initialize(SimpleController.java:24)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
    at simple.Main.start(Main.java:26)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication12(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait5(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null3(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater4(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception running application simple.Main

如果您需要查看 classes 和 FXML 文件（dw，它们很短）请告诉我

谢谢！

PS- 如果我需要澄清您的回答，请耐心等待，因为作为 Java 新手，我经常感到困惑！

编辑 1：

package simple;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class SimpleController
    implements Initializable {

    @FXML //  fx:id="myButton"
    private Button myButton; // Value injected by FXMLLoader


    @Override // This method is called by the FXMLLoader when initialization is complete
    public void initialize(URL fxmlFileLocation, ResourceBundle resources) {
        assert myButton != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";

        // initialize your logic here: all @FXML variables will have been injected
        myButton.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event) {
                System.out.println("That was easy, wasn't it?");
            }
        });
    }

}

Answer 1

您缺少 EventHandler 的导入，并且 ActionEvent 的导入错误。（此外，您出于某种原因导入了 ActionListener，尽管您从未使用过它。）

你的导入应该是

import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;

JavaFX FXML 教程中的错误

Error in JavaFX FXML tutorial

eclipse

oracle

model-view-controller

javafx

fxml