无法在JavaFX中加载控制器

现在我正在做一个关于JavaFX的文件管理软件的项目，但是出现了很多错误

我有一些课：

文件Main.java

package QLF;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

    public class Main extends Application
    {

    @Override
    public void start(Stage primaryStage) throws Exception
    {
        Parent root =    FXMLLoader.load(getClass().getResource("LogIn.fxml"));

        Scene scene = new Scene(root);
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(scene);
        primaryStage.show();
    }


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

package QLF; 
import javafx.scene.control.*; 
import javafx.fxml.*; 
import javafx.event.*;
import java.net.URL; 
import java.util.ResourceBundle;

    public class Controller implements Initializable
    {
    @FXML
    private Button btnSignIn;

    @FXML
    private Button btnQuit;

    @FXML
    private TextField txtUserName;

    @FXML
    private PasswordField txtPassword;

    @FXML
    private Label lblUStatus;

    @FXML
    private Label lblPStatus;

    @FXML
    private void handleEvent(ActionEvent event)
    {
        if(event.getSource() == btnSignIn)
        {
            //check 'null'
            if(txtUserName.getText().equals(null))
            {
                lblUStatus.setVisible(true);
                lblUStatus.setText("You have to enter your Username or your Email");
            }

            else if(txtPassword.getText().equals(null))
            {
                lblPStatus.setVisible(true);
                lblPStatus.setText("You have to enter your Password");
            }
        }

        if(event.getSource() == btnQuit)
        {

        }
    }
    @Override
    public void initialize(URL location, ResourceBundle resources)
    {

    }   
}

文件Controller.java

package QLF;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

    public class Main extends Application
    {

    @Override
    public void start(Stage primaryStage) throws Exception
    {
        Parent root =    FXMLLoader.load(getClass().getResource("LogIn.fxml"));

        Scene scene = new Scene(root);
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(scene);
        primaryStage.show();
    }


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

package QLF; 
import javafx.scene.control.*; 
import javafx.fxml.*; 
import javafx.event.*;
import java.net.URL; 
import java.util.ResourceBundle;

    public class Controller implements Initializable
    {
    @FXML
    private Button btnSignIn;

    @FXML
    private Button btnQuit;

    @FXML
    private TextField txtUserName;

    @FXML
    private PasswordField txtPassword;

    @FXML
    private Label lblUStatus;

    @FXML
    private Label lblPStatus;

    @FXML
    private void handleEvent(ActionEvent event)
    {
        if(event.getSource() == btnSignIn)
        {
            //check 'null'
            if(txtUserName.getText().equals(null))
            {
                lblUStatus.setVisible(true);
                lblUStatus.setText("You have to enter your Username or your Email");
            }

            else if(txtPassword.getText().equals(null))
            {
                lblPStatus.setVisible(true);
                lblPStatus.setText("You have to enter your Password");
            }
        }

        if(event.getSource() == btnQuit)
        {

        }
    }
    @Override
    public void initialize(URL location, ResourceBundle resources)
    {

    }   
}

文件LogIn.fxml

错误

 Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: argument type mismatch
    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:498)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3470)
    at javafx.scene.Scene$ClickGenerator.access$8100(Scene.java:3398)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3766)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:748)

---

onMouseClicked

事件导致

MouseEvent

s非

ActionEvent

s。由于

MouseEvent

无法强制转换为

ActionEvent

，

handleEvent

无法处理

MouseEvent

s

请改用

onAction

事件处理程序：

。。。
...

现在我解决了这个问题。不用再回答了