Question

我有一个用javafx创建的工作计算器程序。但是，为了改进我的程序，我决定也包括键输出来输入数字。为此我必须调用我的Controller类的实例来从主类传递参数，在那里我将keyevent记录到我的FXMLController。但是在我修改代码之后，它没有编译在我的主类中显示异常。它给出 AnchorPane不能转换为javafx.fxml.FXMLLoader

以下是以前的工作代码：

public class Mycalc extends Application {

@Override
public void start(Stage stage) throws Exception {
    stage.initStyle(StageStyle.TRANSPARENT);

    FXMLLoader loader= FXMLLoader.load(getClass().getResource("calc1.fxml"));
    Parent root = loader.load();


    Scene scene = new Scene(root,Color.TRANSPARENT);

    stage.setScene(scene);
    stage.show();
    calc1Controller controller= loader.getController();
    scene.setOnKeyPressed(new EventHandler<KeyEvent>() 
    {
        @Override
        public void handle(KeyEvent keyEvent) 
        {

            switch (keyEvent.getCode()) 
            {
                case DIGIT1:
                    controller.handleDigit("1");
                    break ;
                case DIGIT2:
                    controller.handleDigit("2");
                    break ;
                case DIGIT3:
                    controller.handleDigit("3");
                    break ;
                case DIGIT4:
                    controller.handleDigit("4");
                    break ;
                case DIGIT5:
                    controller.handleDigit("5");
                    break ;
                case DIGIT6:
                    controller.handleDigit("6");
                    break ;
                case DIGIT7:
                    controller.handleDigit("7");
                    break ;
                case DIGIT8:
                    controller.handleDigit("8");
                    break ;
                case DIGIT9:
                    controller.handleDigit("9");
                    break ;
                case ADD:
                    controller.handleOperatorkey("+");
                    break ;
                case SUBTRACT:
                    controller.handleOperatorkey("-");
                    break ;
                case MULTIPLY:
                    controller.handleOperatorkey("*");
                    break ;
                case DIVIDE:
                    controller.handleOperatorkey("/");
                    break ;
                case EQUALS:
                    controller.handleEqualKey();
                    break ;
            }
        }   
    });
}

这是当前代码（有错误）：

   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:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:367)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:305)
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:483)
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:894)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:56)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:158)
at java.lang.Thread.run(Thread.java:745)
    Caused by: java.lang.ClassCastException: javafx.scene.layout.AnchorPane cannot be cast to javafx.fxml.FXMLLoader
at mycalc.Mycalc.start(Mycalc.java:32)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
... 1 more
    Exception running application mycalc.Mycalc

但是我在运行时收到以下消息：

$this->container->get('security.context')

我用AnchorPane root替换了父root，但我仍然遇到同样的错误。请帮忙。

Answer 1

引起：java.lang.ClassCastException： javafx.scene.layout.AnchorPane无法强制转换为 javafx.fxml.FXMLLoader

而不是：

FXMLLoader loader= FXMLLoader.load(getClass().getResource("calc1.fxml"));
Parent root = loader.load();

尝试（未经测试）

FXMLLoader loader= new FXMLLoader(getClass().getResource("calc1.fxml"));
Parent root = loader.load();

或（如果您的FXML根元素是AnchorPane）：

FXMLLoader loader= new FXMLLoader(getClass().getResource("calc1.fxml"));
AnchorPane root = loader.load();

FXMLLoader.load加载FXML文件。它没有返回FXMLLoader。

错误的javafx主要方法FXML加载没有得到纠正

1 个答案: