javafx：javafx.scene.layout.AnchorPane无法强制转换为javafx.scene.layout.BorderPane

问题描述

嘿伙计们我知道javafx，我正在尝试将一个BorderPane转换为anchronPane，同时发生错误，我不知道该怎么做，我正在关注一个教程，所以请帮助

hey guys i am knew to javafx and i am trying to cast a BorderPane to an anchronPane, meanwhile an error occured and i don t know what to do, i was following a tutorial so please help

import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class MainApp extends Application {

    private Stage primaryStage;
    private BorderPane rootLayout;

    @Override
    public void start(Stage primaryStage) {
        this.primaryStage = primaryStage;
        this.primaryStage.setTitle("AddressApp");

        initRootLayout();
        showPersonOverview();
    }

    /**
     * Initializes the root layout.
     */
    public void initRootLayout() {
        try {
            // Load root layout from fxml file.
            FXMLLoader loader = new FXMLLoader();
            loader.setLocation(MainApp.class.getResource("view/RootLayout.fxml"));
            rootLayout = (BorderPane) loader.load();

            // Show the scene containing the root layout.
            Scene scene = new Scene(rootLayout);
            primaryStage.setScene(scene);
            primaryStage.show();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Shows the person overview inside the root layout.
     */
    public void showPersonOverview() {
        try {
            // Load person overview.
            FXMLLoader loader = new FXMLLoader();
            loader.setLocation(MainApp.class.getResource("view/PersonOverview.fxml"));
            AnchorPane personOverview = (AnchorPane) loader.load();

            // Set person overview into the center of root layout.
            rootLayout.setCenter(personOverview);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Returns the main stage.
     * @return
     */
    public Stage getPrimaryStage() {
        return primaryStage;
    }

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

我收到此错误

    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
atcom.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.scene.layout.BorderPane
at ch.makery.address.MainApp.initRootLayout(MainApp.java:35)
at ch.makery.address.MainApp.start(MainApp.java:22)
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$6.run(PlatformImpl.java:298)
atcom.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.ja    va: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

异常运行应用程序ch.makery.address.MainApp
Java结果：1

Exception running application ch.makery.address.MainApp Java Result: 1

所以，如果我不能投，那我该怎么做？

so if i cannot cast then what sould i do?

推荐答案

我也遵循相同的教程，并遇到了同样的问题。

I was following the same tutorial as well, and encountered the same issue.

在我的情况下，在创建RootLayout FXML时，我错误地选择了 AnchorPane 作为根元素而不是 BorderPane 。因此，在initRootLayout（）方法中，它尝试将AnchorPane对象转换为BorderPane对象。正如前面评论中提到的那样，AnchorPane和BorderPane扩展了Pane，它们不可能相互投射！

In my case, while creating the RootLayout FXML, I erroneously selected AnchorPane as the root element instead of BorderPane. So, in the initRootLayout() method, it tried to Cast AnchorPane object to BorderPane object. And as mentioned in the previous comment that, AnchorPane and BorderPane extend Pane, it is not possible to cast them with each other!

因此，如果选择 BorderPane 作为RootLayout.fxml的根元素，它正确地将对象强制转换为BorderPane。因此，现在我想知道，如果甚至需要这个演员？

Thus, if you select BorderPane as the root element for RootLayout.fxml, it correctly casts the object to BorderPane. Thus, now I am wondering, if this casting is even required?

我希望你的问题现在已经解决了。这可能对遇到此问题的其他人有所帮助！

I hope your issue is resolved by now. This might be helpful to someone else who encounters this problem!

这篇关于javafx：javafx.scene.layout.AnchorPane无法强制转换为javafx.scene.layout.BorderPane的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！