学习使用 JavaFX 制作桌面应用程序。
当我为 button11 添加 onAction 时遇到问题,程序停止运行并开始给出以下类型的错误:
Exception in Application start method
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.RuntimeException: Exception in Application start method
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
at java.base/java.lang.Thread.run(Thread.java:835)
Caused by: javafx.fxml.LoadException: Root hasn't been set. Use method setRoot() before load.
/C:/Users/Desktop/Diplom_game/out/production/Diplom_game/scene.fxml:16
at javafx.fxml/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2621)
at javafx.fxml/javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:105)
at javafx.fxml/javafx.fxml.FXMLLoader$RootElement.constructValue(FXMLLoader.java:1338)
at javafx.fxml/javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:754)
at javafx.fxml/javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2722)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2552)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3237)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3194)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3163)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3136)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3113)
at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3106)
at Main.start(Main.java:11)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
... 1 more
Exception running application Main
我试图通过在 getResource() 中设置路径来解决问题 - 它没有帮助。这还可能与什么有关?控制器也在 fxml 中注册。
测试应用:
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class TestApplication extends javafx.application.Application {
@Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("scene.fxml"));
primaryStage.setTitle("XO-game");
primaryStage.setScene(new Scene(root, 165, 250));
primaryStage.setResizable(false);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
控制器:
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import java.awt.*;
import java.net.URL;
import java.util.ResourceBundle;
public class Controller implements Initializable {
@FXML Label going;
@FXML private Button button11;
@Override
public void initialize(URL url, ResourceBundle resourceBundle) {
}
@FXML
private void actionButton11(ActionEvent actionEvent) {
button11.setName("WOW");
going.setText("WOWOWOW");
}
}
我解决了如下问题:我用 VBox 替换了 fxml 文件中的 fx: root
它是:
它变成了:
出现问题是因为在 SceneBuilder 中我勾选了以下框: