java - 在 main 中加载 fxml 文件

标签 java javafx fxml scenebuilder

我从 youtube 上完成了这个教程，我的代码与教程相同，但我使用 Scenebuilder 做了正确的 fxml。 这是代码:https://github.com/AlmasB/FXTutorials/tree/master/src/com/almasb/calc 我有相同的主控、相同的 Controller 和相同的型号.. 当我尝试编译时，它对我说:

`Exception in Application start method
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
    at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(Unknown Source)
    at com.sun.javafx.application.LauncherImpl$$Lambda$48/1394438858.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Location is required.
    at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
    at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
    at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
    at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
    at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
    at javafx.fxml.FXMLLoader.load(Unknown Source)
    at application.Main.start(Main.java:12)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(Unknown Source)
    at com.sun.javafx.application.LauncherImpl$$Lambda$51/1252716230.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(Unknown Source)
    at com.sun.javafx.application.PlatformImpl$$Lambda$45/1775282465.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$null$164(Unknown Source)
    at com.sun.javafx.application.PlatformImpl$$Lambda$47/21202996.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(Unknown Source)
    at com.sun.javafx.application.PlatformImpl$$Lambda$46/2040495657.run(Unknown Source)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$141(Unknown Source)
    at com.sun.glass.ui.win.WinApplication$$Lambda$37/1558600329.run(Unknown Source)
    ... 1 more
Exception running application application.Main

package application;

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

这是我的主要:

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

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) {
       try {
        FXMLLoader loader = new FXMLLoader(getClass().getResource("view/Calculatorview.fxml"));
  //    Parent root = FXMLLoader.load(getClass().getResource("view/Calculatorview.fxml"));
        AnchorPane root = (AnchorPane) loader.load();
        Scene scene = new Scene(root);

        primaryStage.setScene(scene);
        primaryStage.show();
    } 
       catch(Exception e)    {
        e.printStackTrace();
    }
    }
    public static void main(String[] args) {
      launch(args);
    }
}

这是我的 fxml 文件:

   <?xml version="1.0" encoding="UTF-8"?>

<?import javafx.embed.swing.*?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<fx:root maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="640.0" type="AnchorPane" xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.Controller">
   <children>
      <AnchorPane prefHeight="600.0" prefWidth="700.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
         <children>
            <SplitPane dividerPositions="0.19063545150501673" layoutX="149.0" layoutY="32.0" orientation="VERTICAL" prefHeight="600.0" prefWidth="500.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
              <items>
                <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
                     <children>
                        <TextField alignment="CENTER_RIGHT" prefHeight="73.0" prefWidth="638.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                           <font>
                              <Font size="47.0" />
                           </font>
                        </TextField>
                     </children>
                  </AnchorPane>
                <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="515.0" prefWidth="498.0">
                     <children>
                        <GridPane layoutX="90.0" layoutY="116.0" prefHeight="319.0" prefWidth="638.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                          <columnConstraints>
                              <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                            <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                              <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                              <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                              <ColumnConstraints hgrow="SOMETIMES" maxWidth="116.0" minWidth="10.0" prefWidth="95.0" />
                              <ColumnConstraints hgrow="SOMETIMES" maxWidth="116.0" minWidth="10.0" prefWidth="95.0" />
                              <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                              <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                          </columnConstraints>
                          <rowConstraints>
                              <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                            <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                            <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                              <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                            <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                          </rowConstraints>
                           <effect>
                              <Blend />
                           </effect>
                           <children>
                              <Button mnemonicParsing="false" onAction="#processOperator" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="=" GridPane.columnIndex="7" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="620.0" layoutY="395.0" mnemonicParsing="false" onAction="#processOperator" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="+" GridPane.columnIndex="7" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="620.0" layoutY="299.0" mnemonicParsing="false" onAction="#processOperator" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="-" GridPane.columnIndex="7" GridPane.rowIndex="2">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="620.0" layoutY="203.0" mnemonicParsing="false" onAction="#processOperator" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="×" GridPane.columnIndex="7" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="620.0" layoutY="107.0" mnemonicParsing="false" onAction="#processOperator" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="÷" GridPane.columnIndex="7">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="532.0" layoutY="395.0" mnemonicParsing="false" prefHeight="70.0" prefWidth="76.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="C" GridPane.columnIndex="4" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="358.0" layoutY="395.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="0" GridPane.columnIndex="5" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="362.0" layoutY="395.0" mnemonicParsing="false" prefHeight="69.0" prefWidth="88.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="M-" GridPane.columnIndex="4">
                                 <font>
                                    <Font size="28.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="e" GridPane.columnIndex="1" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="1/x" GridPane.columnIndex="3" GridPane.rowIndex="4">
                                 <font>
                                    <Font name="System" size="28.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="√" GridPane.columnIndex="3" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="MC" GridPane.columnIndex="3" GridPane.rowIndex="2">
                                 <font>
                                    <Font name="System" size="28.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="M+" GridPane.columnIndex="3" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="27.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="x²" GridPane.columnIndex="2" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="tan" GridPane.columnIndex="2" GridPane.rowIndex="2">
                                 <font>
                                    <Font name="System" size="28.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="sin" GridPane.columnIndex="2" GridPane.rowIndex="1">
                                 <font>
                                    <Font name="System" size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="xʸ" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="log" GridPane.rowIndex="2">
                                 <font>
                                    <Font name="System" size="28.0" />
                                 </font>
                              </Button>
                              <Button graphicTextGap="0.0" layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="cos" GridPane.columnIndex="2">
                                 <font>
                                    <Font name="System" size="26.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text=")">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button alignment="CENTER" layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="x³" GridPane.columnIndex="2" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="98.0" layoutY="11.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="(" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="64.0" prefWidth="95.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="3" GridPane.columnIndex="6" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="2" GridPane.columnIndex="5" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="64.0" prefWidth="96.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="6" GridPane.columnIndex="6" GridPane.rowIndex="2">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="64.0" prefWidth="98.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="9" GridPane.columnIndex="6" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="8" GridPane.columnIndex="5" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" prefHeight="64.0" prefWidth="96.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="±" GridPane.columnIndex="5">
                                 <font>
                                    <Font size="29.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="58.0" prefWidth="76.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="1" GridPane.columnIndex="4" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="4" GridPane.columnIndex="4" GridPane.rowIndex="2">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="5" GridPane.columnIndex="5" GridPane.rowIndex="2">
                                 <font>
                                    <Font size="35.0" />
                                 </font>
                              </Button>
                              <Button layoutX="10.0" layoutY="11.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="7" GridPane.columnIndex="4" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="619.0" layoutY="395.0" mnemonicParsing="false" prefHeight="100.0" prefWidth="81.0" style="-fx-background-color: #EE543A; -fx-text-fill: #FFFFFF;" text="\%" GridPane.columnIndex="6">
                                 <font>
                                    <Font size="29.0" />
                                 </font>
                              </Button>
                              <Button mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="π" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="462.0" layoutY="202.0" mnemonicParsing="false" onAction="#processNumpad" prefHeight="64.0" prefWidth="95.0" style="-fx-background-color: #9E9D9B; -fx-text-fill: #FFFFFF;" text="." GridPane.columnIndex="6" GridPane.rowIndex="4">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button graphicTextGap="0.0" layoutX="172.0" layoutY="10.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="cosh" GridPane.columnIndex="1">
                                 <font>
                                    <Font name="System" size="22.0" />
                                 </font>
                              </Button>
                              <Button layoutX="172.0" layoutY="74.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="sinh" GridPane.columnIndex="1" GridPane.rowIndex="1">
                                 <font>
                                    <Font size="25.0" />
                                 </font>
                              </Button>
                              <Button layoutX="172.0" layoutY="138.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="tanh" GridPane.columnIndex="1" GridPane.rowIndex="2">
                                 <font>
                                    <Font name="System" size="24.0" />
                                 </font>
                              </Button>
                              <Button layoutX="91.0" layoutY="266.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="10ʸ" GridPane.columnIndex="1" GridPane.rowIndex="3">
                                 <font>
                                    <Font size="30.0" />
                                 </font>
                              </Button>
                              <Button layoutX="253.0" layoutY="74.0" mnemonicParsing="false" prefHeight="96.0" prefWidth="92.0" style="-fx-background-color: #60646D; -fx-text-fill: #FFFFFF;" text="MR" GridPane.columnIndex="3">
                                 <font>
                                    <Font size="28.0" />
                                 </font>
                              </Button>
                           </children>
                        </GridPane>
                     </children>
                  </AnchorPane>
              </items>
            </SplitPane>
         </children>
      </AnchorPane>
   </children>
</fx:root>

新主线: structure

最佳答案

好吧。我尝试使用 Java 1.8 设置我的环境，并尝试了提供的链接中的教程。这就是我所做的。

  1. 已安装 Elcipse Kepler (Java EE)
  2. 按照此处的 e(fx)clipse 说明 https://www.eclipse.org/efxclipse/install.html
  3. 安装了所有库/jar，如下所示

enter image description here

上面之后，我在 eclipse 中创建了一个新的 Java 项目。我右键单击该项目并创建了两个源文件夹，即

src/main/java 
src/main/resources

然后我右键单击 src/main/java 并创建新包并将其命名为 application。在应用程序下，我创建了 4 个 java 类，并复制了教程链接中的内容。我确实修改了每个 java 文件顶部的包以仅反射(reflect)应用程序。

这是java类

package application;

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

public class App extends Application {

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

        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }

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

Controller 

 package application;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.text.Text;

public class Controller {

    @FXML
    private Text output;

    private long number1 = 0;
    private String operator = "";
    private boolean start = true;

    private Model model = new Model();

    @FXML
    private void processNumpad(ActionEvent event) {
        if (start) {
            output.setText("");
            start = false;
        }

        String value = ((Button)event.getSource()).getText();
        output.setText(output.getText() + value);
    }

    @FXML
    private void processOperator(ActionEvent event) {
        String value = ((Button)event.getSource()).getText();

        if (!"=".equals(value)) {
            if (!operator.isEmpty())
                return;

            operator = value;
            number1 = Long.parseLong(output.getText());
            output.setText("");
        }
        else {
            if (operator.isEmpty())
                return;

            output.setText(String.valueOf(model.calculate(number1, Long.parseLong(output.getText()), operator)));
            operator = "";
            start = true;
        }
    }
}

型号

package application;

public class Model {

    public long calculate(long number1, long number2, String operator) {
        switch (operator) {
            case "+":
                return number1 + number2;
            case "-":
                return number1 - number2;
            case "*":
                return number1 * number2;
            case "/":
                if (number2 == 0)
                    return 0;

                return number1 / number2;
        }

        System.out.println("Unknown operator - " + operator);
        return 0;
    }
}

和 ui.fxml 

<?xml version="1.0" encoding="UTF-8"?>

<?import java.net.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.beans.property.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.shape.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.paint.Color?>

<VBox spacing="10" alignment="CENTER" prefWidth="300" prefHeight="300" fx:controller="application.Controller" xmlns:fx="http://javafx.com/fxml">
    <fx:define>
        <Font fx:id="FONT" size="18" />
    </fx:define>

    <StackPane alignment="CENTER">
        <Rectangle fill="TRANSPARENT" stroke="GRAY" width="230" height="50" />
        <Text fx:id="output" font="$FONT" />
    </StackPane>

    <HBox spacing="10" alignment="CENTER">
        <Button text="7" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="8" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="9" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="/" prefWidth="50" font="$FONT" onAction="#processOperator" />
    </HBox>

    <HBox spacing="10" alignment="CENTER">
        <Button text="4" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="5" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="6" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="*" prefWidth="50" font="$FONT" onAction="#processOperator" />
    </HBox>

    <HBox spacing="10" alignment="CENTER">
        <Button text="1" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="2" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="3" prefWidth="50" font="$FONT" onAction="#processNumpad" />
        <Button text="-" prefWidth="50" font="$FONT" onAction="#processOperator" />
    </HBox>

    <HBox spacing="10" alignment="CENTER">
        <Button text="0" prefWidth="110" font="$FONT" onAction="#processNumpad" />
        <Button text="=" prefWidth="50" font="$FONT" onAction="#processOperator" />
        <Button text="+" prefWidth="50" font="$FONT" onAction="#processOperator" />
    </HBox>

</VBox>

我遇到了 Java 源库(引用 JRE)和 jfxrt.jar 文件的问题。所以我做了以下事情

  1. 删除了引用的库
  2. 删除了引用的外部 jar
  3. 右键单击该项目并选择属性
  4. 选择Java 构建路径
  5. 点击窗口右侧的添加库，添加JRE系统库，如下所示
  6. 添加了外部 jar jfxrt.jar

enter image description here

添加上述代码后，代码已解决，没有任何问题。

请记住，我将 ui.fxml 放置在 src/main/resources 文件夹下。因此，当我最初将项目作为 Java 应用程序 运行时，它会提示并给出与您所面临的相同的异常。所以我将“ui.fxml”更改为“/ui.fxml”，然后，我看到了计算器。 

Parent root = FXMLLoader.load(getClass().getResource("/ui.fxml"));

请参阅下面的屏幕截图，希望这些步骤有所帮助。

enter image description here

关于java - 在 main 中加载 fxml 文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33683302/

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