在 main 中加载 fxml 文件
Loading fxml file in main
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 完成了正确的 fxml。
这是代码：https://github.com/AlmasB/FXTutorials/tree/master/src/com/almasb/calc
我有相同的主、相同的控制器和相同的模型..
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$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication7(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda/1394438858.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Location is required.
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.load(Unknown Source)
at application.Main.start(Main.java:12)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication13(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda/1252716230.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait6(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/1775282465.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null4(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/21202996.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater5(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/2040495657.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null1(Unknown Source)
at com.sun.glass.ui.win.WinApplication$$Lambda/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;
这是我的主要内容:
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
NullPointerException: Location is required
从您调用 FXMLLoader.load(...) 的行表明您为 FXML 文件提供的 URL 是 null：即资源路径不正确。
getClass().getResource() 将在相对于当前 class 的 class 路径上搜索资源。根据您链接的屏幕截图，Main 在包 appication 中，Calculatorview.fxml 在 application.view 中。所以你需要
Parent root = FXMLLoader.load(getClass().getResource("view/Calculatorview.fxml"));
或者，您可以指定相对于 class 路径（而不是相对于当前 class 路径）的 fxml 文件：
Parent root = FXMLLoader.load(getClass().getResource("/application/view/Calculatorview.fxml"));
（注意与您的代码相比额外的前导 /）。
当然要注意，这个路径是在运行时搜索的，所以你需要确保fxml文件和class文件一起部署代码已编译。换句话说，如果 Main 和 Calculatorview.fxml 在包 application 中，您应该在某处有一个名为 application 的文件夹，其中包含 Main.class（注意，class 文件）和 Calculatorview.fxml。这通常位于名为 bin 或 classes 的文件夹中，具体取决于您的 IDE 及其设置（或者您将在 jar 文件中具有 application 结构，如果您正在建造一个罐子）。
好的。我尝试使用 Java 1.8 设置我的环境，并尝试了提供的 link 中的教程。这是我所做的。
- 已安装 Elcipse Kepler（Java EE）
- 按照此处关于 e(fx)clipse 的说明进行操作 https://www.eclipse.org/efxclipse/install.html
- 安装了所有 libs/jars 如下所示
在上面之后，我在eclipse 中新建了一个Java 项目。我右键单击项目并创建了两个 Source Folders 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 java 类 并复制了教程 link 中的内容。我确实修改了每个 java 文件顶部的包以仅反映 应用程序 。
这里是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);
}
}
控制器
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
- 删除了引用的库
- 删除了引用的外部 jar
- 右键单击项目并选择 属性
- 选择Java构建路径
- 点击window右侧的Add Library，添加JRE System Library如下图
- 添加了外部 jar jfxrt.jar
加上上面的后，代码就解决了，没有任何问题。
记住，我把ui.fxml放在了src/main/resources文件夹下。因此，当我最初 运行 项目作为 Java Application 时，它抱怨并给我与您所面临的相同的异常。所以我将 "ui.fxml" 更改为“/ui.fxml” 砰的一声，我看到了计算器。
Parent root = FXMLLoader.load(getClass().getResource("/ui.fxml"));
请参见下面的屏幕截图，希望这些步骤对您有所帮助。
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 完成了正确的 fxml。 这是代码：https://github.com/AlmasB/FXTutorials/tree/master/src/com/almasb/calc 我有相同的主、相同的控制器和相同的模型.. 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$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication7(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda/1394438858.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Location is required.
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.load(Unknown Source)
at application.Main.start(Main.java:12)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication13(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda/1252716230.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait6(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/1775282465.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null4(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/21202996.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater5(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda/2040495657.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null1(Unknown Source)
at com.sun.glass.ui.win.WinApplication$$Lambda/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;
这是我的主要内容:
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
NullPointerException: Location is required
从您调用 FXMLLoader.load(...) 的行表明您为 FXML 文件提供的 URL 是 null：即资源路径不正确。
getClass().getResource() 将在相对于当前 class 的 class 路径上搜索资源。根据您链接的屏幕截图，Main 在包 appication 中，Calculatorview.fxml 在 application.view 中。所以你需要
Parent root = FXMLLoader.load(getClass().getResource("view/Calculatorview.fxml"));
或者，您可以指定相对于 class 路径（而不是相对于当前 class 路径）的 fxml 文件：
Parent root = FXMLLoader.load(getClass().getResource("/application/view/Calculatorview.fxml"));
（注意与您的代码相比额外的前导 /）。
当然要注意，这个路径是在运行时搜索的，所以你需要确保fxml文件和class文件一起部署代码已编译。换句话说，如果 Main 和 Calculatorview.fxml 在包 application 中，您应该在某处有一个名为 application 的文件夹，其中包含 Main.class（注意，class 文件）和 Calculatorview.fxml。这通常位于名为 bin 或 classes 的文件夹中，具体取决于您的 IDE 及其设置（或者您将在 jar 文件中具有 application 结构，如果您正在建造一个罐子）。
好的。我尝试使用 Java 1.8 设置我的环境，并尝试了提供的 link 中的教程。这是我所做的。
- 已安装 Elcipse Kepler（Java EE）
- 按照此处关于 e(fx)clipse 的说明进行操作 https://www.eclipse.org/efxclipse/install.html
- 安装了所有 libs/jars 如下所示
在上面之后，我在eclipse 中新建了一个Java 项目。我右键单击项目并创建了两个 Source Folders 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 java 类 并复制了教程 link 中的内容。我确实修改了每个 java 文件顶部的包以仅反映 应用程序 。
这里是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);
}
}
控制器
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
- 删除了引用的库
- 删除了引用的外部 jar
- 右键单击项目并选择 属性
- 选择Java构建路径
- 点击window右侧的Add Library，添加JRE System Library如下图
- 添加了外部 jar jfxrt.jar
加上上面的后，代码就解决了，没有任何问题。
记住，我把ui.fxml放在了src/main/resources文件夹下。因此，当我最初 运行 项目作为 Java Application 时，它抱怨并给我与您所面临的相同的异常。所以我将 "ui.fxml" 更改为“/ui.fxml” 砰的一声，我看到了计算器。
Parent root = FXMLLoader.load(getClass().getResource("/ui.fxml"));
请参见下面的屏幕截图，希望这些步骤对您有所帮助。