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JavaFX 2.2 InvocationTargetException问题

2014-02-28 67 views
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为了演示目的，我正在编写一个小应用程序（一个简单的计算器），我在下面的类中遇到了一些问题。每当我尝试运行该应用程序时，都会得到由initialize（）中的按钮引起的InvocationTargetException。调用按钮的任何方法都会重现该问题。JavaFX 2.2 InvocationTargetException问题

任何帮助，高度赞赏。

package ui; 

import java.io.IOException; 
import javafx.application.Platform; 
import javafx.event.ActionEvent; 
import javafx.event.EventHandler; 
import javafx.fxml.FXML; 
import javafx.fxml.FXMLLoader; 
import javafx.scene.control.Button; 
import javafx.scene.control.TextArea; 
import javafx.scene.layout.GridPane; 

public class CalculatorController extends GridPane { 

    @FXML 
    private TextArea displayArea; 

    @FXML 
    private Button mcButton, mrButton, msButton, mPlusButton, mMinusButton, 
      deleteButton, clearEverythingButton, clearButton, negateButton, 
      sqrtButton, sevenButton, eightButton, nineButton, divideButton, 
      percentButton, fourButton, fiveButton, sixButton, multiplyButton, 
      reciprocButton, oneButton, twoButton, threeButton, minusButton, 
      resultButton, zeroButton, fractionButton, plusButton; 

    @SuppressWarnings("LeakingThisInConstructor") 
    public CalculatorController() { 
     final FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("Calculator.fxml")); 
     fxmlLoader.setRoot(this); 
     fxmlLoader.setController(this); 
     try { 
      fxmlLoader.load(); 
     } catch (IOException e) { 
      System.out.println(e); 
      Platform.exit(); 
     } 
    } 

    @FXML 
    private void initialize() { 
     // do something with the buttons here to reproduce exception 
     // e.g. call any of their methods 
    } 

}

我的主类：

package main; 

import javafx.application.Application; 
import javafx.scene.Parent; 
import javafx.scene.Scene; 
import javafx.stage.Stage; 
import ui.CalculatorController; 

public class Main extends Application { 

    @Override 
    public void start(Stage stage) throws Exception { 
     stage.setTitle("Calculator"); 
     Parent root = new CalculatorController(); 
     stage.setScene(new Scene(root, 217, 306)); 
     stage.setResizable(false); 
     stage.show(); 
    } 

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

}

最后的FXML：

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

<?import java.lang.*?> 
<?import java.util.*?> 
<?import javafx.geometry.*?> 
<?import javafx.scene.*?> 
<?import javafx.scene.control.*?> 
<?import javafx.scene.layout.*?> 
<?import javafx.scene.text.*?> 

<fx:root type="javafx.scene.layout.GridPane" alignment="CENTER" hgap="2.0" prefHeight="306.0" prefWidth="217.0" vgap="2.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/2.2"> 
    <children> 
    <Button fx:id="mcButtton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="MC" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.rowIndex="2" /> 
    <Button fx:id="mrButtton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="MR" textAlignment="CENTER" GridPane.columnIndex="1" GridPane.rowIndex="2" /> 
    <Button fx:id="msButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="MS" textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="2" /> 
    <Button fx:id="mPlusButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="M+" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="2" /> 
    <Button fx:id="mMinusButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="M-" textAlignment="CENTER" GridPane.columnIndex="4" GridPane.rowIndex="2" /> 
    <Button fx:id="deleteButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="⬅" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.rowIndex="3"> 
     <font> 
     <Font size="14.0" /> 
     </font> 
    </Button> 
    <Button fx:id="clearEverythingButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="CE" textAlignment="CENTER" GridPane.columnIndex="1" GridPane.rowIndex="3" /> 
    <Button fx:id="clearButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="C" textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="3" /> 
    <Button fx:id="negateButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="±" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="3" /> 
    <Button fx:id="sqrtButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="√" textAlignment="CENTER" GridPane.columnIndex="4" GridPane.rowIndex="3" /> 
    <Button fx:id="sevenButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="7" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.rowIndex="4" /> 
    <Button fx:id="eightButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="8" textAlignment="CENTER" GridPane.columnIndex="1" GridPane.rowIndex="4" /> 
    <Button fx:id="nineButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="9" textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="4" /> 
    <Button fx:id="divideButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="/" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="4" /> 
    <Button fx:id="percentButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="\%" textAlignment="CENTER" GridPane.columnIndex="4" GridPane.rowIndex="4" /> 
    <Button fx:id="fourButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="4" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.rowIndex="5" /> 
    <Button fx:id="fiveButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="5" textAlignment="CENTER" GridPane.columnIndex="1" GridPane.rowIndex="5" /> 
    <Button fx:id="sixButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="6" textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="5" /> 
    <Button fx:id="multiplyButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="*" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="5" /> 
    <Button fx:id="reciprocButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="1/x" textAlignment="CENTER" GridPane.columnIndex="4" GridPane.rowIndex="5" /> 
    <Button fx:id="oneButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="1" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.rowIndex="6" /> 
    <Button fx:id="twoButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="2" textAlignment="CENTER" GridPane.columnIndex="1" GridPane.rowIndex="6" /> 
    <Button fx:id="threeButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="3" textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="6" /> 
    <Button fx:id="minusButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="-" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="6" /> 
    <Button fx:id="zeroButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="0" textAlignment="CENTER" GridPane.columnIndex="0" GridPane.columnSpan="2" GridPane.rowIndex="7" /> 
    <Button fx:id="fractionButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="," textAlignment="CENTER" GridPane.columnIndex="2" GridPane.rowIndex="7" /> 
    <Button fx:id="plusButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="+" textAlignment="CENTER" GridPane.columnIndex="3" GridPane.rowIndex="7" /> 
    <Button fx:id="resultButton" alignment="CENTER" contentDisplay="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="=" textAlignment="CENTER" GridPane.columnIndex="4" GridPane.rowIndex="6" GridPane.rowSpan="2" /> 
    <TextArea fx:id="displayArea" prefWidth="200.0" wrapText="true" GridPane.columnIndex="0" GridPane.columnSpan="2147483647" GridPane.rowIndex="0" GridPane.rowSpan="2"> 
     <GridPane.margin> 
     <Insets bottom="5.0" /> 
     </GridPane.margin> 
    </TextArea> 
    </children> 
    <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" minWidth="10.0" prefWidth="100.0" /> 
    </columnConstraints> 
    <padding> 
    <Insets left="5.0" right="5.0" /> 
    </padding> 
    <rowConstraints> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    <RowConstraints maxHeight="30.0" minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> 
    </rowConstraints> 
</fx:root>

UPDATE：

所以，我终于找到了问题所在。 FXML中有两个按钮'fx：id错误输入。

来源

2014-02-28 Athelionas

回答

2

某些按钮是null的initialize()，因为在FXML中没有相应的fx:id元素。

为了具有这种注入：

@FXML private Button mcButton;

必须有一个<Button>与相应fx:id：

<Button fx:id="mcButton" ... />

例如主叫msButton.setText("XX");（msButton存在于FXML中）的作品。

来源

2014-02-28 15:51:28

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