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JavaFX 2.2 InvocationTargetException問題

2014-02-28 66 views
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爲了演示目的，我正在編寫一個小應用程序（一個簡單的計算器），我在下面的類中遇到了一些問題。每當我嘗試運行該應用程序時，都會得到由initialize（）中的按鈕引起的InvocationTargetException。調用按鈕的任何方法都會重現該問題。JavaFX 2.2 InvocationTargetException問題

任何幫助，高度讚賞。

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 
    } 

}

我的主類：

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); 
    } 

}

最後的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，我終於找到了問題所在。 FXML中有兩個按鈕'fx：id錯誤輸入。

來源

2014-02-28 Athelionas

回答

2

某些按鈕是null的initialize()，因爲在FXML中沒有相應的fx:id元素。

爲了具有這種注入：

@FXML private Button mcButton;

必須有一個<Button>與相應fx:id：

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

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

來源

2014-02-28 15:51:28

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