sProcessItem.addActionListener(new ActionListener(){ 未按预期运行答案

【问题标题】：sProcessItem.addActionListener(new ActionListener(){ Not Functioning As ExpectedsProcessItem.addActionListener(new ActionListener(){ 未按预期运行
【发布时间】：2013-09-11 05:30:04
【问题描述】：

问题：

在输入 3 个文本字段后运行我的程序时，您应该先单击 Process Item #1，然后单击确认 - 但是这不会按预期发生 - 当您单击 process Item 时，它什么也不做。

要求：

当点击处理项目 #1 时，我需要它来处理订单 - 我试图通过调用来实现这一点：

sProcessItem.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                sStoreAction.ProcessOrder(sCD, Integer.valueOf(sQuantityTF.getText()), Integer.valueOf(sNumItemsTF.getText()));
                if(sCurrentOrderNumber < Integer.valueOf(sNumItemsTF.getText())){
                    sNumItemsTF.setEditable(false);
                    sNumItemsTF.setEditable(false);
                    sConfirmItem.setEnabled(true);
                    sProcessItem.setEnabled(false);

                    sIDTF.setText("");
                    sQuantityTF.setText("");
                    sConfirmItem.setEnabled(false);
                    //sCurrentOrderNumber++;
                    RedrawLabels();
                }else{
                    sConfirmItem.setEnabled(false);
                    sProcessItem.setEnabled(false);
                }

完整来源：

package theCDstore;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;



public class Store_GUI {

    private  CDobject sCD;
    private  int sCurrentOrderNumber;
    private  JFrame sStoreWindow;
    private  JPanel sPanel;
    private  SpringLayout sLayout;
    private  Store_backend sStoreAction;

    private  JTextField sNumItemsTF;
    private  JTextField sIDTF;
    private  JTextField sQuantityTF;
    private  JTextField sItemInfoTF;
    private  JTextField sSubtotalTF;

    private  JLabel sNumItemsL;
    private  JLabel sIDL;
    private  JLabel sQuantityL;
    private  JLabel sItemInfoL;
    private  JLabel sSubtotalL;

    private  JButton sProcessItem;
    private  JButton sConfirmItem;
    private  JButton sViewOrder;
    private  JButton sFinishOrder;
    private  JButton sNewOrder;
    private  JButton sExit;

    /**
     * Starts the initialization of the JFrame, and initializes the StoreAction object.
     * @param args
     */
    public static void main(String[] args) {
        new Store_GUI().StartThread();
        sCurrentOrderNumber = 1;
        InitWindow();

    }

    /**
     * Sets many of the base attributes of the frame/panel and calls other methods to populate it.
     */
    private  void InitWindow(){
        sStoreWindow = new JFrame("Adrian's Wonderful World of Music");
        sPanel  = new JPanel();

        sPanel.setSize(1000, 300);
        sStoreWindow.setSize(1000, 300);

        InitButtons();

        InitLabels();

        InitText();

        InitPlacement();

        sStoreWindow.add(sPanel);
        sStoreWindow.setVisible(true);
    }

    /**
     * Initializes the JLabels and adds them to the panel.
     */
    private  void InitLabels(){
        sNumItemsL = new JLabel("Enter the number of items for this order:");
        sIDL = new JLabel("Enter CD ID for item #"+String.valueOf(sCurrentOrderNumber)+":");
        sQuantityL = new JLabel("Enter quantity for item #"+String.valueOf(sCurrentOrderNumber)+":");
        sItemInfoL = new JLabel("Item #"+String.valueOf(sCurrentOrderNumber)+" info:");
        sSubtotalL = new JLabel("Order subtotal for "+String.valueOf(sCurrentOrderNumber-1)+" item(s):");

        sPanel.add(sNumItemsL);
        sPanel.add(sIDL);
        sPanel.add(sQuantityL);
        sPanel.add(sItemInfoL);
        sPanel.add(sSubtotalL);
    }

    /**
     * Initializes the JTextFields and adds listeners to them.
     */
    private  void InitText(){
        sNumItemsTF = new JTextField(13);
        sIDTF = new JTextField(13);
        sQuantityTF = new JTextField(13);
        sItemInfoTF = new JTextField(40);
        sSubtotalTF = new JTextField(13);

        sIDTF.addKeyListener(new KeyListener(){

            @Override
            public void keyPressed(KeyEvent arg0) {

            }

            @Override
            public void keyReleased(KeyEvent arg0) {
                // TODO Auto-generated method stub

            }

            @Override
            public void keyTyped(KeyEvent arg0) {
                if((arg0.getKeyCode() == KeyEvent.VK_ENTER) && !sIDTF.getText().isEmpty()){
                    sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()));
                    if(!sQuantityTF.getText().isEmpty())
                        sStoreAction.SetCDInfo(sCD, Integer.valueOf(sQuantityTF.getText()));
                    else
                        sStoreAction.SetCDInfo(sCD, 1);
                    AutoComplete(sCD);
                }

            }});
        sIDTF.addFocusListener(new FocusListener(){

            @Override
            public void focusGained(FocusEvent e) {
                // TODO Auto-generated method stub

            }

            @Override
            public void focusLost(FocusEvent e) {
                if(!sIDTF.getText().isEmpty()){
                    sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()));

                    if(!sQuantityTF.getText().isEmpty())
                        sStoreAction.SetCDInfo(sCD, Integer.valueOf(sQuantityTF.getText()));
                    else
                        sStoreAction.SetCDInfo(sCD, 1);

                    AutoComplete(sCD);
                }
            }

        });
        sQuantityTF.addFocusListener(new FocusListener(){

            @Override
            public void focusGained(FocusEvent arg0) {
                // TODO Auto-generated method stub

            }

            @Override
            public void focusLost(FocusEvent arg0) {
                if(!sQuantityTF.getText().isEmpty() && !sIDTF.getText().isEmpty()){
//                  sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()),Integer.valueOf(sQuantityTF.getText()));
                    sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()));

                    sStoreAction.SetCDInfo(sCD, Integer.valueOf(sQuantityTF.getText()));

                    AutoComplete(sCD);
                }

            }});
        sQuantityTF.addKeyListener(new KeyListener(){

            @Override
            public void keyPressed(KeyEvent arg0) {

            }

            @Override
            public void keyReleased(KeyEvent arg0) {
                if(Character.isDigit(arg0.getKeyChar())){
//                  sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()),Integer.valueOf(sQuantityTF.getText()));
                    sCD = sStoreAction.FindCD(Integer.valueOf(sIDTF.getText()));
                    sStoreAction.SetCDInfo(sCD, Integer.valueOf(sQuantityTF.getText()));

                    AutoComplete(sCD);
                }
            }

            @Override
            public void keyTyped(KeyEvent arg0) {
            }});

        sItemInfoTF.setEnabled(false);
        sSubtotalTF.setEditable(false);

        sPanel.add(sNumItemsTF);
        sPanel.add(sIDTF);
        sPanel.add(sQuantityTF);
        sPanel.add(sItemInfoTF);
        sPanel.add(sSubtotalTF);
    }

    /**
     * Initializes the JButtons and adds listeners to them.
     */
    private  void InitButtons(){
        sProcessItem = new JButton("Process Item #"+String.valueOf(sCurrentOrderNumber)+"");
        sConfirmItem = new JButton("Confirm Item #"+String.valueOf(sCurrentOrderNumber)+"");
        sViewOrder = new JButton("View Order");
        sFinishOrder = new JButton("Finish Order");
        sNewOrder = new JButton("New Order");
        sExit = new JButton("Exit");

        sConfirmItem.setEnabled(false);
        sViewOrder.setEnabled(false);
        sFinishOrder.setEnabled(false);

        sProcessItem.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                sStoreAction.ProcessOrder(sCD, Integer.valueOf(sQuantityTF.getText()), Integer.valueOf(sNumItemsTF.getText()));
                if(sCurrentOrderNumber < Integer.valueOf(sNumItemsTF.getText())){
                    sNumItemsTF.setEditable(false);
                    sNumItemsTF.setEditable(false);
                    sConfirmItem.setEnabled(true);
                    sProcessItem.setEnabled(false);

                    sIDTF.setText("");
                    sQuantityTF.setText("");
                    sConfirmItem.setEnabled(false);
                    //sCurrentOrderNumber++;
                    RedrawLabels();
                }else{
                    sConfirmItem.setEnabled(false);
                    sProcessItem.setEnabled(false);
                }
            }});
        sConfirmItem.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                JOptionPane.showMessageDialog(sPanel,"Item #"+String.valueOf(sCurrentOrderNumber)+" accepted");
                sNumItemsTF.setEditable(false);
                sProcessItem.setEnabled(true);
                sConfirmItem.setEnabled(false);
            }});
        sViewOrder.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                JOptionPane.showMessageDialog(sPanel, sStoreAction.getDisplayViewOrder());
            }});
        sFinishOrder.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                JOptionPane.showMessageDialog(sPanel, sStoreAction.DisplayInvoice());
                sStoreAction.WriteInvoice();
                NewOrderClick();
            }});
        sNewOrder.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                NewOrderClick();
            }});
        sExit.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent arg0) {
                sStoreWindow.dispose();
            }});

        sPanel.add(sProcessItem);
        sPanel.add(sConfirmItem);
        sPanel.add(sViewOrder);
        sPanel.add(sFinishOrder);
        sPanel.add(sNewOrder);
        sPanel.add(sExit);
    }

    /**
     * Positions all of the objects in the JPanel using SpringLayout.
     */
    private  void InitPlacement(){
        sLayout = new SpringLayout();
        sLayout.putConstraint(SpringLayout.NORTH,sNumItemsL, 5, SpringLayout.NORTH,sPanel);
        sLayout.putConstraint(SpringLayout.NORTH,sNumItemsTF, 5, SpringLayout.NORTH,sPanel);
        sLayout.putConstraint(SpringLayout.WEST, sNumItemsL, 5, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.WEST, sNumItemsTF, 5, SpringLayout.EAST, sNumItemsL);

        sLayout.putConstraint(SpringLayout.NORTH,sIDL, 7, SpringLayout.SOUTH,sNumItemsL);
        sLayout.putConstraint(SpringLayout.WEST, sIDL, 5, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.NORTH, sIDTF, 5, SpringLayout.SOUTH, sNumItemsTF);
        sLayout.putConstraint(SpringLayout.WEST, sIDTF, 5, SpringLayout.EAST, sIDL);

        sLayout.putConstraint(SpringLayout.NORTH,sQuantityL, 10, SpringLayout.SOUTH,sIDL);
        sLayout.putConstraint(SpringLayout.WEST, sQuantityL, 5, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.NORTH, sQuantityTF, 5, SpringLayout.SOUTH, sIDTF);
        sLayout.putConstraint(SpringLayout.WEST, sQuantityTF, 5, SpringLayout.EAST, sQuantityL);

        sLayout.putConstraint(SpringLayout.NORTH,sItemInfoL, 10, SpringLayout.SOUTH,sQuantityL);
        sLayout.putConstraint(SpringLayout.WEST, sItemInfoL, 5, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.NORTH, sItemInfoTF, 5, SpringLayout.SOUTH, sQuantityTF);
        sLayout.putConstraint(SpringLayout.WEST, sItemInfoTF, 5, SpringLayout.EAST, sItemInfoL);

        sLayout.putConstraint(SpringLayout.NORTH,sSubtotalL, 10, SpringLayout.SOUTH,sItemInfoL);
        sLayout.putConstraint(SpringLayout.WEST, sSubtotalL, 5, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.NORTH, sSubtotalTF, 5, SpringLayout.SOUTH, sItemInfoTF);
        sLayout.putConstraint(SpringLayout.WEST, sSubtotalTF, 5, SpringLayout.EAST, sSubtotalL);

        sLayout.putConstraint(SpringLayout.NORTH, sProcessItem, 10, SpringLayout.SOUTH, sSubtotalL);
        sLayout.putConstraint(SpringLayout.NORTH, sConfirmItem, 10, SpringLayout.SOUTH, sSubtotalL);
        sLayout.putConstraint(SpringLayout.NORTH, sViewOrder, 10, SpringLayout.SOUTH, sSubtotalL);
        sLayout.putConstraint(SpringLayout.NORTH, sFinishOrder, 10, SpringLayout.SOUTH, sSubtotalL);
        sLayout.putConstraint(SpringLayout.NORTH, sNewOrder, 10, SpringLayout.SOUTH, sSubtotalL);
        sLayout.putConstraint(SpringLayout.NORTH, sExit, 10, SpringLayout.SOUTH, sSubtotalL);

        sLayout.putConstraint(SpringLayout.WEST, sProcessItem, 10, SpringLayout.WEST, sPanel);
        sLayout.putConstraint(SpringLayout.WEST, sConfirmItem, 10, SpringLayout.EAST, sProcessItem);
        sLayout.putConstraint(SpringLayout.WEST, sViewOrder, 10, SpringLayout.EAST, sConfirmItem);
        sLayout.putConstraint(SpringLayout.WEST, sFinishOrder, 10, SpringLayout.EAST, sViewOrder);
        sLayout.putConstraint(SpringLayout.WEST, sNewOrder, 10, SpringLayout.EAST, sFinishOrder);
        sLayout.putConstraint(SpringLayout.WEST, sExit, 10, SpringLayout.EAST, sNewOrder);

        sPanel.setLayout(sLayout);
    }

    /**
     * Auto fills the Info, Subtotal, and if necessary the Quantity text boxes.
     * @param mCD The current CD object.
     */
    private  void AutoComplete(CDobject mCD){
        sItemInfoTF.setText(mCD.getInfo());
        if(!sQuantityTF.getText().isEmpty())
            sSubtotalTF.setText(String.valueOf(sStoreAction.getDisplaySubtotal(mCD, Integer.valueOf(sQuantityTF.getText()))));
        else{
            sQuantityTF.setText("1");
            sSubtotalTF.setText(String.valueOf(sStoreAction.getDisplaySubtotal(mCD,1)));
        }
    }

    /**
     * Updates the items number of many of the labels based on the sCurrentOrderNumber.
     */
    private  void RedrawLabels(){
        sProcessItem.setText("Process Item #"+String.valueOf(sCurrentOrderNumber)+"");
        sConfirmItem.setText("Confirm Item #"+String.valueOf(sCurrentOrderNumber)+"");
        sIDL.setText("Enter CD ID for item #"+String.valueOf(sCurrentOrderNumber)+":");
        sQuantityL.setText("Enter quantity for item #"+String.valueOf(sCurrentOrderNumber)+":");
        sItemInfoL.setText("Item #"+String.valueOf(sCurrentOrderNumber)+" info:");
        sSubtotalL.setText("Order subtotal for "+String.valueOf(sCurrentOrderNumber-1)+" item(s):");
    }

    /**
     * Clears the text fields, reinitializes the StoreAction object, and redraws the labels.
     */
    private  void NewOrderClick(){
        new Store_GUI().StartThread();
        sCurrentOrderNumber = 1;

        sIDTF.setText("");
        sQuantityTF.setText("");
        sItemInfoTF.setText("");
        sSubtotalTF.setText("");
        sNumItemsTF.setText("");

        RedrawLabels();

        sNumItemsTF.setEditable(true);
        sConfirmItem.setEnabled(true);
        sProcessItem.setEnabled(false);
    }


    /**
     * Defines a new class to execute the initialization of Store Action on its own thread.
     * @author david
     */
    class NewThread extends Thread{
        @Override
        public void run() {
            sStoreAction = new Store_backend();
        }
    }

    /**
     * Starts the thread.
     */
    private void StartThread(){
        new NewThread().start();
    }

}


RESULTS (after removing static):

Error: 

    Main method is not static in class theCDstore.Store_GUI, please define the main method as:
       public static void main(String[] args)

【问题讨论】：

您是否尝试过在 IDE 调试器中运行它并单步执行代码？没有人会阅读所有内容来找到您的问题。请阅读FAQ 和How to Ask，了解如何编写好问题。
是的 - 当我在 NewOrderClick() 处设置断点时； }else{ 它运行在它上面，但从不启动我的 NewOrderClick 方法感谢专业提示 - 但我已经阅读了它。
“专业”提示 #2：摆脱所有这些静态因素。
哪个静态？除 main 方法外的所有方法。
您的问题是，在您的主要方法中，您试图以静态方式访问类的实例字段和方法，这是错误的。不要那样做。在 main 方法中创建并初始化一个 Store_GUI 变量，在这个实例上调用startThread()，然后在实例上调用initWindow()。不要在没有实例的情况下调用它，因为那时您正试图以静态方式访问该方法。并且永远不要直接从另一个类中操作你的类的字段。说白了，做你正在做的事情是非常糟糕的形式，并且会给你一个无法扩展的程序。

标签： java swing awt actionlistener

【解决方案1】：

根据您的 cmets：

仅供参考 - 当我将我的主要方法更改为静态并保留所有其他非静态时，我收到一条错误消息：无法对非静态字段 sCurrentOrderNumber 进行静态引用，并且无法对非静态字段进行静态引用-Store_GUI Store_GUI.java*strong text*
类型的静态方法 InitWindow()

我已经在你上面的评论中提到了这一点：

您的问题是，在您的主要方法中，您试图以静态方式访问类的实例字段和方法，这是错误的。不要那样做。在 main 方法中创建并初始化一个 Store_GUI 变量，在这个实例上调用startThread()，然后在实例上调用initWindow()。不要在没有实例的情况下调用它，因为那时您正试图以静态方式访问该方法。并且永远不要直接从另一个类中操作你的类的字段。

再一次，通过将所有内容都设置为静态，您正在修复错误的问题。解决方案不是让变量和方法成为静态，而是避免尝试以静态方式访问它们。

即，

public static void main(String[] args) {
  Store_GUI store = new Store_GUI();
  store.StartThread();
  store.InitWindow();

  // !! new Store_GUI().StartThread();
  // sCurrentOrderNumber = 1;
  // InitWindow();
}

这与 Swing 或 GUI 无关，而与基本的编程技术有关。

【讨论】：