java - 如何从 keyevent 方法调用文本字段变量？

Question

好吧，我正在做一个 GUI 程序，但我无法检索用户将输入的信息并从另一个类调用它，以便可以在那里访问它。这是我的 GUI 类的主要部分，它从创建第一个文本字段开始:

/**
*Text genereted by Simple GUI Extension for BlueJ
*/
import javax.swing.UIManager.LookAndFeelInfo;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import javax.swing.border.Border;
import javax.swing.*;


public class GUI_project extends JFrame {

private JMenuBar menuBar;
private JButton button1;
private JLabel label1;
private JLabel label2;
private JLabel label3;
private JLabel label4;
private JTextField textfield1;
private JTextField textfield2;
private JTextField textfield3;
public String SoftName;
public String ReportName;
public String Devices;
public int InDevices;

//Constructor 
public GUI_project(){

    setTitle("Software Calculator");
    setSize(500,400);
    //menu generate method
    generateMenu();
    setJMenuBar(menuBar);

    //pane with null layout
    JPanel contentPane = new JPanel(null);
    contentPane.setPreferredSize(new Dimension(500,400));
    contentPane.setBackground(new Color(51,153,0));


    button1 = new JButton();
    button1.setBounds(180,325,150,35);
    button1.setBackground(new Color(214,217,223));
    button1.setForeground(new Color(0,0,0));
    button1.setEnabled(true);
    button1.setFont(new Font("sansserif",0,12));
    button1.setText("Calculate and Save");
    button1.setVisible(true);
    //Set action for key events
    //Call defined method
    button1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            startApp(evt);
        }
    });


    label1 = new JLabel();
    label1.setBounds(95,12,300,35);
    label1.setBackground(new Color(214,217,223));
    label1.setForeground(new Color(0,0,0));
    label1.setEnabled(true);
    label1.setFont(new Font("SansSerif",0,20));
    label1.setText("Software Agreement Calcuator");
    label1.setVisible(true);

    label2 = new JLabel();
    label2.setBounds(18,102,150,35);
    label2.setBackground(new Color(214,217,223));
    label2.setForeground(new Color(0,0,0));
    label2.setEnabled(true);
    label2.setFont(new Font("SansSerif",0,16));
    label2.setText("Name of Software:");
    label2.setVisible(true);

    label3 = new JLabel();
    label3.setBounds(15,174,300,35);
    label3.setBackground(new Color(214,217,223));
    label3.setForeground(new Color(0,0,0));
    label3.setEnabled(true);
    label3.setFont(new Font("SansSerif",0,16));
    label3.setText("Number of Devices the Software is on:");
    label3.setVisible(true);

    label4 = new JLabel();
    label4.setBounds(17,244,250,35);
    label4.setBackground(new Color(214,217,223));
    label4.setForeground(new Color(0,0,0));
    label4.setEnabled(true);
    label4.setFont(new Font("SansSerif",0,15));
    label4.setText("Name of Report to Save Under:");
    label4.setVisible(true);

    textfield1 = new JTextField();
    textfield1.setBounds(335,102,90,35);
    textfield1.setBackground(new Color(255,255,255));
    textfield1.setForeground(new Color(0,0,0));
    textfield1.setEnabled(true);
    textfield1.setFont(new Font("sansserif",0,12));
    textfield1.setText("");
    textfield1.setVisible(true);
    //Set action for key events
    //Call defined method
    textfield1.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent evt) {
            getSoftwareName(evt);
        }
    });


    textfield2 = new JTextField();
    textfield2.setBounds(335,173,90,35);
    textfield2.setBackground(new Color(255,255,255));
    textfield2.setForeground(new Color(0,0,0));
    textfield2.setEnabled(true);
    textfield2.setFont(new Font("sansserif",0,12));
    textfield2.setText("");
    textfield2.setVisible(true);
    //Set action for key events
    //Call defined method
    textfield2.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent evt) {
            number(evt);
        }
    });


    textfield3 = new JTextField();
    textfield3.setBounds(336,240,90,35);
    textfield3.setBackground(new Color(255,255,255));
    textfield3.setForeground(new Color(0,0,0));
    textfield3.setEnabled(true);
    textfield3.setFont(new Font("sansserif",0,12));
    textfield3.setText("");
    textfield3.setVisible(true);
    //Set action for key events
    //Call defined method
    textfield3.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent evt) {
            FileName(evt);
        }
    });


    //adding components to contentPane panel
    contentPane.add(button1);
    contentPane.add(label1);
    contentPane.add(label2);
    contentPane.add(label3);
    contentPane.add(label4);
    contentPane.add(textfield1);
    contentPane.add(textfield2);
    contentPane.add(textfield3);

    //adding panel to JFrame and seting of window position and close operation
    getContentPane().add(contentPane);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);
    pack();
    setVisible(true);
}

//Method keyPressed for button1
public void startApp (ActionEvent evt) {
        Print.Start();
}

//Method actionPerformed for textfield1
public String getSoftwareName (KeyEvent evt) {
        SoftName = textfield1.getText();
        return SoftName;
}

//Method actionPerformed for textfield2

  public int number (KeyEvent evt) {
        char c=evt.getKeyChar();
        if(!(Character.isDigit(c) || (c==KeyEvent.VK_BACK_SPACE)||c==KeyEvent.VK_DELETE)){
            evt.consume();
  }
        this.Devices= this.textfield2.getText();
        InDevices= Integer.parseInt(Devices);
        return InDevices;
 }
  //Method actionPerformed for textfield3
public String FileName (KeyEvent evt) {
        this.ReportName= this.textfield3.getText();
        return ReportName;
}

//method for generate menu
public void generateMenu(){
    menuBar = new JMenuBar();

    JMenu file = new JMenu("File");

    JMenuItem open = new JMenuItem("Open   ");
    open.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,Event.CTRL_MASK));

    JMenuItem exit = new JMenuItem("Exit   ");
    exit.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q,Event.CTRL_MASK));


    //Setings action for menu item
    //Call defined method
    open.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            openFile(evt);
        }
    });

    //Setings action for menu item
    //Call defined method
    exit.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            Quit(evt);
        }
    });


    file.add(open);
    file.add(exit);

    menuBar.add(file);
}
//Method for Open from menuFile 
private void openFile (ActionEvent evt) {
        PopUp Pop= new PopUp();
        Pop.Frame();
}

//Method for Exit from menuFile 
private void Quit (ActionEvent evt) {
        System.exit(0);
}




 public static void main(String[] args){
    System.setProperty("swing.defaultlaf", "com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            new GUI_project();
        }
    });
}

}

这是第二堂课:

public static int software;
public static String name;
public static void Company(){
GUI_project main= new GUI_project();
name=main.getSoftwareName();
if(name.equals("Microsoft")||name.equals("Norton")||name.equals("Oracle")||name.equals("CRM")){
    if(name.equals("Microsoft")){
        Name.software = 1200000;
    }else if(name.equals("Norton")){
        Name.software = 3000000;
    }else if(name.equals("Oracle")){
        Name.software = 1700000;
    }else if(name.equals("CRM")){
        Name.software = 2300000;
    }
  }else{
    System.out.println("Not a company, GOOD BYE!");
    System.exit(0);
}
}

我确信这是一个愚蠢的错误，但任何帮助都会很棒。一旦我能够让这两个类工作，其余的应该以同样的方式工作:)

Answer 1

尝试类似以下代码。

测试.java

import javax.swing.*;
import java.awt.*;
import javax.swing.event.*;

public class Test
{
    JFrame myMainWindow = new JFrame("This is my title");
    JPanel  firstPanel = new JPanel(null);
    JTextField textfield1 = new JTextField();

    public void runGUI() {
        myMainWindow.setBounds(10, 10, 500, 500);
        myMainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myMainWindow.setLayout(new GridLayout(1,1));
        createFirstPanel();
        myMainWindow.getContentPane().add(firstPanel);
        myMainWindow.setVisible(true);
    }

    public void createFirstPanel() {
        textfield1.setBounds(335,102,90,35);
        textfield1.setBackground(new Color(255,255,255));
        textfield1.setForeground(new Color(0,0,0));
        textfield1.setEnabled(true);
        textfield1.setFont(new Font("sansserif",0,12));
        textfield1.setVisible(true);
        textfield1.getDocument().addDocumentListener(new MyDocumentListener());
        firstPanel.add(textfield1);
    }

    private class MyDocumentListener implements DocumentListener {
        public void insertUpdate(DocumentEvent e) {
            new Class2(textfield1.getText());
        }

        public void removeUpdate(DocumentEvent e) {
            new Class2(textfield1.getText());
        }

        public void changedUpdate(DocumentEvent e) {}
    }

    public static void main(String[] args)
    {
        Test t = new Test();
        t.runGUI();
    }
}

Class2.java

public class Class2 {
    int software;

    public Class2(String s) {
        Company(s);
        System.out.println(s);
        System.out.println(software);
    }

    public void Company(String s) {
        if(s.equals("Microsoft")||s.equals("Norton")||s.equals("Oracle")||s.equals("CRM")){
            if(s.equals("Microsoft")) {
                software = 1200000;
                System.out.println("Matches Microsoft");
            } else if(s.equals("Norton")) {
                software = 3000000;
                System.out.println("Matches Norton");
            } else if(s.equals("Oracle")) {
                software = 1700000;
                System.out.println("Matches Oracle");
            } else if(s.equals("CRM")) {
                software = 2300000;
                System.out.println("Matches CRM");
            }
        } else {
            System.out.println("Not a company, GOOD BYE!");
        }
    }
}

我将 KeyAdapter 更改为 Document Listener，因为该事件在更好的时间触发，即在文档更改之后。而在您的版本中，KeyAdapter 在将字母放入 textfield1 之前触发事件。

编辑

如果你想让它在最后检查。删除 Document Listener 并在 Test.java 中添加以下代码

导入 javax.swing.; 导入java.awt。； 导入 javax.swing.event.; 导入 java.awt.event.;

public class Test
{
    JFrame myMainWindow = new JFrame("This is my title");
    JPanel  firstPanel = new JPanel(null);
    JTextField textfield1 = new JTextField();
    JButton button1 = new JButton("Check Company");

    public void runGUI() {
        myMainWindow.setBounds(10, 10, 500, 500);
        myMainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myMainWindow.setLayout(new GridLayout(1,1));
        createFirstPanel();
        myMainWindow.getContentPane().add(firstPanel);
        myMainWindow.setVisible(true);
    }

    public void createFirstPanel() {
        textfield1.setBounds(335,102,90,35);
        textfield1.setBackground(new Color(255,255,255));
        textfield1.setForeground(new Color(0,0,0));
        textfield1.setEnabled(true);
        textfield1.setFont(new Font("sansserif",0,12));
        textfield1.setVisible(true);
        firstPanel.add(textfield1);

        button1.setBounds(335,150,150,35);
        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                new Class2(textfield1.getText());
            }
        });
        firstPanel.add(button1);
    }

    public static void main(String[] args)
    {
        Test t = new Test();
        t.runGUI();
    }
}