Java GUI没有显示但没有错误

Question

我正在尝试让这个GUI显示并接受用户输入以在单独的类中执行计算，但是当我运行程序时它运行并说构建成功但没有任何反应。我想我需要创建一些类的实例，但我已经尝试将它放在多个位置，似乎没有任何工作。这是我的代码：

class infoGUI extends JFrame {

  private JButton btnOK  = new JButton("OK");
  private JButton btnCancel = new JButton("Cancel");

  private JTextField txtCustomerName = new JTextField();
  private JTextField txtCustomerNumber = new JTextField();
  private JTextField txtCreditLimit = new JTextField();
  private JTextField txtPrevBalance = new JTextField();
  private JTextField txtCurrentPurchases = new JTextField();
  private JTextField txtPayments = new JTextField();
  private JTextField txtCreditsReturns = new JTextField();
  private JTextField txtLatefeeds = new JTextField();


  private JLabel lblCustomerName = new JLabel("Name :");
  private JLabel lblCustomerNumber = new JLabel("Number :");
  private JLabel lblCreditLimit = new JLabel("Credit Limit :");
  private JLabel lblPrevbalance = new JLabel("Previous Balance :");
  private JLabel lblCurrentPurchases = new JLabel("Current Purchases :");
  private JLabel lblPayments = new JLabel("Payments :");
  private JLabel lblCreditsReturns = new JLabel("Credits/Returns :");
  private JLabel lblLateFees = new JLabel("Late Fees :");

  public infoGUI(){
    this.name = null;
    setTitle("Credit Wizard");
    setSize(300,375);
    setLayout(null);    
    setResizable(false);


    initComponent();
    initEvent();

  }
  private void initComponent(){
    btnOK.setBounds(20,300, 80,25);
    btnCancel.setBounds(110,300, 80,25);

    txtCustomerName.setBounds(100,10,100,20);
    txtCustomerNumber.setBounds(100,35,100,20);
    txtCreditLimit.setBounds(100,65,100,20);
    txtPrevBalance.setBounds(130,95,100,20);
    txtCurrentPurchases.setBounds(135,125,100,20);
    txtPayments.setBounds(100,155,100,20);
    txtCreditsReturns.setBounds(120,185,100,20);
    txtLatefeeds.setBounds(100,215,100,20);


    lblCustomerName.setBounds(20,10,100,20);
    lblCustomerNumber.setBounds(20,35,100,20);
    lblCreditLimit.setBounds(20,65,100,20);
    lblPrevbalance.setBounds(20,95,120,20);
    lblCurrentPurchases.setBounds(20,125,125,20);
    lblPayments.setBounds(20,155,100,20);
    lblCreditsReturns.setBounds(20,185,120,20);
    lblLateFees.setBounds(20,215,100,20);

    add(btnOK);
    add(btnCancel);

    add(lblCustomerName);
    add(lblCustomerNumber);
    add(lblCreditLimit);
    add(lblPrevbalance);
    add(lblCurrentPurchases);
    add(lblPayments);
    add(lblCreditsReturns);
    add(lblLateFees);

    add(txtCustomerName);
    add(txtCustomerNumber);
    add(txtCreditLimit);
    add(txtPrevBalance);
    add(txtCurrentPurchases);
    add(txtPayments);
    add(txtCreditsReturns);
    add(txtLatefeeds);
  }
  private void initEvent(){
    this.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e){
       System.exit(1);
      }
    });

    btnCancel.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        btnCancelClick(e);
      }
    });

    btnOK.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        btnOKClick(e);
      }
    });
  }

  private void btnCancelClick(ActionEvent evt){
    System.exit(0);
  } 
  private String name;
  private double custNum;
  private double creditLimit;
  private double prevBalance;
  private double currentPurchases;
  private double payments;
  private double creditsReturns;
  private double lateFees;
  private void btnOKClick(ActionEvent evt){

    try{
      String custName = (txtCustomerName.getText());
      setName(custName);
      custNum = Double.parseDouble(txtCustomerNumber.getText());
      setCustNum(custNum);
      creditLimit = Double.parseDouble(txtCreditLimit.getText());
      setCreditLimit(creditLimit);
      prevBalance = Double.parseDouble(txtPrevBalance.getText());
      setPrevBalance(prevBalance);
      currentPurchases = Double.parseDouble(txtPrevBalance.getText());
      setCurrentPurchases(currentPurchases);
      payments = Double.parseDouble(txtPayments.getText());
      setPayments(payments);
      creditsReturns = Double.parseDouble(txtCreditsReturns.getText());
      setCreditsReturns(creditsReturns);
      setLateFees(lateFees);
      System.exit(0);      
    }catch(Exception e){
      System.out.println(e);
      JOptionPane.showMessageDialog(null, 
          e.toString(),
          "Error", 
          JOptionPane.ERROR_MESSAGE);
    }
    }

   public void setName(String newName){  
    name = newName;

    }
   public String getName(){
       return name;
   }
   public void setCustNum(double newCustNum){  
    custNum = newCustNum;
   }
   public double getCustNum(){
       return custNum;
   }
   public void setCreditLimit(double newCreditLimit){  
    creditLimit = newCreditLimit;
    }
   public double getCreditLimit(){
       return creditLimit;
   }
   public void setPrevBalance(double newPrevBalance){  
    prevBalance = newPrevBalance;
    } 
   public double getPrevBalance(){
       return prevBalance;
   }
   public void setCurrentPurchases(double newCurrentPurchases){  
    currentPurchases = newCurrentPurchases;
    }
   public double getCurrentPurchases(){
       return currentPurchases;
   }
   public void setPayments(double newPayments){  
   payments = newPayments; 
    }
   public double getPayments(){
       return payments;
   }
   public void setCreditsReturns(double newCreditsReturns){
    creditsReturns = newCreditsReturns;
   }
    public double getCreditsReturns(){
       return creditsReturns;
   }
   public void setLateFees(double newLateFees){
    lateFees = newLateFees;
    }
   public double getLateFees(){
       return lateFees;
   }

感谢任何帮助

Answer 1

您必须使用main方法创建新的GUI。另外，在JFrame的构造函数末尾调用setVisible(true)：

public static void main(String[] args){
   new infoGUI(); // creates a new GUI 
}

和

  public infoGUI(){
    super(); 
    this.name = null;
    setTitle("Credit Wizard");
    setSize(300,375);
    setLayout(null);    
    setResizable(false);


    initComponent();
    initEvent();
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // good idea to put this in
    setVisible(true);
  }