我创建了一个按钮默认情况下，通过自定义代码不可见。 但现在我的问题是我不能让按钮可见！我想要的是，当用户LOG IN意味着LOG OUT按钮应该是可见的。 我怎么能用netbeans做到这一点？能帮助我吗？我是JAVA GUI的新手。我应该在这里添加什么条件？
JLabel j1;
public NewJFrame() {
initComponents();
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jButton4 = new javax.swing.JButton();
jLabel5 = new javax.swing.JLabel();
jLabel1 = new javax.swing.JLabel();
jComboBox1 = new javax.swing.JComboBox();
jButton1 = new javax.swing.JButton();
jTextField3 = new javax.swing.JTextField();
jButton2 = new javax.swing.JButton();
jPasswordField1 = new javax.swing.JPasswordField();
jButton3 = new javax.swing.JButton();
jButton5 = new javax.swing.JButton();
jLabel6 = new javax.swing.JLabel();
jComboBox2 = new javax.swing.JComboBox();
jLabel7 = new javax.swing.JLabel();
jLabel8 = new javax.swing.JLabel();
jTextField2 = new javax.swing.JTextField();
jComboBox3 = new javax.swing.JComboBox();
jLabel9 = new javax.swing.JLabel();
jLabel10 = new javax.swing.JLabel();
jButton6 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel2.setFont(new java.awt.Font("Segoe UI", 1, 24)); // NOI18N
jLabel2.setForeground(new java.awt.Color(102, 255, 0));
jLabel2.setText("EMAIL");
jLabel3.setFont(new java.awt.Font("Segoe UI", 1, 24)); // NOI18N
jLabel3.setForeground(new java.awt.Color(102, 255, 0));
jLabel3.setText("PASSWORD");
jTextField1.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(255, 0, 153), 2, true));
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jButton4.setBackground(new java.awt.Color(0, 153, 255));
jButton4.setFont(new java.awt.Font("Times New Roman", 1, 36)); // NOI18N
jButton4.setText("Log In");
jButton4.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED), javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(0, 153, 255), null, null)));
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton4ActionPerformed(evt);
}
});
jLabel5.setBackground(new java.awt.Color(255, 153, 102));
jLabel5.setFont(new java.awt.Font("Rockwell Extra Bold", 3, 24)); // NOI18N
jLabel5.setForeground(new java.awt.Color(255, 0, 204));
jLabel5.setText("SELECT TYPE");
jLabel1.setBackground(new java.awt.Color(153, 102, 255));
jLabel1.setFont(new java.awt.Font("Bookman Old Style", 3, 48)); // NOI18N
jLabel1.setForeground(new java.awt.Color(255, 0, 204));
jLabel1.setText("SHOPPERS BAY...");
jLabel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(255, 102, 102), new java.awt.Color(255, 255, 102), null));
jLabel1.setIconTextGap(2);
jComboBox1.setFont(new java.awt.Font("Times New Roman", 1, 18)); // NOI18N
jComboBox1.setForeground(new java.awt.Color(0, 0, 51));
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "CLOTHES", "ACCESSORIES", "SHOES" }));
jComboBox1.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createCompoundBorder(), javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED)));
jButton1.setBackground(new java.awt.Color(0, 153, 255));
jButton1.setFont(new java.awt.Font("Times New Roman", 1, 24)); // NOI18N
jButton1.setText("OK");
jButton1.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED), javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, new java.awt.Color(0, 153, 255), new java.awt.Color(0, 153, 255), null, null)));
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jTextField3.setForeground(new java.awt.Color(153, 153, 153));
jTextField3.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(255, 0, 255), 1, true));
jTextField3.setDisabledTextColor(new java.awt.Color(0, 0, 0));
jTextField3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField3ActionPerformed(evt);
}
});
jButton2.setBackground(new java.awt.Color(255, 51, 51));
jButton2.setFont(new java.awt.Font("Times New Roman", 1, 14)); // NOI18N
jButton2.setText("SEARCH");
jButton2.setBorder(javax.swing.BorderFactory.createCompoundBorder(null, javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED)));
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jPasswordField1.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(255, 0, 153), 2, true));
jButton3.setBackground(new java.awt.Color(0, 153, 255));
jButton3.setFont(new java.awt.Font("Times New Roman", 1, 36)); // NOI18N
jButton3.setText("Register");
jButton3.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED), javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(0, 153, 255), null, null)));
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jButton5.setFont(new java.awt.Font("Stencil", 3, 14)); // NOI18N
jButton5.setForeground(new java.awt.Color(204, 0, 0));
jButton5.setText("ACCOUNTS");
jButton5.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(102, 204, 0), null, new java.awt.Color(102, 51, 0)));
jButton5.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton5ActionPerformed(evt);
}
});
jLabel6.setFont(new java.awt.Font("Tahoma", 3, 24)); // NOI18N
jLabel6.setForeground(new java.awt.Color(255, 0, 204));
jLabel6.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel6.setText("New User?");
jComboBox2.setFont(new java.awt.Font("Times New Roman", 1, 18)); // NOI18N
jComboBox2.setForeground(new java.awt.Color(0, 0, 51));
jComboBox2.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "VISITOR", "ACCOUNTANT", "ADMINISTRATOR" }));
jComboBox2.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(102, 255, 0), null, null));
jComboBox2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jComboBox2ActionPerformed(evt);
}
});
jLabel7.setFont(new java.awt.Font("SimSun-ExtB", 1, 11)); // NOI18N
jLabel7.setForeground(new java.awt.Color(102, 255, 0));
jLabel7.setText("PRICE:");
jLabel8.setText("to");
jTextField2.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(255, 0, 255), 1, true));
jComboBox3.setBackground(new java.awt.Color(255, 204, 204));
jComboBox3.setFont(new java.awt.Font("Stencil", 1, 12)); // NOI18N
jComboBox3.setForeground(new java.awt.Color(51, 51, 255));
jComboBox3.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "CLOTHES", "ACCESSORIES", "SHOES" }));
jComboBox3.setBorder(javax.swing.BorderFactory.createMatteBorder(1, 1, 1, 1, new java.awt.Color(255, 0, 204)));
jLabel9.setFont(new java.awt.Font("SimSun-ExtB", 1, 12)); // NOI18N
jLabel9.setForeground(new java.awt.Color(102, 255, 0));
jLabel9.setText("CATEGORY:");
jLabel10.setIcon(new javax.swing.ImageIcon(getClass().getResource("/finalproject/Collages - Copy1.png"))); // NOI18N
jButton6.setText("LOGOUT");
jButton6.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton6ActionPerformed(evt);
}
});
jButton6.setVisible(false);
if(jComboBox2.getSelectedItem()=="ADMINISTRATOR")
jButton6.setVisible(true);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(30, 30, 30)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addGroup(layout.createSequentialGroup()
.addGap(59, 59, 59)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 209, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(69, 69, 69)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(107, 107, 107)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 62, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jButton6, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 131, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(58, 58, 58)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel9, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jComboBox3, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel7, javax.swing.GroupLayout.PREFERRED_SIZE, 61, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, 78, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(4, 4, 4)
.addComponent(jLabel8, javax.swing.GroupLayout.PREFERRED_SIZE, 12, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(10, 10, 10)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, 79, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(10, 10, 10)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(79, 79, 79)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 153, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel6, javax.swing.GroupLayout.PREFERRED_SIZE, 136, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 139, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jButton5, javax.swing.GroupLayout.PREFERRED_SIZE, 8, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(184, 184, 184))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jComboBox2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(168, 168, 168))))))
.addComponent(jLabel10))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel3)
.addComponent(jLabel2))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 240, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, 240, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(67, 67, 67))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(33, 33, 33)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel9)
.addGap(14, 14, 14)
.addComponent(jComboBox3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(1, 1, 1)
.addComponent(jLabel7)
.addGap(14, 14, 14)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addComponent(jLabel8))
.addGroup(layout.createSequentialGroup()
.addGap(27, 27, 27)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(24, 24, 24)
.addComponent(jButton2)))
.addGap(33, 33, 33))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)))
.addComponent(jLabel10, javax.swing.GroupLayout.PREFERRED_SIZE, 193, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(3, 3, 3)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3)))
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 44, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(20, 20, 20)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(80, 80, 80))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jComboBox2, javax.swing.GroupLayout.PREFERRED_SIZE, 33, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 45, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 45, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addGap(7, 7, 7)
.addComponent(jLabel6, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 43, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addComponent(jButton6, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGap(48, 48, 48)))
.addComponent(jButton5))
);
pack();
}// </editor-fold>
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
Connection conn=null;
try{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ex) {
Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
}
conn =DriverManager.getConnection(DB_URL, USER, PASS);
Statement stmt=conn.createStatement();
String S1 = jTextField1.getText();
String S2 = jPasswordField1.getText().toString();
String S3=jComboBox2.getSelectedItem().toString();
// System.out.println("User: "+userName + " Password: "+ passWord);
// if user name is blank, warning message shown
if(S1.isEmpty() || S1 == null){
JOptionPane.showMessageDialog(null, "Please insert a valid user name", "Warning", JOptionPane.WARNING_MESSAGE);
return;
}
// if password is blank, warning message shown
if(S2.isEmpty() || S2 == null){
JOptionPane.showMessageDialog(null, "Password field is empty", "Warning", JOptionPane.WARNING_MESSAGE);
return;
}
int flag=0;
String sql;
sql="SELECT * from member where EMAIL='"+S1+"'";
ResultSet rs=stmt.executeQuery(sql);
//System.out.println(rs.next());
String uname="",pw="",category="";
while(rs.next()){
uname=rs.getString("EMAIL");
pw=rs.getString("PASSWORD");
category=rs.getString("CATEGORY");
if(uname.matches(S1) && pw.equals(S2)==true && category.matches(S3))
{
flag=1;
/*setVisible(false);
Congrats J7=new Congrats();
J7.getContentPane().setBackground(Color.green);
J7.setVisible(true); */
if(jComboBox2.getSelectedItem()=="VISITOR")
{
setVisible(false);
NewJFrame f1=new NewJFrame();
f1.setVisible(true);
jButton6.setVisible(true);
}
else if(jComboBox2.getSelectedItem()=="ACCOUNTANT")
{
setVisible(false);
inter4 f=new inter4();
f.setVisible(true);
}
else if(jComboBox2.getSelectedItem()=="ADMINISTRATOR")
{
setVisible(false);
NewJFrame f1=new NewJFrame();
f1.setVisible(true);
}
}
}
if(flag==0)
JOptionPane.showMessageDialog(null,"login failed");
stmt.close();
conn.close();
}
catch(SQLException ss){
ss.printStackTrace();
}
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
setVisible(false);
NewJFrame21 fF=new NewJFrame21();
fF.getContentPane().setBackground(Color.magenta);
fF.setVisible(true);
}
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
setVisible(false);
inter4 J1=new inter4();
J1.getContentPane().setBackground(Color.green);
J1.setVisible(true);
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JButton jButton5;
private javax.swing.JButton jButton6;
private javax.swing.JComboBox jComboBox1;
private javax.swing.JComboBox jComboBox2;
private javax.swing.JComboBox jComboBox3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel10;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JPasswordField jPasswordField1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
private javax.swing.JTextField jTextField3;
// End of variables declaration
private ImageIcon format=null;
}
答案 0 :(得分：0)
在Java GUI中成为新手我相信最好手工编写一些GUI代码，只是为了看看它是如何工作的。当您了解swing的概念时，您可以转到GUI设计器，以便更轻松，更快速地完成任务。但是，如果没有（深入）了解事件处理，布局管理器等事情，您无法确定“如何”实现您想要实现的内容（并使其显示在屏幕上并进行交互）
所以你想要的是当你按下另一个按钮（LOG IN一个按钮）时按钮变得可见。 这必须通过ActionListener到LOG IN按钮来完成。因此，您必须向编译器声明此类将具有一些操作事件（“操作”事件是按钮单击的情况，“键”事件是按下键的情况等）。
所以你写了你的班级定义：
class GUIExample implements ActionListener{
现在您可以定义按钮（我将定义其中的几个）。 注意：总是将按钮（和其他组件）名称声明为类字段（不在实例化它们的方法中），因此您可以在所有类方法中引用它们。
JButton logIn, logOut;
JFrame frame; //the application main frame
应该这样做！ 现在让我们做一个构造函数！
GUIExample(){
frame = new JFrame("GUI Example in Swing"); //frame's head text
logIn = new JButton("LOG IN");
logOut = new JButton("LOG OUT");
frame.setSize(300,400);
frame.setVisible(true);
frame.add(logIn);
logIn.setVisible(true);
frame.add(logOut);
logOut.setVisible(false); //The LOG OUT is invisible now!
logIn.addActionListener(this); //this tells the JVM to keep an eye on this
// button and run the actionPerformed method
// if it gets pushed!
}
现在，如果按下LOG IN按钮，你必须告诉JVM“做什么”！
public void actionPerformed(ActionEvent e){
JButton src = (JButton) e.getSource() //get the objectthat triggered the event
if (src.equals(logIn)) //if the source is the LOG IN button (in our case it is the only thing that can trigger an event)
logOut.setVisible(true); ///finally! make the LOG OUT visible!
}
应该这样做！现在通过main调用构造函数：
public static void main (String args[]){
new GUIExample();
}
就是这样！要运行此示例，请不要忘记导入Swing：
import javax.swing.*;
和事件包：
import java.awt.event.*;
希望我帮忙！