我制作了JFrame并使用JLabel定义了背景图片。但是，一旦我放大JFrame，一切都会脱臼。如何构建我的JFrame以便它可以调整大小？
public class First extends javax.swing.JFrame {
/**
* Creates new form First
*/
public First() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton1 = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
t1 = new javax.swing.JTextField();
t2 = new javax.swing.JPasswordField();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
jLabel4 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("WELCOME");
getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
jButton1.setFont(new java.awt.Font("Segoe Script", 3, 24)); // NOI18N
jButton1.setText("LOGIN");
jButton1.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.RAISED));
jButton1.setContentAreaFilled(false);
jButton1.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
getContentPane().add(jButton1, new org.netbeans.lib.awtextra.AbsoluteConstraints(280, 310, 140, 30));
jLabel1.setFont(new java.awt.Font("Viner Hand ITC", 3, 36)); // NOI18N
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setText("Administrator of Library System");
getContentPane().add(jLabel1, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 30, 614, -1));
t1.setFont(new java.awt.Font("Segoe UI", 3, 20)); // NOI18N
t1.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.RAISED));
t1.setOpaque(false);
t1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
t1ActionPerformed(evt);
}
});
getContentPane().add(t1, new org.netbeans.lib.awtextra.AbsoluteConstraints(240, 200, 180, 30));
t2.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
t2.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.RAISED));
t2.setOpaque(false);
getContentPane().add(t2, new org.netbeans.lib.awtextra.AbsoluteConstraints(240, 250, 180, 30));
jLabel2.setFont(new java.awt.Font("Segoe Script", 3, 24)); // NOI18N
jLabel2.setText("Username -");
getContentPane().add(jLabel2, new org.netbeans.lib.awtextra.AbsoluteConstraints(30, 200, 200, 30));
jLabel3.setFont(new java.awt.Font("Segoe Script", 3, 24)); // NOI18N
jLabel3.setText("Password -");
getContentPane().add(jLabel3, new org.netbeans.lib.awtextra.AbsoluteConstraints(30, 250, 230, 30));
jButton2.setFont(new java.awt.Font("Segoe Script", 3, 24)); // NOI18N
jButton2.setText("Forgot Password ??");
jButton2.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.RAISED));
jButton2.setContentAreaFilled(false);
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
getContentPane().add(jButton2, new org.netbeans.lib.awtextra.AbsoluteConstraints(20, 410, 250, 40));
jLabel4.setIcon(new javax.swing.ImageIcon(getClass().getResource("/librarymanagementsystem/library_book.jpg"))); // NOI18N
jLabel4.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.LOWERED));
getContentPane().add(jLabel4, new org.netbeans.lib.awtextra.AbsoluteConstraints(-10, -10, 880, 500));
pack();
setLocationRelativeTo(null);
}// </editor-fold>
private void t1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try
{
Class.forName("java.sql.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "parin");
Statement stmt=con.createStatement();
String username="";
String password="";
String query="Select * from Liblogin;";
ResultSet rs=stmt.executeQuery(query);
while(rs.next())
{
username=rs.getString("username");
password=rs.getString("password");
}
rs.close();
stmt.close();
con.close();
String enteredUsername=t1.getText().toString();
String enteredPassword = new String(t2.getText());
if(enteredUsername.contentEquals(username)&&enteredPassword.contentEquals(password))
{
Homepage a=new Homepage();
a.setVisible(true);
this.dispose();
}
else
{
JOptionPane.showMessageDialog(this,"INVALID USER");
}
}
catch(Exception e)
{
JOptionPane.showMessageDialog(this, "ERROR IN CORRECTION");
}
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
this.dispose();
Security a=new Security();
a.setVisible(true);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(First.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(First.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(First.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(First.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new First().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JTextField t1;
private javax.swing.JPasswordField t2;
// End of variables declaration
}
答案 0 :(得分：0)
使用GridBagLayout作为布局管理员，花点时间查看组件的preferredSize，minimumSize和maximumSize属性。您还可以使用Box.Filler用于创建不可见组件的类，并在调整窗口大小时在JPanel中的组件之间添加它们。我无法帮助您，因为我不知道您对组件的确切要求是什么表现得像。我建议你阅读这本书Swing，第4章是给你的