Uvod v JButton na Javi
Razred JButton v Javi se uporablja za ustvarjanje gumbov, s katerimi lahko izvajate kateri koli ActionEvent, kadar ga kliknemo. Da bi dosegli dejanje dogodka, je treba implementirati vmesnik ActionListener. Komponenta gumbov v Swingu je podobna kot komponenta gumba AWT, le da lahko vsebuje besedilo, sliko ali oboje. Razred JButton razširja razred JComponent in ga je mogoče uporabiti v posodi.
Izjava o razredu JButton
Izjava razreda javax.swing.JButton je spodaj:
public class JButton extends AbstractButton implements Accessible
Vrste konstruktorjev, ki se uporabljajo v razredu JButton
Obstaja pet vrst konstruktorjev, ki se v osnovi uporabljajo v razredu JButton:
1. JButton ()
Ta konstruktor bo ustvaril gumb v komponenti brez ikone ali besedila.
Primer
import java.awt.*;
import javax.swing.*;
public class JButtonExample (
public static void main(String() args) (
JFrame frame=new JFrame("Button Example");
JButton b=new JButton();
b.setPreferredSize(new Dimension(100, 30));
frame.add(b);
frame.setSize(500, 500);
frame.setLayout(new FlowLayout());
frame.setVisible(true);
)
)
Izhod:
2. JButton (String text)
Ta konstruktor bo ustvaril gumb v komponenti z navedenim besedilom v parametrih.
Primer
import java.awt.*;
import javax.swing.*;
public class JButtonExample (
public static void main(String() args) (
JFrame frame=new JFrame("Button Example");
JButton b=new JButton("Click Here");
b.setPreferredSize(new Dimension(100, 30));
frame.add(b);
frame.setSize(500, 500);
frame.setLayout(new FlowLayout());
frame.setVisible(true);
)
)
Izhod:
3. JButton (ikona img)
Ta konstruktor bo ustvaril gumb v komponenti s sliko img, navedeno v parametrih.
Primer
import java.awt.*;
import javax.swing.*;
public class JButtonExample (
public static void main(String() args) (
JFrame frame=new JFrame("Button Example");
JButton b=new JButton(new ImageIcon("C:\\custom.png.webp"));
frame.add(b);
frame.setSize(500, 500);
frame.setLayout(new FlowLayout());
frame.setVisible(true);
)
)
Izhod:
4. JButton (akcija a)
Ta konstruktor bo ustvaril gumb v komponenti z lastnostmi, ki jih v parametru Action a.
Primer
importawt.*;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class JButtonExample extends JFrame(
private JButton reg;
private Action action = new buttonAction();
public JButtonExample() (
super("JButton Demo example");
setLayout(new FlowLayout());
reg = new JButton(action);
reg.setPreferredSize(new Dimension(100, 30));
add(reg);
)
public class buttonAction extends AbstractAction(
public void actionPerformed(ActionEvent e)
(
JOptionPane.showMessageDialog(null, "Button click");
)
)
public static void main(String() args) (
JButtonExample jb = new JButtonExample();
jb.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jb.setSize(300, 300);
jb.setVisible(true);
)
)
Izhod:
5. JButton (String text, ikona img)
Ta konstruktor bo ustvaril gumb v komponenti z besedilom in določeno sliko v parametrih.
Primer
import java.awt.*;
import javax.swing.*;
public class JButtonExample (
public static void main(String() args) (
JFrame frame=new JFrame("Button Example");
JButton b=new JButton("Click here", new ImageIcon("C:\\custom.png.webp"));
frame.add(b);
frame.setSize(500, 500);
frame.setLayout(new FlowLayout());
frame.setVisible(true);
)
)
Izhod:
Metode razreda JButton
Spodaj so najpogosteje uporabljene metode v razredu JButton:
- Neveljaven setText (besedilo niza): Ta metoda se v osnovi uporablja za nastavitev navedenega besedila na gumbu v komponenti.
- String gettext (): Ta metoda se uporablja za vrnitev besedilo gumba v določenem komponento.
- Void setEnabled (boolean b): Ta metoda se uporablja za omogočanje ali onemogočanje gumba s prenosom ustrezne vrednosti v parametru.
- Neveljaven setIcon (ikona i): Ta metoda se uporablja za nastavitev določene ikone "I" na gumb.
- Ikona getIcon (): Ta metoda se uporablja za vrnitev ikone določenega gumba.
- Void setHorizontalTextPosition (int hpos): Ta metoda se uporablja za nastavitev vodoravnega položaja sporočila gumba glede na njegovo ikono.
- Neveljaven stVerticalTextPosition (int vpos): Ta metoda se uporablja za nastavitev navpičnega položaja sporočila gumba glede na njegovo ikono.
Primer razreda JButton
Spodaj je primer razreda JButton:
Operacija CRUD na JTable
package jbuttonapplication;
import javax.swing.table.DefaultTableModel;
public class NewJFrame extends javax.swing.JFrame (
public NewJFrame() (
initComponents();
)
private void initComponents() (
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
rno = new javax.swing.JTextField();
fname = new javax.swing.JTextField();
lname = new javax.swing.JTextField();
add = new javax.swing.JTextField();
jScrollPane1 = new javax.swing.JScrollPane();
jbtable = new javax.swing.JTable();
jbnew = new javax.swing.JButton();
jbadd = new javax.swing.JButton();
jbupdate = new javax.swing.JButton();
jbdelete = new javax.swing.JButton();
label = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("Roll No");
jLabel2.setText("First Name");
jLabel3.setText("Last Name");
jLabel4.setText("Address");
jbtable.setModel(new javax.swing.table.DefaultTableModel(
new Object ()() (
),
new String () (
"Roll No", "First Name", "Last Name", "Address"
)
) (
Class() types = new Class () (
java.lang.Integer.class, java.lang.String.class, java.lang.String.class, java.lang.String.class
);
public Class getColumnClass(int columnIndex) (
return types (columnIndex);
)
));
jbtable.addMouseListener(new java.awt.event.MouseAdapter() (
public void mouseClicked(java.awt.event.MouseEvent evt) (
jbtableMouseClicked(evt);
)
));
jScrollPane1.setViewportView(jbtable);
jbnew.setText("New");
jbnew.addActionListener(new java.awt.event.ActionListener() (
public void actionPerformed(java.awt.event.ActionEvent evt) (
jbnewActionPerformed(evt);
)
));
jbadd.setText("Add");
jbadd.addActionListener(new java.awt.event.ActionListener() (
public void actionPerformed(java.awt.event.ActionEvent evt) (
jbaddActionPerformed(evt);
)
));
jbupdate.setText("Update");
jbupdate.addActionListener(new java.awt.event.ActionListener() (
public void actionPerformed(java.awt.event.ActionEvent evt) (
jbupdateActionPerformed(evt);
)
));
jbdelete.setText("Delete");
jbdelete.addActionListener(new java.awt.event.ActionListener() (
public void actionPerformed(java.awt.event.ActionEvent evt) (
jbdeleteActionPerformed(evt);
)
));
label.setForeground(new java.awt.Color(204, 0, 0));
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(136, 136, 136)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel2)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel4)
.addComponent(jLabel3)
.addComponent(jbnew))))
.addGap(37, 37, 37)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(rno, javax.swing.GroupLayout.DEFAULT_SIZE, 200, Short.MAX_VALUE)
.addComponent(fname)
.addComponent(lname)
.addComponent(add))
.addGap(32, 32, 32)
.addComponent(label, javax.swing.GroupLayout.PREFERRED_SIZE, 375, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jbadd)
.addGap(46, 46, 46)
.addComponent(jbupdate)
.addGap(74, 74, 74)
.addComponent(jbdelete))))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(2, 2, 2)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(177, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(117, 117, 117)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(rno, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(label))
.addComponent(jLabel1))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(fname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(lname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel4)
.addComponent(add, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(46, 46, 46)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jbnew)
.addComponent(jbadd)
.addComponent(jbupdate)
.addComponent(jbdelete))
.addGap(52, 52, 52)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 130, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(328, Short.MAX_VALUE))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
pack();
)
private void jbnewActionPerformed(java.awt.event.ActionEvent evt) (
rno.setText("");
fname.setText("");
lname.setText("");
add.setText("");
)
private void jbaddActionPerformed(java.awt.event.ActionEvent evt) (
label.setText("");
DefaultTableModel model = (DefaultTableModel)jbtable.getModel();
if(!rno.getText().isEmpty()&&!fname.getText().isEmpty()
&&!lname.getText().isEmpty()&&!add.getText().isEmpty())
(
model.addRow(new Object()(rno.getText().trim(), fname.getText().trim(),
lname.getText().trim(), add.getText().trim()));
)
else
(
label.setText("All the fields should be filled");
)
)
private void jbtableMouseClicked(java.awt.event.MouseEvent evt) (
DefaultTableModel model = (DefaultTableModel)jbtable.getModel();
rno.setText(model.getValueAt(jbtable.getSelectedRow(), 0).toString());
fname.setText(model.getValueAt(jbtable.getSelectedRow(), 1).toString());
lname.setText(model.getValueAt(jbtable.getSelectedRow(), 2).toString());
add.setText(model.getValueAt(jbtable.getSelectedRow(), 3).toString());
)
private void jbupdateActionPerformed(java.awt.event.ActionEvent evt) (
label.setText("");
DefaultTableModel model = (DefaultTableModel)jbtable.getModel();
if(jbtable.getSelectedRow()==-1)
(
if(jbtable.getRowCount()==0)
(
label.setText("Table is Empty");
)
else
(
label.setText("No Row Selected to Update");
)
)
else
(
model.setValueAt(rno.getText(), jbtable.getSelectedRow(), 0);
model.setValueAt(fname.getText(), jbtable.getSelectedRow(), 1);
model.setValueAt(lname.getText(), jbtable.getSelectedRow(), 2);
model.setValueAt(add.getText(), jbtable.getSelectedRow(), 3);
)
)
private void jbdeleteActionPerformed(java.awt.event.ActionEvent evt) (
label.setText("");
DefaultTableModel model = (DefaultTableModel)jbtable.getModel();
if(jbtable.getSelectedRow()==-1)
(
if(jbtable.getRowCount()==0)
(
label.setText("Table is Empty");
)
else
(
label.setText("No Row Selected to Update");
)
)
else
(
model.removeRow(jbtable.getSelectedRow());
)
)
public static void main(String args()) (
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(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
) catch (InstantiationException ex) (
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
) catch (IllegalAccessException ex) (
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
) catch (javax.swing.UnsupportedLookAndFeelException ex) (
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
)
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() (
public void run() (
new NewJFrame().setVisible(true);
)
));
)
// Variables declaration - do not modify
private javax.swing.JTextField add;
private javax.swing.JTextField fname;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JButton jbadd;
private javax.swing.JButton jbdelete;
private javax.swing.JButton jbnew;
private javax.swing.JTable jbtable;
private javax.swing.JButton jbupdate;
private javax.swing.JLabel label;
private javax.swing.JTextField lname;
private javax.swing.JTextField rno;
// End of variables declaration
)
Izhod:
Sklepi - JButton v Javi
Razred JButton lahko uporabimo za ustvarjanje komponente gumba za izvajanje sprememb komponente na dinamičen način, kot je zgornji primer.
Priporočeni članki
To je vodnik za JButton na Javi. Tukaj razpravljamo o vrstah konstruktorjev, ki se uporabljajo v razredu JButton, skupaj z metodami in primerom. Če želite izvedeti več, lahko preberete tudi druge naše predlagane članke -
- JTextField v Javi
- JDialog na Javi
- BorderLayout na Javi
- Različica kartic na Javi
- JPanel v Javi (Konstruktorji)
- Skupinska postavitev na Javi
- Primeri JFrame v Javi
- JLabel v Javi
- Celoten vodnik za pretok v Javi
- Metode in program JTable v Javi