السلام عليكم و رحمة الله و بركاته
إخواني/أخواتي الكرام :
يوجد لدي برنامج و لا أعرف عمل بعض الأكواد بها أتمنى أن تفيدوني بذالك :
الكود
package textfieldtest;
// Fig. 11.9: TextFieldFrame.java
// Demonstrating the JTextField class.
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;
public class TextFieldFrame extends JFrame
{
private JTextField textField1; // text field with set size
private JTextField textField2; // text field constructed with text
private JTextField textField3; // text field with text and size
private JPasswordField passwordField; // password field with text
// TextFieldFrame constructor adds JTextFields to JFrame
public TextFieldFrame()
{
super( "Testing JTextField and JPasswordField" );
setLayout( new FlowLayout() ); // set frame layout
// construct textfield with 10 columns
textField1 = new JTextField( 10 );
add( textField1 ); // add textField1 to JFrame
// construct textfield with default text
textField2 = new JTextField( "Enter text here" );
add( textField2 ); // add textField2 to JFrame
// construct textfield with default text and 21 columns
textField3 = new JTextField( "Uneditable text field", 16 );
textField3.setEditable( false ); // disable editing
add( textField3 ); // add textField3 to JFrame
// construct passwordfield with default text
passwordField = new JPasswordField( "Hidden text" );
add( passwordField ); // add passwordField to JFrame
// register event handlers
TextFieldHandler handler = new TextFieldHandler();
textField1.addActionListener( handler );
textField2.addActionListener( handler );
textField3.addActionListener( handler );
passwordField.addActionListener( handler );
} // end TextFieldFrame constructor
// private inner class for event handling
private class TextFieldHandler implements ActionListener
{
// process text field events
public void actionPerformed( ActionEvent event )
{
String string = ""; // declare string to display
// user pressed Enter in JTextField textField1
if ( event.getSource() == textField1 )
string = String.format( "textField1: %s",
event.getActionCommand() );
// user pressed Enter in JTextField textField2
else if ( event.getSource() == textField2 )
string = String.format( "textField2: %s",
event.getActionCommand() );
// user pressed Enter in JTextField textField3
else if ( event.getSource() == textField3 )
string = String.format( "textField3: %s",
event.getActionCommand() );
// user pressed Enter in JTextField passwordField
else if ( event.getSource() == passwordField )
string = String.format( "passwordField: %s",
new String( passwordField.getPassword() ) );
// display JTextField content
JOptionPane.showMessageDialog( null, string );
} // end method actionPerformed
} // end private inner class TextFieldHandler
} // end class TextFieldFrame
يا ريت شرح الأسطر التالية :
ما المقصود ب TextFieldHandler و ما عملها و شو بتفرق عن TextField ؟؟
TextFieldHandler handler = new TextFieldHandler();
ما وظيفة الكود هذا ؟
textField1.addActionListener( handler );
أخيراً ما وظيفة هذا الكود
if ( event.getSource() == textField1 )
string = String.format( "textField1: %s",
event.getActionCommand() );
خاصة
string = String.format( "textField1: %s",
و الكود
event.getActionCommand() );
أي ماذا يقصد ب ActionCommand ؟
و بارك الله فيكم
