phương pháp trong JComponent để quan sát tài sản borderPainted. bảo vệ PropertyChangeListener createActionChangeListener (JButton b) Một phương pháp tiện ích nội bộ tạo ra một người nghe thay đổi tài sản cá nhân cho một mục menu cụ thể. | Java Swing - O Reilly public JPasswordField Creates a new password field with zero columns. public JPasswordField String text Creates a new text field displaying the input text using the echo character . public JPasswordField int columns Creates a new text field with the requested number of columns. public JPasswordField String text int columns Creates a new text field with the specified number of columns displaying the input text using the echo character . public JPasswordField Document doc String text int columns This constructor called by all the others creates a new text field that uses the specified document model displays the specified string of text using the echo character and contains the requested number of columns. The echo character is set to by this constructor. Data Protection Methods public void cut public void copy These methods are overridden to disable cut and copy behavior in password fields. They simply call getTooikit .beep . If these methods were not overridden it would be possible for hidden passwords to be copied from password fields and pasted into nonhidden fields. public string getText int offs int len throws BadLocationException Defined in this class only for the purpose of being marked as deprecated. The getPassword method should be used instead. Miscellaneous Methods public boolean echoCharIsSet Indicates whether or not an echo character has been set. Note that a default echo character is defined so this method always returns true unless the echo character is explicitly set to u0000. The JTextArea Class The jTextArea class is modeled after AWT s TextArea providing much of the same functionality. Generally it is used to allow the user to enter a textual message or to display textual information to the user. Figure shows a JTextArea. - 595 - Java Swing - O Reilly Figure . JTextArea We CO about our da lự lives understand ng almost naming atthe world. C q c II Idle Ih ought in the math in eiy that .