Bài giảng Lập trình Cơ sở dữ liệu – Java: Bài 3.1 - Nguyễn Hữu Thể

Bài giảng Lập trình cơ sở dữ liệu Java - Bài 3: Components. Chương này cung cấp cho người học các nội dung: JTable, JButton, JMenu, JTextField, JToolBar, JCheckBox, JOptionPane, JRadioButton, JFileChooser, JPanelJComboBox, JList. Mời các bạn cùng tham khảo nội dung chi tiết.
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Bài giảng Lập trình Cơ sở dữ liệu – Java: Bài 3.1 - Nguyễn Hữu ThểLẬP TRÌNH JAVA CSDL BÀI 3 COMPONENTS Nguyễn Hữu Thể 1 Nội dung JLabel  JTable JButton  JMenu JTextField  JToolBar JCheckBox  JOptionPane JRadioButton  JFileChooser JPanel JComboBox, JList 2 GUI Components JButton, JLabel, JTextField, JCheckBox, JRadioButton, and JComboBox. Each GUI component class provides several constructors that you can use to create GUI component objects. 3 GUI Components// Create a button with text OKJButton btOK = new JButton(OK); // Create a label with text Enter your name: JLabel lbName = new JLabel(Enter your name: );// Create a text field with text Type Name HereJTextField txtName = new JTextField(Type Name Here);// Create a check box with text boldJCheckBox chkBold = new JCheckBox(Bold);// Create a radio button with text redJRadioButton rbRed = new JRadioButton(Red);// Create a combo box with choices red, green, blueJComboBox cboColor = new JComboBox(new String[]{Red,Green, Blue}); 4 Working with Components javax.swing.Jcomponent Several methods:  setEnabled(boolean): receive user input (an argument of true) or is inactive and cannot receive input (false). Components are enabled by default.  isEnabled() returns a boolean value.  setVisible(boolean): for all components. Use true to display a component and false to hide it.  isVisible()  setSize(int, int): width and height specified as arguments  setSize(Dimension) uses a Dimension  getSize(): returns a Dimension object with height and width 5 Working with Components setText() getText() setValue() and getValue() for components that store a numeric value. 6 JLabel Display Text, not editable Constructor: Label() : An empty label JLabel(String) : A label with the specified text JLabel(String, int) : A label with the specified text and alignment LEFT, CENTER, and RIGHT. JLabel(String, Icon, int) : A label with the specified text, icon, and Alignment 7 JLabelCommon Methods: void setFont (Font f) void setText(String S) String getText() void setIcon(Icon) 8 JLabel Example: JLabel lbl=new JLabel(Họ và tên:); JLabel lbl=new JLabel(Ngày sinh:); 9 JLabel The use of HTML is supported by most Swing components. Example: use HTML markup to create multiline and multifont labels: JLabel lbHoten = new JLabel(Dòng 1Dòng 2); 10 JTextField Display data, Input data Constructors JTextField(): An empty text field JTextField(int): A text field with the specified width JTextField(String): A text field with text JTextField(String, int): A text field with the specified text and width Common Methods void setText(String S) String getText() void setEditable(boolean b) boolean isEditable() JTextField Example setLayout(new FlowLayout()); JLabel lbHoten = new JLabel(Nhập họ và tên); add(lbHoten); JTextField txtHoten = new JTextField(20); add(txtHoten); JTextField Don’t allow input data txtHoten.setEditable(false) To set Text in code behind for JTextField txtHoten.setText(Hello world); To get Text from JTextField String s = txtHoten.getText(); We could convert data int n = Integer.parseInt(s); //s is String double d = Double.parseDouble(s); float f = Float.parseFloat(s); To set focus: txtHoten.requestFocus(); JPasswordField Hide the characters a user is typing into the field. JPasswordField class, a subclass of JTextField. JPasswordField constructor methods take the same arguments as those of its parent class. Methods:  JPasswordField(String text, int columns)  char[] getPassword(): returns the text contained in this password field JPasswordField setEchoChar(char): replacing each input character with the specified character JPasswordField pass = new JPasswordField(20); pass.setEchoChar(#); JTextArea Input is more than one line long Constructors JTextArea(): Create a default text area. JTextArea(int rows, int columns): Create a text area with the specified number of rows and columns. JTextArea(String text) JTextArea(String text, int rows, int columns) JTextArea(Document doc): Create a text area that uses the specified Document. ...