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- LẬP 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 OK
JButton 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 Here"
JTextField txtName = new JTextField("Type Name Here");
// Create a check box with text bold
JCheckBox chkBold = new JCheckBox("Bold");
// Create a radio button with text red
JRadioButton rbRed = new JRadioButton("Red");
// Create a combo box with choices red, green, blue
JComboBox 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.
JTextArea(Document doc, String text, int rows, int
columns)
- JTextArea
Common methods
void append(String str)
Append the given text to the end of the document.
void insert(String str, int pos)
Insert the specified text at the given position . To insert text
at the beginning of the document, use a position of 0.
void replaceRange(String str, int start, int
end)
Replace a section of the document
- JTextArea
public int getLineStartOffset(int line)
throws BadLocationException
Return the character offset (from the beginning) that marks
the beginning of the specified line number.
public int getLineEndOffset(int line) throws
BadLocationException
Return the character offset (from the beginning) that marks
the end of the specified line number. This is actually the
offset of the first character of the next line.
public int getLineOfOffset(int offset) throws
BadLocationException
Return the line number that contains the given character
offset (from the beginning of the document).
- JTextArea
JPanel contentPane = new JPanel();
JLabel lblNewLabel = new JLabel("Nhập dữ liệu:");
contentPane.add(lblNewLabel);
JTextArea textArea = new JTextArea(3,15);
textArea.setWrapStyleWord(true);
textArea.setLineWrap(true);
JScrollPane scrollPane = new JScrollPane(textArea);
contentPane.add(scrollPane);
- class MyJTextArea extends JFrame {
private JPanel contentPane;
JTextArea
public MyJTextArea() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 257, 128);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
JLabel lblNewLabel = new JLabel("Nhập dữ liệu:");
contentPane.add(lblNewLabel);
JScrollPane scrollPane = new JScrollPane();
JTextArea textArea = new JTextArea(3,15);
textArea.setWrapStyleWord(true);
textArea.setLineWrap(true);
scrollPane.setViewportView(textArea);
contentPane.add(scrollPane);
}
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