Java编程

java窗口教程,java扫雷教程

init()方法:程序片第一次被创建,初次运行初始化程序片时调用。

stop()方法:每次程序片从web浏览器的视线中离开时调用,时程序片能关闭代价高昂的操作;同样在调用destroy()前调用。

destroy()方法:程序片不再需要,将它从页面中卸载时调用。

start()方法:每当程序片进入web浏览器中,并且允许程序片启动他的常规操作时调用(特殊的程序片被stop()关闭);同样在init()后调用。

paint()方法:基础类Component的一部分(继承结构中上朔三级)。作为update()的一部分调用,以便对程序片的画布进行特殊的描绘。

2.事件模型:(1)先在类中添加addXXXXXListener()方法。

(2)重写执行接口的方法。

package thirteen;import java.awt.*;import java.awt.event.*;import java.applet.*;public class Button2New extends Applet {Button b1 = new Button(“button1”), b2 = new Button(“button2”);public void init() {b1.addActionListener(new B1());b2.addActionListener(new B2());add(b1);add(b2);}class B1 implements ActionListener {public void actionPerformed(ActionEvent e) {getAppletContext().showStatus(“BUTTon1”);}}class B2 implements ActionListener {public void actionPerformed(ActionEvent e) {getAppletContext().showStatus(“Button2”);}}}3.制作窗口:(1)main()方法中新建一个Frame类,并将applet的衍生类给其初始化。

(2)继承WindowAdapter类,并重写windowClosing()方法。

(3)执行Frame的setVisible()方法。

package thirteen;import java.applet.*;import java.applet.*;import java.awt.BorderLayout;import java.awt.Button;import java.awt.TextField;import java.awt.Desktop.Action;import java.awt.Frame;import java.awt.event.*;import java.time.temporal.TemporalQueries;import javax.swing.table.TableRowSorter;import org.omg.CORBA.FloatSeqHelper;public class TextNew extends Applet {Button b1 = new Button(“Get Text”), b2 = new Button(“Set Text”);TextField t1 = new TextField(30), t2 = new TextField(30), t3 = new TextField(30);String s = new String();public void init() {b1.addActionListener(new B1());b2.addActionListener(new B2());t1.addTextListener(new T1());t1.addActionListener(new T1A());t1.addKeyListener(new T1K());add(b1);add(b2);add(t1);add(t2);add(t3);}class T1 implements TextListener {public void textValueChanged(TextEvent e) {t2.setText(t1.getText());}}class T1A implements ActionListener {private int count = 0;@Overridepublic void actionPerformed(ActionEvent e) {// TODO 自动生成的方法存根t3.setText(“t1 Action Event ” + count++);}}class T1K extends KeyAdapter {public void keyTyped(KeyEvent e) {String tString = t1.getText();if (e.getKeyChar() == KeyEvent.VK_BACK_SPACE) {if (tString.length() > 0) {tString = tString.substring(0, tString.length() – 1);t1.setText(tString);}}elset1.setText(t1.getText()+Character.toUpperCase(e.getKeyChar()));t1.setCaretPosition(t1.getText().length());e.consume();}} class B1 implements ActionListener{public void actionPerformed(ActionEvent e){s=t1.getSelectedText();if(s.length()==0)s=t1.getText();t1.setEditable(true);}}class B2 implements ActionListener{public void actionPerformed(ActionEvent e){t1.setText(“Insert by Button2:”+s);t1.setEditable(false);;}} public static void main(String[] args){TextNew applet=new TextNew();Frame aFrame=new Frame(“TextNew”);aFrame.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e){System.exit(0);}});aFrame.add(applet, BorderLayout.CENTER);aFrame.setSize(300,200);applet.init();applet.start();aFrame.setVisible(true);}}4.JavaBean要求:

(1)所有的类必须放在一个包中,在web中没有包是不存在的。

(2)所有的类必须声明为public class,这样才能够被外部访问。

(3)类中所有的属性都必须封装,使用private声明。

(4)封装的属性如果需要被外部所操作,则必须编写对应的setter,getter方法。

(5)一个JavaBean中至少存在一个无参构造方法。

5.Swing各种边框的一个例子:

package thirteen;import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.border.*;public class Borders extends JPanel {static JPanel showBorder(Border b) {JPanel jPanel = new JPanel();jPanel.setLayout(new BorderLayout());String nm = b.getClass().toString();nm = nm.substring(nm.lastIndexOf(‘.’) + 1);jPanel.add(new JLabel(nm, JLabel.CENTER), BorderLayout.CENTER);jPanel.setBorder(b);return jPanel;}public Borders() {setLayout(new GridLayout(2, 4));add(showBorder(new TitledBorder(“Title”)));add(showBorder(new EtchedBorder()));add(showBorder(new LineBorder(Color.blue)));add(showBorder(new MatteBorder(5, 5, 30, 30, Color.green)));add(showBord

Similar Posts

发表评论

邮箱地址不会被公开。 必填项已用*标注