Microsoft PowerPoint - course8.ppt

Size: px

Start display at page:

Download "Microsoft PowerPoint - course8.ppt"

炉温屈
7 years ago
Views:

1 回顧 Java 程式設計基礎班 (8) Java Data Structure 劉根豪台大電機所網路資料庫研究室 Java AWT package Java Swing package Component: 一些 GUI 元件, 如 :Button Label 等 Container: 用來放置 GUI 元件的地方 Container 可分為兩種供使用者使用 : Frame(Window): 一個開出來的視窗 Panel: 放在 Frame 裡的畫布, 一個 Frame 裡可以有多個 Panel 修改自 awt 提供更強大的繪圖元件功能, 以及更穩定的函式庫 Swing Container 可分為兩種供使用者使用 : JFrame(Window): 一個開出來的視窗 JPanel: 放在 JFrame 裡的畫布, 一個 JFrame 裡可以有多個 JPanel 3 4 第一個小程式 JFrame 的使用 JPanel 的使用見 exercise8_1 見 exercise8_

2 Layout Managers 把元件放在我們希望放置的地方! FlowLayout:Panel 與 Applet 預設使用的 layout 方式 BorderLayout:Windows Dialogs 與 Frames 的預設使用的 layout 方式 GridLayout CardLayout GridBagLayout Null 不設定任何 Layout FlowLayout Manager ㄧ行接著一行就是說元件一個接著一個的放在上面, 放滿了就會換行, 有點像打字超過一行字數會自動換行般 7 8 public class MyFlow private JFrame f; private JButton btn1, btn2, btn3; public static void main( String args[] ) MyFlow aflow = new MyFlow(); aflow.go(); public void go() f = new JFrame( "FlowLayout Manager" ); // 使用 FlowLayout Manager, 對齊方式靠左,default 對齊方式為置中 f.setlayout( new FlowLayout( FlowLayout.LEFT ) ); btn1 = new JButton( "Button1" ); // 產生三個按鈕 btn2 = new JButton( "Button2" ); btn3 = new JButton( "Button3" ); f.add( btn1 ); // 把 Button 加到 Frame 上 f.add( btn2 ); f.add( btn3 ); f.setsize( 100, 100 ); f.setvisible( true ); 9 10 BorderLayout Manager BorderLayout 包含五種不同區域 : North,South,Ease,West,Center 元件的相對位置不會隨 window size 的改變而改變, 但元件的 size 將可能改變看個例子 : public class MyBorder private JFrame f; private JButton btnnorth, btnsouth, btneast, btnwest, btncenter; public static void main( String args[] ) MyBorder aborder = new MyBorder(); aborder.go(); [ next ]

3 public void go() f = new JFrame( "BorderLayout Manager" ); //Frame 預設使用 BorderLayout f.setlayout( new BorderLayout() ); // 採用 BorderLayout 的方式來排列元件 btnnorth = new JButton( "ButtonNorth" ); btnsouth = new JButton( "ButtonSouth" ); btneast = new JButton( "ButtonEast" ); btnwest = new JButton( "ButtonWest" ); btncenter = new JButton( "ButtonCenter"); f.add( btnnorth, BorderLayout.NORTH ); // 將五個按鈕分別加在五個位置上 f.add( btnsouth, BorderLayout.SOUTH ); f.add( btneast, BorderLayout.EAST ); f.add( btnwest, BorderLayout.WEST ); f.add( btncenter, BorderLayout.CENTER ); f.setsize( 300, 100 ); f.setvisible( true ); GridLayout Manager 讓你在畫布上打格子, 元件就可以方便的放在特定的位置裡, 每個方格的大小是一樣的加入順序 : 由左至右 / 由上至下看個例子 : public class MyGrid private JFrame f; private JButton btn11, btn12, btn13; private JButton btn21, btn22, btn23; public static void main( String args[] ) MyGrid agrid = new MyGrid(); agrid.go(); public void go() f = new JFrame( "GridLayout Manager" ); // 使用 GridLayout 方式排列元件 // 將 Frame 分成 row=3, col=2 的區塊 f.setlayout( new GridLayout( 3, 2 ) ); 15 [ next ] 16 btn11 = new JButton( "Button(1,1)" ); btn12 = new JButton( "Button(1,2)" ); btn13 = new JButton( "Button(1,3)" ); btn21 = new JButton( "Button(2,1)" ); btn22 = new JButton( "Button(2,2)" ); btn23 = new JButton( "Button(2,3)" ); // 將入六個按鈕, 加入順序 : 由左至右 / 由上至下 f.add( btn11 ); f.add( btn12 ); f.add( btn13 ); f.add( btn21 ); f.add( btn22 ); f.add( btn23 ); f.setsize( 300, 200 ); f.setvisible( true );

4 AWT/Swing Component Library Label public class mylabel extends JFrame public static void main( String args[] ) mylabel labelexam = new mylabel( "Label Example" ); JLabel label1 = new JLabel( "Sample" ); p.add( label1 ); labelexam.add( p ); labelexam.setsize( 100, 100 ); labelexam.setvisible( true ); public mylabel( String title ) super (title); Button public class mybutton extends JFrame public static void main( String args[] ) mybutton btnexam = new mybutton( "Button Example" ); JButton btn1 = new JButton( "Sample" ); p.add( btn1 ); btnexam.add( p ); btnexam.setsize( 100, 100 ); btnexam.setvisible( true ); public mybutton( String title ) super (title);

5 Checkbox public class mycheckbox extends Frame public static void main( String args[] ) mycheckbox chkboxexam = new mycheckbox( "CheckBox Example" ); JCheckbox chkbox1 = new JCheckbox( "One", false ); JCheckbox chkbox2 = new JCheckbox( "Two", false ); JCheckbox chkbox3 = new JCheckbox( "Three", true ); p.add( chkbox1 ); p.add( chkbox2 ); p.add( chkbox3 ); chkboxexam.add( p ); chkboxexam.setsize( 300, 100 ); chkboxexam.setvisible( true ); public mycheckbox( String title ) super (title); CheckboxGroup - Radio Button true public class mycheckboxgroup extends JFrame public static void main( String args[] ) mycheckboxgroup radiobtnexam = new mycheckboxgroup("checkbox Example"); JRadioButton radiobtn1 = new JRadioButton( "One"); JRadioButton radiobtn2 = new JRadioButton( "Two"); JRadioButton radiobtn3 = new JRadioButton( "Three"); ButtonGroup bg = new ButtonGroup(); bg.add(radiobtn1); bg.add(radiobtn2); bg.add(radiobtn3); p.add( radiobtn1 ); p.add( radiobtn2 ); p.add( radiobtn3 ); radiobtnexam.add( p ); radiobtnexam.setsize( 3100, 100 ); radiobtnexam.setvisible( true ); public mycheckboxgroup( String title ) super (title);

6 Choice:"select one from this list" public class mychoice extends JFrame public static void main( String args[] ) mychoice choiceexam = new mychoice( "Choice Example" ); String[] items = First, Second, Three ; JComboBox c = new JComboBox(items); p.add( c ); choiceexam.add( p ); choiceexam.setsize( 100, 100 ); choiceexam.setvisible( true ); public mychoice( String title ) super (title); List public class mylist extends JFrame public static void main( String args[] ) mylist listexam = new mylist( "List Example" ); String[] items = First, Second, Third ; JList c = new JList( items); p.add( c ); listexam.add( p ); listexam.setsize( 100, 100 ); listexam.setvisible( true ); public mylist( String title ) super (title);

7 TextField public class mytextfield extends JFrame public static void main( String args[] ) mytextfield txtfieldexam = new mytextfield( "TextField Example" ); JTextField txtfield1 = new JTextField( "Sample", 20 ); p.add( txtfield1 ); txtfieldexam.add( p ); txtfieldexam.setsize( 100, 100 ); txtfieldexam.setvisible( true ); public mytextfield( String title ) super (title); TextArea public class mytextarea extends JFrame public static void main( String args[] ) mytextarea txtareaexam = new mytextarea( "TextArea Example" ); JTextArea txtarea1 = new JTextArea( "Sample", 4, 20 ); p.add( txtarea1 ); txtareaexam.add( p ); txtareaexam.setsize( 100, 100 ); txtareaexam.setvisible( true ); public mytextarea( String title ) super (title);

8 Dialog public class mydialog extends JFrame public static void main( String args[] ) mydialog dialogexam = new mydialog( "Dialog Example" ); JDialog dialog1 = new JDialog( dialogexam, "Sample", false ); dialog1.add( new Label( "Hello, Dialog..." ), BorderLayout.CENTER ); dialog1.pack(); dialog1.setvisible( true ); dialogexam.setsize( 100, 100 ); dialogexam.setvisible( true ); public mydialog( String title ) super (title); FileDialog public class myfiledialog extends JFrame public static void main( String args[] ) myfiledialog fdialogexam = new myfiledialog( "FileDialog Example" ); String fname= ; JFileChooser chooser = new JFileChooser(); int returnval = chooser.showopendialog(parent); if(returnval == JFileChooser.APPROVE_OPTION) fname = chooser.getselectedfile().getname(); Label l1 = new Label( fname ); p.add( l1 ); fdialogexam.add( p ); fdialogexam.setsize( 100, 100 ); fdialogexam.setvisible( true ); public myfiledialog( String title ) super (title);

9 MenuBar Menu MenuItem public class mymenu extends JFrame public static void main( String args[] ) mymenu menuexam = new mymenu( "Menu Bar/Menu/Menu Item" ); JMenuBar mb = new JMenuBar(); JMenu m1 = new JMenu( "File" ); JMenu m2 = new JMenu( "Edit" ); mb.add( m1 ); mb.add( m2 ); JMenuItem m1_open = new JMenuItem( "Open" ); JMenuItem m1_save = new JMenuItem( "Save" ); JMenuItem m1_exit = new JMenuItem( Exit" ); m1.add( m1_open ); m1.add( m1_save ); m1.addseparator(); m1.add( m1_exit ); menuexam.setjmenubar( mb ); menuexam.setsize( 100, 100 ); menuexam.setvisible( true ); 49 public mymenu( String title ) super (title); 50 import java.awt.event.*; public class mypopupmenu extends JFrame implements ActionListener private JButton b; private JPopupMenu pop1; public static void main( String args[] ) mypopupmenu popexam = new mypopupmenu( "PopupMenu Example" ); popexam.setsize( 100, 100 ); popexam.setvisible( true ); [ next page ] 事件處理函式 GUI Controls 和 Listeners GUI 事件驅動模型 GUI 事件發生時再通知我包括移動滑鼠按鍵或輸入資料等等 java.awt.awtevent 三要素 Source Buttons 等 GUI 控制 Listener 想要知道控制何時被操作的物件通知訊息訊息從 Source 送到 Listener 來當作事件已經發生的通知註冊 Callback 函式

10 Listeners 和 Interface java.awt.awtevent 物件可能對多個事件有興趣實現多重 listener 介面一旦物件實現 listener 介面就可以被加到 source source.addlistener(listener l) 介面是實現 Listener 模型的關鍵 Object EventObject AWTEvent ActionEvent AdjustmentEvent ItemEvent TextEvent ComponentEvent KeyEvent ContainerEvent FocusEvent PaintEvent WindowEvent InputEvent MouseEvent MouseWheelEvent Source-Listener 的互動 Listener Interface addlistener Listener ActionListener Interface 聆聽 JButton 的物件必須實現 ActionListener Listener Source addlistener Notification of event public interface ActionListener extends EventListener /** * Invoked when an action occurs. */ public void actionperformed(actionevent e); Notification Prototype source.addxxx(listener) 介面 ActionListener 定義 message prototype JButton 送出的訊息 ActionEvent 參數包括額外資訊來源物件 (e.getsource()) 發生時間鍵盤組合鍵 Listener 向 Source 登記來建立關係 Example: button.addactionlistener(listener) Listener 必須實現 ActionListener 介面必須回應 button 將會送出的訊息 public void actionperformed(actionevent e);

11 Event Notification 當動作發生時 Button is clicked Source 發送通知給每一個 Listener JButton 發送 actionperformed() 訊息給每一個 listener Using a Button and a Listener #1 Component implements ActionListener The component could implement the ActionListener interface directly Register this as the listener object class MyComponent extends JComponent implements ActionListener... // in the JComponent ctor button.addactionlistener(this); Using a Button and a Listener #2 Anonymous Inner class Create an inner class Create a MyListener inner class which implements ActionListener Create a new MyListener object Add it via button.addxxx(listener) // in the JComponent ctor ActionListener listener = new MyActionListener(); button.addactionlistener(listener); Most common method! Create an Anonymous Inner Class that implements the interface Can be created on the fly inside the method! button = new JButton("Beep"); panel.add(button); button.addactionlistener( new ActionListener() public void actionperformed(actionevent e) Toolkit.getDefaultToolkit().beep(); ); Button Listener Example ButtonListener Example Code // ListenerFrame.java import javax.swing.event.*; import java.awt.event.*; /* Demonstrates bringing up a frame with a couple of buttons in it. Demonstrates using anonymous inner class listener. */ public class ListenerFrame extends JFrame private JLabel label;

12 Button Listener Example Button Listener Example public ListenerFrame() super("listenerframe"); JComponent content = (JComponent) getcontentpane(); content.setlayout(new FlowLayout()); JButton button = new JButton("Beep!"); content.add(button); // 2. Add the listener to the button button.addactionlistener(listener); // ---- // Creating a listener in 1 step... // ---- // Creating an action listener in 2 steps... // 1. Create an inner class subclass of ActionListener ActionListener listener = new ActionListener() public void actionperformed(actionevent e) Toolkit.getDefaultToolkit().beep(); ; // Create a little panel to hold a button // and a label JPanel panel = new JPanel(); content.add(panel); JButton button2 = new JButton("Yay!"); label = new JLabel("Woo Hoo"); panel.add(button2); panel.add(label); Button Listener Example // This listener adds a "!" to the label. button2.addactionlistener( new ActionListener() public void actionperformed(actionevent e) String text = label.gettext(); label.settext(text + "!"); // note: we have access to "label" of outer class // we do not have access to local vars like 'panel', // unless they are declared final. ); Misc. Listeners JCheckBox Uses ActionListener, like JButton Responds to boolean isselected() to see if it is currently checked pack(); setvisible(true); PopupMenu public mypopupmenu( String title ) super (title); pop1 = new JPopupMenu( "Popup Sample" ); JMenuItem s = new JMenuItem( "Save" ); JMenuItem l = new JMenuItem( "Load" ); b = new JButton( "Press me" ); add( b, "Center" ); b.addactionlistener( this ); pop1.add( s ); pop1.add( l ); add( pop1 ); public void actionperformed( ActionEvent ev ) pop1.show( b, 10, 10 );

13 Color Controlling 設定 component 的顏色 setforeground(): 設定前景顏色 setbackgroud(): 設定背景顏色自訂顏色 : RGB 三個參數 Red, Green, Blue, 範圍 :0 ~ 255 int r=255, g=255, b=0; Color c = new Color( r, g, b ); public class mycolor extends Frame public static void main( String args[] ) mycolor btnexam = new mycolor( "Color Example" ); Color newcolor = new Color( 200, 100, 0 ); Button btn1 = new Button( "Color ForeGround Green" ); Button btn2 = new Button( "Color BackGround Blue" ); Button btn3 = new Button( "Color BackGround User Define(200, 100, 0)" ); btn1.setforeground( Color.yellow ); btn2.setbackground( Color.blue ); btn3.setbackground( newcolor ); p.add( btn1 ); p.add( btn2 ); p.add( btn3 ); btnexam.add( p ); btnexam.setsize( 100, 100 ); btnexam.setvisible( true ); public mycolor( String title ) super (title); public class myfont extends Frame public static void main( String args[] ) myfont btnexam = new myfont( "Font Example" ); Font f1 = new Font( "Dialog", Font.BOLD, 25 ); Font f2 = new Font( "Courier", Font.ITALIC, 35 ); Font f3 = new Font( "TimesRoman", Font.PLAIN, 45 ); Button btn1 = new Button( "Font Dialog/BOLD/25 " ); Button btn2 = new Button( "Font Courier/ITALIC/35" ); Button btn3 = new Button( "Font TimesRoman/PLAIN/45" ); btn1.setfont( f1 ); btn2.setfont( f2 ); btn3.setfont( f3 ); p.add( btn1 ); p.add( btn2 ); p.add( btn3 ); btnexam.add( p ); btnexam.setsize( 100, 100 ); btnexam.setvisible( true ); public myfont( String title ) super (title); Font Controlling 設定 component 上的字體, 包括 (Font Name/Style/Size)

14 79 14

Microsoft PowerPoint ppt

Microsoft PowerPoint ppt Java 程式設計基礎班 (8) 莊坤達台大電信所網路資料庫研究室 Email: doug@arbor.ee.ntu.edu.tw Class 8 1 回顧 Java Data Structure Class 8 2 Java AWT package Component: 一些 GUI 元件, 如 : Button Label 等 Container: 用來放置 GUI 元件的地方 Container