窗口、菜单和对话框

第九章窗口、菜单和对话框,本章的任务：介绍图形用户界面的高级组件。这些组件包括窗口、菜单和对话框等，它们可以构造出标准GUI应用程序。最后，简要介绍JavaSwing的使用方法。,本章主要内容,1.窗口2.菜单3.对话框4.Swing简介,9.1窗口,Java的窗口由Frame类生成，遗憾的是它不具有关闭功能，必须要在程序中实现窗口事件监听接口并编写关闭窗口的代码才行。本节介绍创建可关闭窗口的几种方法以及窗口的使用。,9.1.1创建可关闭窗口,例9.1方式1：创建一个可关闭的空白窗口，如图所示。,importjava.awt.*;importjava.awt.event.*;classW1extendsFrameimplementsWindowListenerW1()super(Window1);setSize(350,200);setVisible(true);addWindowListener(this);,publicvoidwindowClosing(WindowEvente)System.exit(0);publicvoidwindowOpened(WindowEvente)publicvoidwindowClosed(WindowEvente)publicvoidwindowIconified(WindowEvente)publicvoidwindowDeiconified(WindowEvente)publicvoidwindowActivated(WindowEvente)publicvoidwindowDeactivated(WindowEvente)publicstaticvoidmain(Stringargs)newW1();,9.1.2窗口事件适配器,例9.2方式2：创建一个可关闭的空白窗口。importjava.awt.*;importjava.awt.event.*;publicclassW2extendsFrameW2()super(Window2);setSize(350,200);setVisible(true);addWindowListener(newWin();,publicstaticvoidmain(Stringargs)newW2();classWinextendsWindowAdapterpublicvoidwindowClosing(WindowEvente)System.exit(0);,窗口事件适配器是为方便程序员而专门设计的类。定义：,publicabstractclassWindowAdapterextendsObjectimplementsWindowListenerpublicWindowAdapter()/构造方法publicvoidwindowOpened(WindowEvente)/窗口被打开后调用publicvoidwindowClosing(WindowEvente)/窗口被关闭时调用publicvoidwindowClosed(WindowEvente)/窗口被关闭后调用publicvoidwindowIconified(WindowEvente)/窗口被缩小为图标时调用publicvoidwindowDeiconified(WindowEvente)/窗口被复原时调用publicvoidwindowActivated(WindowEvente)/窗口激活时调用publicvoidwindowDeactivated(WindowEvente)/窗口失活时调用,9.1.3匿名类,例9.3方式3：创建一个可关闭的空白窗口。importjava.awt.*;importjava.awt.event.*;publicclassW3publicstaticvoidmain(Stringargs)Framef=newFrame(Window3);f.setSize(350,200);f.setVisible(true);f.addWindowListener(newWindowAdapter()publicvoidwindowClosing(WindowEvente)System.exit(0););,9.1.4在窗口中加入组件,例9.4在窗口中添加按钮，点击“显示”按钮可以显示文字，点击“退出”按钮可关闭窗口，同时窗口右上角的关闭按钮也起作用。如图所示。,importjava.awt.*;importjava.awt.event.*;publicclassW4extendsFrameimplementsActionListenerButtonbtn1,btn2;TextFieldf;W4()super(Window4);addWindowListener(newWindowAdapter()publicvoidwindowClosing(WindowEvente)System.exit(0););,setSize(350,200);btn1=newButton(显示);btn2=newButton(退出);f=newTextField(20);setLayout(newFlowLayout();add(f);add(btn1);add(btn2);btn1.addActionListener(this);btn2.addActionListener(this);show();,publicstaticvoidmain(Stringargs)newW4();publicvoidactionPerformed(ActionEvente)f.setText(你按下了“+e.getActionCommand()+”按钮);if(e.getSource()=btn2)for(inti=0;i100000000;i+);System.exit(0);,9.1.5多重窗口,例9.5设计一个多重窗口的程序，如图所示。,importjava.awt.*;importjava.awt.event.*;publicclassW5extendsFrameimplementsActionListenerButtonbtn;W5()super(Window5);addWindowListener(newWindowAdapter()publicvoidwindowClosing(WindowEvente)System.exit(0););,setSize(350,200);btn=newButton(打开新窗口);setLayout(newFlowLayout();add(btn);btn.addActionListener(this);setLocation(200,100);show();,publicstaticvoidmain(Stringargs)newW5();publicvoidactionPerformed(ActionEvente)newW5();setLocation(getX()+20,getY()+20);toFront();,9.2菜单,菜单是图形用户界面的重要组成部分。由菜单条（MenuBar）、菜单（Menu）、菜单项（MenuItem）和复选菜单项（CheckboxMenuItem）等对象组成。,9.2.1为窗口加入菜单,例9.6在窗口中添加菜单，如图所示。,importjava.awt.*;importjava.awt.event.*;publicclassW6extendsFrameimplementsActionListenerPanelp=newPanel();Buttonbtn=newButton(退出);MenuBarmb=newMenuBar();/以下生成菜单组件对象Menum1=newMenu(文件);MenuItemopen=newMenuItem(打开);MenuItemclose=newMenuItem(关闭);MenuItemexit=newMenuItem(退出);,Menum2=newMenu(编辑);MenuItemcopy=newMenuItem(复制);MenuItemcut=newMenuItem(剪切);MenuItempaste=newMenuItem(粘贴);Menum3=newMenu(帮助);MenuItemcontent=newMenuItem(目录);MenuItemindex=newMenuItem(索引);MenuItemabout=newMenuItem(关于);,W6()super(Window6);setSize(350,200);add(South,p);p.add(btn);btn.addActionListener(this);m1.add(open);/将菜单项加入到菜单中m1.add(close);m1.addSeparator();/将分隔条加入到菜单中m1.add(exit);exit.addActionListener(this);/注册菜单项的事件监听器mb.add(m1);/将菜单加入到菜单条中,m2.add(copy);m2.add(cut);m2.add(paste);mb.add(m2);m3.add(content);m3.add(index);m3.addSeparator();m3.add(about);mb.add(m3);,setMenuBar(mb);/显示菜单条show();publicstaticvoidmain(Stringargs)newW6();publicvoidactionPerformed(ActionEvente)if(e.getActionCommand()=退出)System.exit(0);,9.2.2菜单综合应用,例9.7菜单综合应用，如图所示。,importjava.awt.*;importjava.awt.event.*;publicclassW7extendsFrameimplementsActionListener,ItemListenerTextFieldmsg=newTextField();MenuBarmb=newMenuBar();Menum1=newMenu(菜单);Menum2=newMenu(二级菜单);MenuItemitem=newMenuItem(普通菜单项,newMenuShortcut(p);CheckboxMenuItemcheckbox=newCheckboxMenuItem(复选菜单项);MenuItemexit=newMenuItem(退出);,W7()setTitle(菜单综合应用);setSize(350,200);add(msg);mb.add(m1);m1.add(m2);/将二级菜单m2加入到m1中checkbox.setState(true);/设定复选菜单项为选中m1.add(item);m1.add(checkbox);m1.addSeparator();m1.add(exit);m2.add(菜单项);/为二级菜单m2加入菜单项m2.add(菜单项);,item.addActionListener(this);/注册事件监听器checkbox.addItemListener(this);exit.addActionListener(this);setMenuBar(mb);/显示菜单show();/显示窗口publicvoidactionPerformed(ActionEvente)if(e.getSource()=exit)System.exit(0);elsemsg.setText(e.getActionCommand()+被打开);,publicvoiditemStateChanged(ItemEvente)if(e.getSource()=checkbox)if(checkbox.getState()msg.setText(checkbox.getLabel()+被选中);elsemsg.setText(checkbox.getLabel()+被取消);publicstaticvoidmain(Stringarg)newW7();,9.2.3弹出式菜单,弹出式菜单是一种非常方便的菜单工具，它平常依附在某个容器或组件上并不显现出来，当用户点击鼠标右键时它就会弹出来。,例9.8弹出式菜单应用，如图所示。,importjava.awt.*;importjava.awt.event.*;publicclassW8extendsFrameimplementsActionListener,MouseListenerTextAreamsg=newTextArea();PopupMenupm=newPopupMenu();MenuItemitem1=newMenuItem(复制);MenuItemitem2=newMenuItem(剪切);MenuItemitem3=newMenuItem(粘贴);,W8()setTitle(弹出式菜单);setSize(350,200);addWindowListener(newWindowAdapter()/注册窗口的事件监听器publicvoidwindowClosing(WindowEvente)System.exit(0););add(msg);msg.add(pm);/将弹出式菜单加入到文本区中pm.add(item1);pm.add(item2);pm.add(item3);,item1.addActionListener(this);item2.addActionListener(this);item3.addActionListener(this);msg.addMouseListener(this);/注册文本区的鼠标事件监听器show();publicvoidactionPerformed(ActionEvente)msg.append(你选择了+e.getActionCommand()+n);,publicvoidmouseReleased(MouseEvente)if(e.isPopupTrigger()/判断是否按下鼠标右键pm.show(this,e.getX(),e.getY();/显示弹出式菜单publicvoidmouseClicked(MouseEvente)publicvoidmouseEntered(MouseEvente)publicvoidmouseExited(MouseEvente)publicvoidmousePressed(MouseEvente)publicstaticvoidmain(Stringarg)newW8();,9.3对话框,对话框是GUI中很常见的窗口对象，有着广泛的应用。对话框和普通窗口最大的不同就是对话框是依附在某个窗口上，一旦它所依附的窗口关闭了，对话框也要随着关闭。,9.3.1自定义对话框,Dialog有7个构造方法：Dialog(Dialogowner)Dialog(Dialogowner,Stringtitle)Dialog(Dialogowner,Stringtitle,booleanmodal)Dialog(Frameowner)Dialog(Frameowner,booleanmodal)Dialog(Frameowner,Stringtitle)Dialog(Frameowner,Stringtitle,booleanmodal),9.3.2创建自定义对话框实例,例9.9建立一个自定义对话框，如下两图。,importjava.awt.*;importjava.awt.event.*;publicclassW9extendsFrameimplementsActionListenerintrow=6,col=40;Panelp1=newPanel(),p2=newPanel();TextAreata=newTextArea(文本区行数:+row+列数:+col,row,col);Buttonexit=newButton(退出),dialog=newButton(对话框);,W9()setTitle(对话框的父窗口);setSize(350,200);add(Center,p1);add(South,p2);p1.add(ta);p2.add(exit);p2.add(dialog);exit.addActionListener(this);dialog.addActionListener(this);setVisible(true);,publicstaticvoidmain(Stringargs)newW9();publicvoidactionPerformed(ActionEvente)if(e.getSource()=exit)System.exit(0);elseMyDialogdlg=newMyDialog(this,true);dlg.show();,classMyDialogextendsDialogimplementsActionListenerLabellabel1=newLabel(请输入行数);Labellabel2=newLabel(请输入列数);TextFieldrows=newTextField(50);TextFieldcolumns=newTextField(50);ButtonOK=newButton(确定);ButtonCancel=newButton(取消);,MyDialog(W9parent,booleanmodal)super(parent,modal);setTitle(自定义对话框);setSize(260,140);setResizable(false);setLayout(null);add(label1);add(label2);label1.setBounds(50,30,65,20);label2.setBounds(50,60,65,20);,add(rows);add(columns);rows.setText(Integer.toString(ta.getRows();columns.setText(Integer.toString(ta.getColumns();rows.setBounds(120,30,90,20);columns.setBounds(120,60,90,20);add(OK);add(Cancel);OK.setBounds(60,100,60,25);Cancel.setBounds(140,100,60,25);OK.addActionListener(this);Cancel.addActionListener(this);,publicvoidactionPerformed(ActionEvente)if(e.getSource()=OK)introw=Integer.parseInt(rows.getText();intcol=Integer.parseInt(columns.getText();ta.setRows(row);ta.setColumns(col);ta.setText(文本区行数:+row+列数:+col);dispose();,9.4Swing简介,Swing的功能：Swing按钮类和标签类除了显示文本标题外还可以显示图像标题。可以为Swing容器加上边框。Swing组件能自动适应操作系统的外观，而AWT组件总是保持相同外观。Swing组件不一定非得是矩形的，可以把按钮设计成圆形。可以调用Swing组件的方法改变其外观和行为。,9.4.1Swing按钮与标签,例9.10图像按钮与图像标签应用，如图所示。,importjavax.swing.*;importjava.awt.*;importjava.awt.Color;publicclassW11extendsJAppletContainerpane;JPanelpanel1,panel2;JButtonbutton1,button2,button3;JLabellabel;,publicvoidinit()pane=getContentPane();panel1=newJPanel(newFlowLayout();panel2=newJPanel(newFlowLayout();ImageIconicon=newImageIcon(PreviousArrow.gif,);button1=newJButton(icon);button2=newJButton(newImageIcon(image/go.GIF);button3=newJButton(newImageIcon(NextArrow.gif);label=newJLabel(图像标签,newImageIcon(Candl02.gif),SwingConstants.CENTER);,pane.setBackground(newColor(255,255,204);panel1.setBackground(newColor(255,255,204);panel2.setBackground(newColor(255,255,204);button1.setToolTipText(向上翻页按钮);button2.setToolTipText(跳转按钮);button3.setToolTipText(向下翻页按钮);,pane.add(panel1,BorderLayout.NORTH);pane.add(panel2,BorderLayout.SOUTH);panel1.add(button1);panel1.add(button2);panel1.add(button3);panel2.add(label);,9.4.2Swing工具栏,例9.11工具栏与文本区应用，如图所示。,importjavax.swing.*;importjava.awt.*;importjava.awt.event.*;publicclassW12extendsJFrameimplementsActionListenerJButtonbutton1,button2,button3;JToolBartoolBar;JTextAreatextArea;JScrollPanescrollPane;JPanelpanel;publicW12()super(工具栏按钮);addWindowListener(newWindowAdapter()publicvoidwindowClosing(WindowEvente)System.exit(0););,button1=newJButton(newImageIcon(left.gif);button2=newJButton(newImageI