菜鸟学Java之第八章（图形界面设计）

第八章.图形界面设计

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主要内容：8.1 Swing基础  8.2 Swing常用组件  8.3 事件  8.4 布局管理器

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案例－简易文本编辑器的制作

 

简易文本编辑器主要功能如图8.1所示，利用简易文本编辑器，可以进行文本的输入、复制、剪切、粘贴及选择操作，还可以根据需要设置文字的大小及字形。

如实现本例功能需使用到本章介绍的多个知识点：

1.Swing常用组件的定义和构造；

2.布局管理器：本例中主要使用了边界布局BorderLayout，流布局FlowLayout及网格布局GridLauout；

3.JAVA事件：事件处理机制，组件的常用事件，事件处理机制的实际应用。

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应用效果图如下：

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代码如下：

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

import java.io.*;
import javax.swing.filechooser.*;

import java.awt.datatransfer.*;
public class TxtEditor extends JFrame 
{
	JFrame frmAbout;
	JTextArea taArea;
	String name=null;
	String board=null;
	private Clipboard cb;
	JScrollPane scroll;
	JPanel PanelNorth,PanelSouth,PanelWest,PanelEast,PanelCenter,PanelLeftFontSize,PanelLeftFontType;
	JButton btnNew,btnOpen,btnSave,btnSaveAnother,btnCopy,btnPaste,btnCut,btnDelete,btnSelectAll,btnHelp;
	JRadioButton jrbFontSize10,jrbFontSize20,jrbFontSize30;
	JCheckBox jcbBold,jcbItalic;
	ButtonGroup jbgFontSize;
	JLabel lblTitle;
	public TxtEditor() throws Exception{
		super("简易文本编辑器");Toolkit kit=Toolkit.getDefaultToolkit();
		PanelNorth=new JPanel();PanelSouth=new JPanel();PanelWest=new JPanel();PanelEast=new JPanel();
		PanelCenter=new JPanel();PanelLeftFontSize=new JPanel();PanelLeftFontType=new JPanel();
		btnNew=new JButton("新建");btnOpen=new JButton("打开");btnSave=new JButton("保存");
		btnSaveAnother=new JButton("另存为");btnCopy=new JButton("复制");btnPaste=new JButton("粘贴");
		btnCut=new JButton("剪切");btnDelete=new JButton("删除");btnSelectAll=new JButton("全选");
		btnHelp=new JButton("帮助");
		jrbFontSize10=new JRadioButton("10",true);jrbFontSize20=new JRadioButton("20");jrbFontSize30=new JRadioButton("30");
		jcbBold=new JCheckBox("粗体",false);jcbItalic=new JCheckBox("斜体",false);
		taArea=new JTextArea(10,50);taArea.setFont(new Font("黑体",Font.BOLD,15));
		scroll=new JScrollPane(taArea);
        scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
		jbgFontSize=new ButtonGroup();lblTitle=new JLabel("简易文本编辑器");
		jbgFontSize.add(jrbFontSize10);jbgFontSize.add(jrbFontSize20);jbgFontSize.add(jrbFontSize30);
		PanelNorth.add(lblTitle);
		PanelSouth.add(btnNew);PanelSouth.add(btnOpen);PanelSouth.add(btnSave);PanelSouth.add(btnSaveAnother);
		PanelSouth.add(btnCopy);PanelSouth.add(btnPaste);PanelSouth.add(btnCut);PanelSouth.add(btnDelete);
		PanelSouth.add(btnSelectAll);
		PanelSouth.add(btnHelp);
		PanelWest.setLayout(new GridLayout(6,1));
		PanelLeftFontSize.add(jrbFontSize10);PanelLeftFontSize.add(jrbFontSize20);
		PanelLeftFontSize.add(jrbFontSize30);
		PanelLeftFontType.add(jcbBold);PanelLeftFontType.add(jcbItalic);
		PanelWest.add(PanelLeftFontSize);PanelWest.add(PanelLeftFontType);
		PanelCenter.add(scroll);
		this.add(PanelNorth,BorderLayout.NORTH);this.add(PanelSouth,BorderLayout.SOUTH);this.add(PanelWest,BorderLayout.WEST);
		this.add(PanelEast,BorderLayout.EAST);this.add(PanelCenter,BorderLayout.CENTER);
		btnSave.addActionListener(new MyListenerSave());
		btnOpen.addActionListener(new MyListenerOpen());
		btnNew.addActionListener(new MyListenerNew());
		btnSaveAnother.addActionListener(new MyListenerAnother());
		btnCopy.addActionListener(new MyListenerCopy());
        btnPaste.addActionListener(new MyListenerPaste());
        btnCut.addActionListener(new MyListenerCut());
        btnDelete.addActionListener(new MyListenerDelete());
        btnSelectAll.addActionListener(new MyListenerSelectAll());
        jcbBold.addItemListener(new MyListenerjcbBold());
		jcbItalic.addItemListener(new MyListenerjcbItalic());
		jrbFontSize10.addActionListener(new MyListenerjrbFontSize10());
		jrbFontSize20.addActionListener(new MyListenerjrbFontSize20());
		jrbFontSize30.addActionListener(new MyListenerjrbFontSize30());
		btnHelp.addActionListener(new MyListenerHelp());
		this.setSize(800,320);
		this.setLocation(300,200);
		this.setVisible(true);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);				
	    cb=Toolkit.getDefaultToolkit().getSystemClipboard();			
	}
	public class MyListenerSave implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			try{
				
				saveText();
				}catch(Exception ex)
				{
				}
		}	
	}
	public class MyListenerOpen implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			try{
				openText();
				}catch(Exception ex)
				{
				}
		}	
	}
	public class MyListenerNew implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			try{
				taArea.setText("");
			name=null;
			}catch(Exception ex)
			{}
		}	
	}
	public class MyListenerAnother implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			anotherSaveText();
		}	
	}
	public class MyListenerCopy implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			board=taArea.getSelectedText();
			cb.setContents(new StringSelection(board),null);
		}	
	}
	public class MyListenerPaste implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			try{
				taArea.setForeground(Color.BLACK);
				Transferable content=cb.getContents(null);
				String st=(String)content.getTransferData(DataFlavor.stringFlavor);
				taArea.replaceRange(st,taArea.getSelectionStart(),taArea.getSelectionEnd());
				}catch(Exception ex)
				{}
		}	
	}	
	public class MyListenerCut implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			board=taArea.getSelectedText();
			cb.setContents(new StringSelection(board),null);
			taArea.replaceRange("",taArea.getSelectionStart(),taArea.getSelectionEnd());
		}	
	}	
	public class MyListenerDelete implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			int result=JOptionPane.showConfirmDialog(null,"您确定要删除选定文本?","确认对话框",JOptionPane.YES_NO_OPTION);
			if(result==JOptionPane.OK_OPTION)
			{
			taArea.replaceRange("",taArea.getSelectionStart(),taArea.getSelectionEnd());				
			}
		}	
	}	
	public class MyListenerSelectAll implements ActionListener{
		public void actionPerformed(ActionEvent e)
		{
			taArea.setSelectionStart(0);
			taArea.setSelectionEnd(taArea.getText().length());
			taArea.setForeground(Color.BLUE);
		}	
	}	
	public class MyListenerjrbFontSize10 implements ActionListener{
		public void actionPerformed(ActionEvent e){
			Font oldFont=taArea.getFont();
			Font newFont=new Font(oldFont.getFontName(),oldFont.getStyle(),10);
			taArea.setFont(newFont);
		}
	}
	public class MyListenerjrbFontSize20 implements ActionListener{
		public void actionPerformed(ActionEvent e){
			Font oldFont=taArea.getFont();
			Font newFont=new Font(oldFont.getFontName(),oldFont.getStyle(),20);
			taArea.setFont(newFont);
		}
	}
	public class MyListenerjrbFontSize30 implements ActionListener{
		public void actionPerformed(ActionEvent e){
			Font oldFont=taArea.getFont();
			Font newFont=new Font(oldFont.getFontName(),oldFont.getStyle(),30);
			taArea.setFont(newFont);
		}
	}
	public class MyListenerjcbBold implements ItemListener{
		public void itemStateChanged(ItemEvent e)
		{
			Font oldFont=taArea.getFont();
			int style=oldFont.getStyle();
			if(jcbBold.isSelected()){
				style+=Font.BOLD;				
				}
				else
				{
				style-=Font.BOLD;	
				}
			Font newFont=new Font(oldFont.getFontName(),style,oldFont.getSize());
			taArea.setFont(newFont);
		}	
	}
	public class MyListenerjcbItalic implements ItemListener{
		public void itemStateChanged(ItemEvent e){
			Font oldFont=taArea.getFont();
			int style=oldFont.getStyle();
			if(jcbItalic.isSelected()){
				style+=Font.ITALIC;				
				}
				else
				{
				style-=Font.ITALIC;	
				}
			Font newFont=new Font(oldFont.getFontName(),style,oldFont.getSize());
			taArea.setFont(newFont);
		}
	}
	public class MyListenerHelp implements ActionListener{
		public void actionPerformed(ActionEvent e){
			frmAbout=new JFrame("关于");
			frmAbout.setSize(200,100);
			frmAbout.setLocation(400,300);
			JTextArea area1=new JTextArea("制作人 ：邹洪侠\n制作时间： 2014.5.24");
			frmAbout.add(area1);
			frmAbout.setVisible(true);
		}
	}
	public void openText()	//打开
	{
		JFileChooser chooser=new JFileChooser();
		FileNameExtensionFilter filter=new FileNameExtensionFilter("Files","txt","java");
		chooser.setFileFilter(filter);
		chooser.setCurrentDirectory(new File("."));
		int result=chooser.showOpenDialog(TxtEditor.this);
		if(result==JFileChooser.APPROVE_OPTION)
		{
			name=chooser.getSelectedFile().getPath();
			setTitle(name);
			try{
			BufferedReader  in=new BufferedReader(new FileReader(name));
			String line=null;
			String datas="";
			while((line=in.readLine())!=null)
			{
				if(datas=="")
				{
					datas=datas+line;
				}
				else
				{
					datas=datas+"\n"+line;
				}
			}
			taArea.setText(datas);
			in.close();
			}catch(Exception ex)
			{
			}
		}
	}
	public void saveText()    //保存
	{
		if(name==null)
		{
			JFileChooser chooser=new JFileChooser();
			FileNameExtensionFilter filter=new FileNameExtensionFilter("Files","txt","java");
			chooser.setFileFilter(filter);
			chooser.setCurrentDirectory(new File("."));
			int result=chooser.showSaveDialog(TxtEditor.this);
			if(result==JFileChooser.APPROVE_OPTION)
			{
				name=chooser.getSelectedFile().getPath();
				try{
				OutputStream  out=new FileOutputStream(name);
				String datas=taArea.getText();
				out.write(datas.getBytes());
				out.close();
				}catch(Exception ex)
				{
				}
			}
		}
		else
		{
			try{
			OutputStream  out=new FileOutputStream(name);
			String datas=taArea.getText();
			out.write(datas.getBytes());
			out.close();
			}catch(Exception ex)
			{
			}
		}
	}
	public void anotherSaveText()  //另存为
	{
		JFileChooser chooser=new JFileChooser();
		FileNameExtensionFilter filter=new FileNameExtensionFilter("Files","txt","java");
		chooser.setFileFilter(filter);
		chooser.setCurrentDirectory(new File("."));
		int result=chooser.showSaveDialog(TxtEditor.this);
		if(result==JFileChooser.APPROVE_OPTION)
		{
			name=chooser.getSelectedFile().getPath();
			try{
			OutputStream  out=new FileOutputStream(name);
			String datas=taArea.getText();
			out.write(datas.getBytes());
			out.close();
			}catch(Exception ex)
			{
			}
		}
	}
	/*public void showDialog()
	{
		dialog=new JDialog();
		dialog.setSize(300, 200);
		dialog.setLocation(400, 300);
		dialog.setModal(true);
		dialog.setTitle("确认对话框");
		dialog.add(new JLabel("您确实要删除选定文本吗?"),BorderLayout.CENTER);
		dialog.add(new JPanel(),BorderLayout.WEST);
		JButton btnYes=new JButton("确认");
		JButton btnNo=new JButton("取消");
		JPanel panel=new JPanel();
		panel.add(btnYes);panel.add(btnNo);
		dialog.add(panel,BorderLayout.SOUTH);
		dialog.setVisible(true);
		btnYes.addActionListener(new ActionListener()	//确认
		{
			public void actionPerformed(ActionEvent e)
			{
				taArea.replaceRange("",taArea.getSelectionStart(),taArea.getSelectionEnd());
				dialog.setVisible(false);dialog.dispose();
			}
		});
		btnNo.addActionListener(new ActionListener()	//取消
		{
			public void actionPerformed(ActionEvent e)
			{
				dialog.setVisible(false);dialog.dispose();
			}
		});
	}*/
	public static void main(String[] args)throws Exception
	{
		new TxtEditor();
	}
}

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