java之 22天 GUI 图形界面编程(二)-优快云博客

本文介绍两个Java程序实例：一是通过监听键盘事件展示目录列表的窗口应用；二是带有基本文件操作（如打开与保存）的简易记事本程序。

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[size=medium][b]模拟window开打文件[/b][/size]



import java.awt.Button;
import java.awt.Dialog;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextArea;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;

public class MyWinDemo {

	private Frame f;
	private TextField tf;
	private Button btn;
	private TextArea ta;
	private Dialog d;
	private Label lab;
	private Button okbtn;

	MyWinDemo(){
		init();
	}

	private void init(){
		f=new Frame("my Window");
		f.setBounds(300,100,600,500);
		f.setLayout(new FlowLayout());

		tf=new TextField(60);

		btn=new Button("转到");
		ta=new TextArea(25,70);

		d=new Dialog(f,"提示信息-self",true);
		d.setBounds(400,200,250,150);
		d.setLayout(new FlowLayout());

		lab=new Label();
		okbtn=new Button("确定");

		d.add(lab);
		d.add(okbtn);


		f.add(tf);
		f.add(btn);
		f.add(ta);

		myEvent();
		f.setVisible(true);

	}


	private void myEvent() {

		//添加 回车 时候 自动转到
		tf.addKeyListener(new KeyAdapter() {
			@Override
			public void keyPressed(KeyEvent e) {
				// TODO Auto-generated method stub
				if(e.getKeyCode()==KeyEvent.VK_ENTER){
					showDir();
				}
			}
		});
		//确定按钮事件
		okbtn.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				d.setVisible(false);
			}
		});

		d.addWindowListener(new WindowAdapter() {
			@Override
			public void windowClosing(WindowEvent e) {
				// TODO Auto-generated method stub
				d.setVisible(false);
			}

		});

		btn.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				showDir();
			}

		});


		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}

		});

	}
	private void showDir() {
		String dirPath=tf.getText();

		File dir=new File(dirPath);
		if(dir.exists() && dir.isDirectory()){
			ta.setText("");
			String[] names=dir.list();
			for (String name : names) {
				ta.append(name+"\r\n");
				//ta.setText(text);
			}
		}else{
			String info="您输入的信息:"+dirPath+"有误,请重新输入";
			lab.setText(info);
			d.setVisible(true);
		}

		tf.setText("");
	}
	public static void main(String[] args) {
		new MyWinDemo();
	}

}

[size=medium][b]模拟简单记事本[/b][/size]



import java.awt.FileDialog;
import java.awt.Frame;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 * 实现菜单栏
 */
public class MyMenuDemo {


	private Frame f;
	private MenuBar mb;
	private Menu m,subm;
	private MenuItem closeItem,openItem,saveItem,subItem1,subItem;
	private FileDialog openDialog,saveDialog;
	private TextArea ta;
	private File file;

	MyMenuDemo(){
		init();
	}

	private void init(){
		f=new Frame("my Window");
		f.setBounds(300,100,600,500);
		//f.setLayout();

		mb=new MenuBar();
		m=new Menu("文件");

		closeItem=new MenuItem("退出");
		openItem=new MenuItem("打开");
		saveItem=new MenuItem("保存");

		subm=new Menu("新建");
		subItem1=new MenuItem("Web Project");
		subItem=new MenuItem("Java Project");
		subm.add(subItem);
		subm.add(subItem1);

		m.add(subm);
		m.add(openItem);
		m.add(saveItem);
		m.add(closeItem);
		mb.add(m);

		openDialog=new FileDialog(f,"我要打开",FileDialog.LOAD);
		saveDialog=new FileDialog(f,"我要保存",FileDialog.SAVE);

		ta=new TextArea();

		f.add(ta);
		f.setMenuBar(mb);
		myEvent();

		f.setVisible(true);

	}

	private void myEvent() {

		saveItem.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				if(file==null){
					saveDialog.setVisible(true);
					String dirPath=saveDialog.getDirectory();
					String fileName=saveDialog.getFile();
					if(dirPath==null || fileName==null)
						return;
					file=new File(dirPath,fileName);
				}
				try {

					BufferedWriter bufw=new BufferedWriter(new FileWriter(file));

					String text=ta.getText();

					bufw.write(text);
					bufw.close();
				} catch (IOException e2) {
					throw new RuntimeException("保存失败");
				}

			}
		});

		//打开菜单
		openItem.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				openDialog.setVisible(true);
				String dirPath=openDialog.getDirectory();
				String fileName=openDialog.getFile();
				System.out.println(dirPath+"...."+fileName);
				if(dirPath==null || fileName==null)
					return;
				ta.setText("");
				file=new File(dirPath,fileName);
				try {
					BufferedReader bufr=new BufferedReader(new FileReader(file));
					String line=null;
					while((line=bufr.readLine())!=null){
						ta.append(line+"\r\n");
					}
					bufr.close();
				} catch (IOException e2) {
					throw new RuntimeException("打开异常");
				}

			}
		});


		closeItem.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				System.exit(0);
			}
		});

		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}

		});

	}


	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new MyMenuDemo();
	}

}