JAVA基础-GUI

Frame f = new Frame("my window");
f.setLayout(new FlowLayout());
f.setSize(500,400);//设置窗体大小
f.setLocation(300,200);//设置窗体出现在屏幕的位置
f.setVisible(true); //设置窗口可见性

import java.awt.*;
import java.awt.event.*;
import java.io.*;
class Test {
	private Frame f;
	private TextField tf;
	private Button but;
	private TextArea ta;

	private Dialog d;
	private Label lab;
	private Button okBut;

	Test() {
		init();
	}

	public void init() {
		f = new Frame("my window");
		f.setBounds(300,100,600,500);
		f.setLayout(new FlowLayout());
		tf = new TextField(60);
		but = new Button("转到");
		ta = new TextArea(25,70);
		d = new Dialog(f,"提示信息-self",true);
		d.setBounds(400,200,240,150);
		d.setLayout(new FlowLayout());
		lab = new Label();
		okBut = new Button("确定");
		d.add(lab);
		d.add(okBut);
		f.add(tf);
		f.add(but);
		f.add(ta);
		myEvent();
		f.setVisible(true);
	}

	private void myEvent() {
		okBut.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				d.setVisible(false);
			}
		});
		d.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				d.setVisible(false);
			}
		});
		tf.addKeyListener(new KeyAdapter() {
			public void keyPressed(KeyEvent e) {
				if(e.getKeyCode()==KeyEvent.VK_ENTER)
					showDir();
			}
		});
		but.addActionListener(new ActionListener() {
			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");
			}
		} else {
			String info = "输入信息错误，请重输";
			lab.setText(info);
			d.setVisible(true);
		}
	}
	public static void main(String[] args) {
		new Test();
	}
}

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

class Test {

	private Frame f;
	private MenuBar mb;
	private Menu m,subMenu;
	private MenuItem closeItem,subItem;

	Test(){
		init();
	}
	
  public void init(){
		f = new Frame("my window");
		f.setBounds(300,100,500,600);
		f.setLayout(new FlowLayout());
		mb = new MenuBar();
		m = new Menu("文件");
		subMenu = new Menu("子菜单");
		subItem = new MenuItem("子条目");
		closeItem = new MenuItem("退出");
		subMenu.add(subItem);
		m.add(subMenu);
		m.add(closeItem);
		mb.add(m);
		f.setMenuBar(mb);
		myEvent();
		f.setVisible(true);
	}
	private void myEvent() {
		closeItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				System.exit(0);
			}
		});
		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);	
			}
		});
	}
	public static void main(String[] args) {
		new Test();
	}
}

package mymenu;
import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class Test {
	private Frame f;
	private MenuBar bar;
	private TextArea ta;
	private Menu fileMenu;
	private MenuItem openItem,saveItem,closeItem;
	private FileDialog openDia,saveDia;
	private File file;
	Test() {
		init();
	}
	public void init() {
		f = new Frame("my window");
		f.setBounds(300,100,650,600);
		bar = new MenuBar();
		ta = new TextArea();
		fileMenu = new Menu("文件");
		openItem = new MenuItem("打开");
		saveItem = new MenuItem("保存");
		closeItem = new MenuItem("退出");
		fileMenu.add(openItem);
		fileMenu.add(saveItem);
		fileMenu.add(closeItem);
		bar.add(fileMenu);
		f.setMenuBar(bar);
		openDia = new FileDialog(f,"我要打开",FileDialog.LOAD);
		saveDia = new FileDialog(f,"我要保存",FileDialog.SAVE);
		f.add(ta);
		myEvent();
		f.setVisible(true);
	}
	private void myEvent() {
		saveItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if(file==null) {
					saveDia.setVisible(true);
					String dirPath = saveDia.getDirectory();
					String fileName = saveDia.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.flush();
					bufw.close();
				} catch (IOException ex) {
					throw new RuntimeException();
				}
			}
		});
		openItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				openDia.setVisible(true);
				String dirPath = openDia.getDirectory();
				String fileName = openDia.getFile();
				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 ex) {
					throw new RuntimeException("读取失败");
				}
			}
		});
		closeItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				System.exit(0);
			}
		});
		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);	
			}
		});
	}
	public static void main(String[] args) {
		new Test();
	}
}