java 之GUI

最新推荐文章于 2025-03-02 15:43:23 发布

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程序1：

创建图形化界面：

1.创建frame窗体

2.对窗体进行基本的设置，比如大小，位置，布局

3.定义组件

4.将组件通过窗体的add方法添加到窗体中

5.让窗体显示，通过setVisible(true)

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;

public class AWTDemo {
	public static void main(String[] args) {
		Frame f = new Frame("my awt");//我的窗体
		f.setBounds(300, 400, 300, 400);
		f.setLayout(new FlowLayout());
		Button b = new Button("确定");
		f.add(b);
		f.setVisible(true);
		
	}
}

2.事件监听机制：

事件监听机制的特点：
1，事件源（组件）。
2，事件（Event）。
3，监听器（Listener）。
4，事件处理(引发事件后处理方式)。
事件源：就是awt包或者swing包中的那些图形界面组件。
事件：每一个事件源都有自己特有的对应事件和共性事件。
监听器：将可以触发某一个事件的动作（不只一个动作）都已经封装到了监听器中。
以上三者，在java中都已经定义好了。
直接获取其对象来用就可以了。
我们要做的事情是，就是对产生的动作进行处理。

事件监听流程图：

窗体事件：

class MyWin implements WindowListener
{
//覆盖7个方法。可是我只用到了关闭的动作。
//其他动作都没有用到，可是却必须复写。

}
//因为WindowListener的子类WindowAdapter已经实现了WindowListener接口。
//并覆盖了其中的所有方法。那么我只要继承自Windowadapter覆盖我需要的方法即可。
class MyWin extends WindowAdapter
{
public void windowClosing(WindowEvent e)
{
//System.out.println("window closing---"+e.toString());
System.exit(0);
}
}

import java.awt.*;
import java.awt.event.*;
class AwtDemo 
{
	public static void main(String[] args) 
	{
		Frame f = new Frame("my awt");//窗体
		f.setSize(500,400);
		f.setLocation(300,200);
		f.setLayout(new FlowLayout());
		Button b = new Button("我是一个按钮");
		f.add(b);
		f.setVisible(true);
		//f.addWindowListener(new MyWin());
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e)
		        {
	
		                System.out.println("关了");
		                System.exit(0);
	                }

			public void windowActivated(WindowEvent e)
			{
				
				System.out.println("激活了");
			}
			public void windowOpened(WindowEvent e)
			{
				System.out.println("打开了");
			}
		});
		//System.out.println("Hello World!");
	}
}

class MyWin extends WindowAdapter
{
	public void windowClosing(WindowEvent e)
	{
	
		System.out.println("关了");
		System.exit(0);
	}
}

Action事件：

下面一个程序来说明：

按钮具备退出程序的功能

按钮就是事件源

那么选择哪个监听器呢？

通过关闭窗体示例了解，想要知道哪个组件具备什么样的特有监听器

需要查看该组件对象的功能

通过查阅button的描述，发现按钮支持一个特有监听addActionListener

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class FrameDemo {
	private Frame f;
	private Button b;
	FrameDemo(){
		init();
	}
	public void init() {
		f = new Frame("my awt");
		b = new Button("确定");
		f.setBounds(200,300, 200, 200);
		f.setLayout(new FlowLayout());
		f.add(b);
		myEvent();
		f.setVisible(true);
		
	}
	public  void myEvent() {
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.out.println("窗口关闭");
				System.exit(0);
			}
		});
		b.addActionListener(new ActionListener(){

			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				System.out.println("按钮关闭的");
				System.exit(0);
			}
			
		});
		
	}
	public static void main(String[] args) {
		new FrameDemo();

	}

}

鼠标事件：

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class MouseDemo {
	private Frame f;
	private Button b;
	MouseDemo(){
		init();
	}
	public void init() {
		f = new Frame("my awt");
		b = new Button("确定");
		f.setBounds(200,300, 200, 200);
		f.setLayout(new FlowLayout());
		f.add(b);
		myEvent();
		f.setVisible(true);
		
	}
	public  void myEvent() {
		f.addMouseListener(new MouseAdapter(){
			public void mouseEntered(MouseEvent e){
				System.out.println("鼠标进入窗体");
			}
		});
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.out.println("action is ok");
				
			}
		});
		b.addMouseListener(new MouseAdapter(){
			private int count = 1;
			private int num = 1;
			private int snum =1;
			public void mouseEntered(MouseEvent e){
				System.out.println("mouse in"+(count++));
			}
			public void mouseClicked(MouseEvent e){
				if(e.getClickCount()==2){
					System.out.println("mouse press twice"+(snum++));
				}
			}
			
			
		});
		
	}
	public static void main(String[] args) {
		new MouseDemo();

	}

}

键盘事件：

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
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.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class KeyDemo {
	private Frame f;
	private Button b;
	private TextField t;
	KeyDemo(){
		init();
	}
	public void init() {
		f = new Frame("my awt");
		b = new Button("确定");
		t = new TextField(10);
		f.setBounds(200,300, 200, 200);
		f.setLayout(new FlowLayout());
		f.add(b);
		f.add(t);
		myEvent();
		f.setVisible(true);
		
	}
	public  void myEvent() {
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e)
			{
				System.exit(0);
			}
		});
		//文本框键盘事件
		t.addKeyListener(new KeyAdapter(){
			public void keyPressed(KeyEvent e){
				if(!(e.getKeyCode()>=KeyEvent.VK_0&&e.getKeyCode()<=KeyEvent.VK_9)){
					System.out.println(e.getKeyCode()+"是非法的");
					e.consume();//屏蔽键，不让英文在文本框中显示
				}
			}
			
		});
		b.addKeyListener(new KeyAdapter(){
			public void keyPressed(KeyEvent e)
			{
				if(e.getKeyCode()==KeyEvent.VK_ESCAPE)
					System.exit(0);
				if(e.isControlDown()&&e.getKeyCode()==KeyEvent.VK_ENTER)
					System.out.println("enter and ctrl is run");
				//System.out.println(e.getKeyCode()+"..."+e.getKeyChar());//70...f
				//System.out.println(e.getKeyCode()+"..."+KeyEvent.getKeyText(e.getKeyChar()));//10...Enter
			}
		
		});
		
	}
	public static void main(String[] args) {
		new KeyDemo();

	}

}

列出指定目录内容：

在文本框中输入目录，点击“转到”按钮，将该目录中的文件与文件夹名称列在下面的区域中

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

public class MyWindowDemo {
	private Frame f;
	private TextField tf;
	private Button b;
	private TextArea ta;
	MyWindowDemo(){
		init();
	}
	public  void init() {
		f = new Frame("窗体");
		f.setBounds(300, 400, 600, 500);
		f.setLayout(new FlowLayout());
		tf = new TextField(60);
		b = new Button("转到");
		ta = new TextArea(25,70);
		f.add(tf);
		f.add(b);
		f.add(ta);
		myEvent();
		f.setVisible(true);
		
		
	}
	public  void myEvent() {
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}
		});
		b.addActionListener(new ActionListener(){

			public void actionPerformed(ActionEvent e) {
				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");
					}
				}
				
			}

			
		});
		
	}
	public static void main(String[] args) {
		new MyWindowDemo();

	}

}

dialog对话框，例子程序为上面的程序添加对话框：

import java.awt.*;
import java.awt.event.*;
import java.io.*;
class  MyWindowDemo
{
	private Frame f;
	private TextField t;
	private Button b;
	private TextArea tf;
	private Dialog d;
	private Label l;
	private Button bb;
	MyWindowDemo()
	{
		init();
	}
	public void init()
	{
		f = new Frame("my window");
		f.setBounds(300,150,600,500);
		f.setLayout(new FlowLayout());
		t= new TextField(60);
		b = new Button("转到");
		tf = new TextArea(25,70);

		d = new Dialog(f,"提示信息",true);
		d.setBounds(400,200,300,150);
		d.setLayout(new FlowLayout());
		l= new Label();
		bb = new Button("确定");
		d.add(l);
		d.add(bb);
		
		
		
		f.add(t);
		f.add(b);
		f.add(tf);
		myEvent();
		f.setVisible(true);
	}
	public void myEvent()
	{
		t.addKeyListener(new KeyAdapter(){
		
			public void keyPressed(KeyEvent e)
			{
				if(e.getKeyCode()==KeyEvent.VK_ENTER)
					dir();
			}
		});

		bb.addActionListener(new ActionListener(){
		
			public void actionPerformed(ActionEvent e)
			{
			
				d.setVisible(false);

			}
		});

		d.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e)
			{
				d.setVisible(false);

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

			}
		});
		b.addActionListener(new ActionListener(){
		
			public void actionPerformed(ActionEvent e)
			{
				
				dir();
			}
		});
	}
		private void dir()
		{
			String dirPath = t.getText();
				File dir = new File(dirPath);
				if(dir.exists()&&dir.isDirectory())
				{
					tf.setText("");
					String[] names = dir.list();
					for(String name : names)
					{
						tf.append(name+"\r\n");
					}
				}
				else
				{
					String info="您输入的信息"+dirPath+"有误";
					l.setText(info);
					d.setVisible(true);
				}

		}
	
	public static void main(String[] args) 
	{
		new MyWindowDemo();
	}
}

GUI中的菜单：

Menu中可以包含Menu和MenuItem，MenuBar中可以添加Menu，

Frame中用setMenuBar方法来添加MenuBar

程序：

import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class MenuDemo {
	private Frame f;
	private MenuBar mb;
	private Menu m,mm;
	private MenuItem mi,subItem;
	MenuDemo(){
		init();
	}
	public  void init() {
		f = new Frame("my awt");
		mb = new MenuBar();
		m = new Menu("文件菜单");
		mm = new Menu("子菜单");
		mi = new MenuItem("退出");
		subItem = new MenuItem("子条目");
		f.setBounds(200, 300, 400, 500);
		f.setLayout(new FlowLayout());
		f.setMenuBar(mb);
		mb.add(m);
		m.add(mm);
		m.add(mi);
		mm.add(subItem);
		myEvent();
		f.setVisible(true);
		
	}
	private void myEvent() {
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}
		});
		mi.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e) {
				System.exit(0);
			}
				
		});
		
	}
	public static void main(String[] args) {
		
		new  MenuDemo();
	}

}

练习：打开，保存文件：FileDialog（很重要的练习！！）

package GUI;

import java.awt.FileDialog;
import java.awt.FlowLayout;
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;

public class MenuTest {
	private Frame f;
	private MenuBar bar;
	private Menu FileMenu;
	private MenuItem close,open,save;
	private FileDialog openDialog;
	private FileDialog saveDialog;
	private TextArea ta;
	private File file;
	MenuTest(){
		init();
	}
	public  void init() {
		f= new Frame("my awt");
		bar = new MenuBar();
		FileMenu = new Menu("File");
		close = new MenuItem("close");
		open = new MenuItem("open");
		save = new MenuItem("save");
		ta = new TextArea();
		
		f.setBounds(200, 300, 650, 500);
		 f.setLayout(new FlowLayout());
		 
		 openDialog = new FileDialog(f,"我要打开",FileDialog.LOAD);
		 saveDialog = new FileDialog(f,"我要保存",FileDialog.SAVE);
		
		 
		 bar.add(FileMenu);
		 FileMenu.add(close);
		 FileMenu.add(open);
		 FileMenu.add(save);
		 f.setMenuBar(bar);
		 f.add(ta);
		 myEvent();
		f.setVisible(true);
	}
	public  void myEvent() {
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}
		});
		save.addActionListener(new  ActionListener(){

			public void actionPerformed(ActionEvent e) {
				if(file==null){
					saveDialog.setVisible(true);
					String dirPath = saveDialog.getDirectory();
				     String filePath =saveDialog.getFile();
					 if(dirPath==null || filePath==null)
						 return;
					 file = new File(dirPath,filePath);
				}
				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("保存失败");
			}
			
		}
	
		
		});
		open.addActionListener(new  ActionListener(){

			public void actionPerformed(ActionEvent e) {
				openDialog.setVisible(true);
				String dirpath = openDialog.getDirectory();
				String filepath = openDialog.getFile();
				//System.out.println(dirpath+"...."+filepath);
				if(dirpath==null || filepath==null)
					return;
				ta.setText("");
				File file = new File(dirpath,filepath);
				try{
					BufferedReader bufr = new BufferedReader(new FileReader(file));
					String line = null;
					while((line = bufr.readLine())!=null){
						ta.append(line+"\r\n");
					}
				}catch (IOException e1)
				{
					throw new RuntimeException("读取失败");
				}
				
			}
			
		});
		close.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e)
			{
				System.exit(0);

			}
		
		});
		
		
	}
	public static void main(String[] args) {
		
		new MenuTest();
	}

}