170227网络编程-事件处理

Posted 2020-09-01 菜鸟有觉悟要努力了

//本节课学得 使用内部类 外部类 匿名类添加侦听器的方法。
package event;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MyFrame extends JFrame {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	JButton  jbtn;
	JLabel lbl;
	
	public MyFrame(){
		this.setLocation(100,100);
		this.setSize(500,500);
		this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
		
		jbtn=new JButton("测试");
		lbl=new JLabel();
		
		//（1）给按钮注册一个侦听器对象
		jbtn.addActionListener(new FirstButtonListen());
		
		//（2）给按钮注册一个侦听器对象
		/*jbtn.addActionListener(new SecondButtonListen());*/
		
		//（3）利用匿名类实现给按钮添加一个侦听器
		/*jbtn.addActionListener(new ActionListener(){
			@Override
			public void actionPerformed(ActionEvent arg0) {
				// TODO Auto-generated method stub
				System.out.println("hello zhbit");
			}	
		});*/
		
		//（2）利用内部类实现给按钮添加一个侦听器
		//this.addWindowListener(new MyWindowListener());
		
		//（3）使用内部类的方法添加WindowListener监听器
		this.addWindowListener(new WindowListener(){
			@Override
			public void windowActivated(WindowEvent arg0) {
				// TODO Auto-generated method stub
			}
			@Override
			public void windowClosed(WindowEvent arg0) {
				// TODO Auto-generated method stub
				System.out.println("windows is closed!");
			}
			@Override
			public void windowClosing(WindowEvent arg0) {
				// TODO Auto-generated method stub
				System.out.println("windows is closing!");
			}
			@Override
			public void windowDeactivated(WindowEvent arg0) {
				// TODO Auto-generated method stub	
			}
			@Override
			public void windowDeiconified(WindowEvent arg0) {
				// TODO Auto-generated method stub	
			}
			@Override
			public void windowIconified(WindowEvent arg0) {
				// TODO Auto-generated method stub
			}
			@Override
			public void windowOpened(WindowEvent arg0) {
				// TODO Auto-generated method stub
				lbl.setText("hello 我待会会记录坐标");
			}
		});
		
		this.addMouseMotionListener(new MouseMotionListener(){

			@Override
			public void mouseDragged(MouseEvent e) {
				// TODO Auto-generated method stub
				
			}
			@Override
			public void mouseMoved(MouseEvent e) {
				// TODO Auto-generated method stub
				int x=e.getX();
				int y=e.getY();
				lbl.setText("我的位置是x="+x+"，"+"y="+y+"。");
			}
			
		});
		
		this.add(jbtn);
		this.add(lbl);
		this.setLayout(new FlowLayout());
		this.setVisible(true);
		
	}
	public static void main(String[] args){
		new MyFrame();
	}
	
	//（2）利用内部类实现给按钮添加一个侦听器
	/*class SecondButtonListen implements ActionListener{
		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			System.out.println("hello the second way");
		}
	}*/
	
	//（2）利用内部类实现WindowListener监听
	/*class MyWindowListener extends WindowAdapter{
		@Override
		public void windowClosed(WindowEvent arg0) {
			// TODO Auto-generated method stub
			System.out.println("windows is closed!!!!");
			super.windowClosed(arg0);
		}
	}*/
}
	//（1）创建一个Action类型的侦听器类  外部类
	class FirstButtonListen implements ActionListener{
		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			System.out.println("hello the first way");
		}
		
	}

 

课后习题
习题：利用图形界面编写一个简单的文本编辑器，包含一个文本域和一个保存按钮。单击保存按钮将文本域（TextArea)中的内容保存到一个文本文件mytext.txt中。
提示：
使用TextArea的getText()方法可以获得文本域中的内容。
使用内部类定义事件监听器，实现事件监听器接口ActionListener。
可使用fileWriter的Write(String str, int off, int len)方法将内容写入文件。

package event;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;

public class test1 extends JFrame {
	JButton jb;
	JTextArea jta;
	public test1(){
		this.setLocation(200,200);
		this.setSize(500,500);
		
		jta=new JTextArea(5,20);
		jta.setLineWrap(true);
		jb=new JButton("保存");
		
		
		jb.addActionListener(new ActionListener(){
			@Override
			public void actionPerformed(ActionEvent arg0) {
				// TODO Auto-generated method stub
				try {
					getJta();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
		});
		
		this.addWindowListener(new WindowListener(){

			@Override
			public void windowActivated(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowClosed(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowClosing(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowDeactivated(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowDeiconified(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowIconified(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}

			@Override
			public void windowOpened(WindowEvent e) {
				// TODO Auto-generated method stub
				
			}
			
		});
		
		this.add(jta);
		this.add(jb);
		this.setLayout(new FlowLayout());
		this.setVisible(true);
	}
	void getJta() throws IOException{
		String t;
		t=jta.getText();
		System.out.println(t);
		write(t,0,t.length());
	}
	
	public void write(String str,int off,int len) throws IOException{
		String path="D://mytext.txt";
		FileOutputStream fs=new FileOutputStream(path);
		OutputStreamWriter opsw=new OutputStreamWriter(fs);	
		opsw.write(str);	
		opsw.close();
		fs.close();
	}

	public static void main(String[]args){
		new test1();
	}
}