jframetest.java

java关于Swing的一些简单实例

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class JFrameTest extends JFrame implements ActionListener{
	private JTextField jtf1,jtf2,jtf3;
	private JRadioButton jrb1,jrb2,jrb3,jrb4; 
	public JFrameTest(){
		super("四则运算");
		//this.setLayout(new FlowLayout());
		jtf1=new JTextField ();
		jtf2=new JTextField ();
		jtf3=new JTextField ();
		
		jrb1=new JRadioButton("+");
		jrb1.addActionListener(this);
		jrb2=new JRadioButton("-");
		jrb2.addActionListener(this);
		jrb3=new JRadioButton("*");
		jrb3.addActionListener(this);
		jrb4=new JRadioButton("/");
		jrb4.addActionListener(this);
		
		ButtonGroup bg=new ButtonGroup();
		bg.add(jrb1);
		bg.add(jrb2);
		bg.add(jrb3);
		bg.add(jrb4);
		
		Container con=this.getContentPane();
		con.setLayout(new FlowLayout());
		JPanel Jp=new JPanel(new GridLayout(5,1));
		Jp.add(new JLabel("操作数1："));
		Jp.add(jtf1);
		Jp.add(new JLabel(""));
		Jp.add(new JLabel("操作数2："));
		Jp.add(jtf2);
		
		JPanel Jp2=new JPanel(new GridLayout(4,1,2,2));
		Jp2.add(jrb1);
		Jp2.add(jrb2);
		Jp2.add(jrb3);
		Jp2.add(jrb4);
		
		JPanel Jp3=new JPanel(new GridLayout(2,1,2,10));
		Jp3.add(new JLabel("        结果:           "));
		Jp3.add(jtf3);
		
		con.add(Jp);
		con.add(Jp2);
		con.add(Jp3);
		
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		//this.setSize(300, 200);
		pack();
		setVisible(true);
	}
	
	public void actionPerformed(ActionEvent e){
		if(e.getSource()==jrb1){
			caculate("+");
		}
		if(e.getSource()==jrb2){
			caculate("-");
		}
		if(e.getSource()==jrb3){
			caculate("*");
		}
		if(e.getSource()==jrb4){
			caculate("/");
		}
	}
	
	public void caculate(String s){
		try{
			double d1=Double.parseDouble(jtf1.getText());
			double d2=Double.parseDouble(jtf2.getText());
			if(s.equals("+")){
				jtf3.setText(String.valueOf(d1+d2));
				saveFile(s);
			}
			if(s.equals("-")){
				jtf3.setText(String.valueOf(d1-d2));
				saveFile(s);
			}
			if(s.equals("*")){
				jtf3.setText(String.valueOf(d1*d2));
				saveFile(s);
				}
			if(s.equals("/")){
				jtf3.setText(String.valueOf(d1/d2));
				saveFile(s);
			}
		}
		catch(Exception ex){
			jtf3.setText("输入错误");
		}
	}
	
	public void saveFile(String str){
		try{
		BufferedWriter bfw=new BufferedWriter(new FileWriter("cal.txt",true));
		bfw.write(jtf1.getText()+str+jtf2.getText()+"="+jtf3.getText());
		bfw.newLine();
		bfw.flush();
                bfw.close();
		}
		catch(IOException ie){
		}
	}
	public static void main(String[] args) {
		JFrameTest jf=new JFrameTest();

	}
	

}