jlab1201.java

编写的一个简单的计算器小程序

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

class Face extends JFrame{
	JTextField text,textM;
	JButton bBack,bCe,bC;
	JButton bMc,b7,b8,b9,bDiv,bSqrt;
	JButton bMr,b4,b5,b6,bMul,bPen;
	JButton bMs,b1,b2,b3,bSub,bRec;
	JButton bMa,b0,bNeg,bPnt,bAdd,bEql;

	Face(String s){
		super(s);
		this.setVisible(true);
		this.setLayout(new BorderLayout(3,1));

		JPanel pan1=new JPanel();
		JPanel pan2=new JPanel();
		JPanel pan3=new JPanel();

		this.add(pan1,"North");
		this.add(pan2,"Center");
		this.add(pan3,"South");

		pan1.setLayout(new GridLayout(1,1));
		pan2.setLayout(new GridLayout(1,4));
		pan3.setLayout(new GridLayout(4,6));

		pan1.add(text=new JTextField("0.",24));
		text.setHorizontalAlignment(JTextField.RIGHT);

		pan2.add(textM=new JTextField(4));
		pan2.add(bBack=new JButton("Backspace"));
		pan2.add(bCe=new JButton("CE"));
		pan2.add(bC=new JButton("C"));

		pan3.add(bMc=new JButton("MC"));
		pan3.add(b7=new JButton("7"));
		pan3.add(b8=new JButton("8"));
		pan3.add(b9=new JButton("9"));
		pan3.add(bDiv=new JButton("/"));
		pan3.add(bSqrt=new JButton("sqrt"));
		pan3.add(bMr=new JButton("MR"));
		pan3.add(b4=new JButton("4"));
		pan3.add(b5=new JButton("5"));
		pan3.add(b6=new JButton("6"));
		pan3.add(bMul=new JButton("*"));
		pan3.add(bPen=new JButton("%"));
		pan3.add(bMs=new JButton("MS"));
		pan3.add(b1=new JButton("1"));
		pan3.add(b2=new JButton("2"));
		pan3.add(b3=new JButton("3"));
		pan3.add(bSub=new JButton("-"));
		pan3.add(bRec=new JButton("1/x"));
		pan3.add(bMa=new JButton("M+"));
		pan3.add(b0=new JButton("0"));
		pan3.add(bNeg=new JButton("+/-"));
		pan3.add(bPnt=new JButton("."));
		pan3.add(bAdd=new JButton("+"));
		pan3.add(bEql=new JButton("="));
		
		this.pack();
	}
}

class JLab1201 extends Face implements ActionListener{
	private double one=0;
	private String other="";
	private String out="";
	private double r=10;

	JLab1201(){
		super("计算器");

		bBack.addActionListener(this);
		bCe.addActionListener(this);
		bC.addActionListener(this);

		bMc.addActionListener(this);
		b7.addActionListener(this);
		b8.addActionListener(this);
		b9.addActionListener(this);
		bDiv.addActionListener(this);
		bSqrt.addActionListener(this);

		bMr.addActionListener(this);
		b4.addActionListener(this);
		b5.addActionListener(this);
		b6.addActionListener(this);
		bMul.addActionListener(this);
		bPen.addActionListener(this);

		bMs.addActionListener(this);
		b1.addActionListener(this);
		b2.addActionListener(this);
		b3.addActionListener(this);
		bSub.addActionListener(this);
		bRec.addActionListener(this);

		bMs.addActionListener(this);
		b0.addActionListener(this);
		bNeg.addActionListener(this);
		bPnt.addActionListener(this);
		bAdd.addActionListener(this);
		bEql.addActionListener(this);
	}

	public void actionPerformed(ActionEvent e){
		try{
			other=e.getActionCommand().toString();

			if(other=="0"||other=="1"||other=="2"||other=="3"||other=="4"||
				other=="5"||other=="6"||other=="7"||other=="8"||other=="9"
			){
				one=one*r+Double.parseDouble(other);
				text.setText(Double.toString(one));
			}

			if(other=="."){
				r=0.1;
			}

			if(other=="Backspace"){
				one-=one%r;
				text.setText(Double.toString(one));
			}

			if(other=="C"){
				one=0;
				r=10;
				text.setText("0.");
			}

			if(other=="sqrt"){
				one=Math.sqrt(one);
				text.setText(Double.toString(one));
			}

			if(other=="%"){
				one/=100;
				text.setText(Double.toString(one));
			}

			if(other=="+/-"){
				one*=-1;
				text.setText(Double.toString(one));
			}
		}
		catch(Exception ex){
		}
	}

	public static void main(String []args){
		JLab1201 xie=new JLab1201();
	}
}