myawtcalculartor.java

贪食蛇的实现源码

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



	
	class CalculatorPanel extends Panel implements ActionListener{
	    private TextField display;
	    private double arg=0;
	    private String op="=";
	    private boolean start=true;
	    
		public CalculatorPanel(){
			setLayout(new BorderLayout());
			display=new TextField("0");
			display.setEditable(false);//??
			add(display,"North");
			
			Panel p=new Panel();
			p.setLayout(new GridLayout(4,4));
			String buttons="789/456*123-0.=+";//妙哉！！
			for(int i=0;i<buttons.length();i++)
			addButton(p,buttons.substring(i,i+1));
			add(p,"Center");
			
		}
		private void addButton(Container c,String s){
			Button b=new Button(s);
			c.add(b);
			b.addActionListener(this);
		}
		public void actionPerformed(ActionEvent evt){
			String s=evt.getActionCommand();
			if('0'<=s.charAt(0) && s.charAt(0)<='9' || s.equals(".")){
				if(start)  display.setText(s);
				else display.setText(display.getText()+s);
				start=false;
			}
			else{
				if(start){
					if(s.equals("-")){
						display.setText(s);start=false;
					}
					else op=s;
				}
				else{
					double x=Double.parseDouble(display.getText());
					calculate(x);
					op=s;
					start=true;
				}
			}
		}
		public void calculate(double n){
			if(op.equals("+")) 
				arg +=n;
			else if(op.equals("-"))
				arg -=n;
			else if(op.equals("*"))
			    arg *=n;
		    else if(op.equals("/"))  
		    	arg /=n;
			else if(op.equals("="))
			    arg=n;
			display.setText(""+arg);
		}
	}
 
		class CalculatorFrame extends Frame{
			
			public CalculatorFrame(){
				setTitle("Calculator");
				setSize(200,200);
				addWindowListener(new WindowAdapter(){
					public void windowClosing(WindowEvent e){
						System.exit(0);
					}
				});
				this.add(new CalculatorPanel());
			}
		}
 

	public class MyAWTCalculartor{
		public static void main(String args[]){
			Frame frame=new CalculatorFrame();
			frame.setVisible(true);
		}
	}