Java实现常规的计算器（网格布局）

àì夳堔傛蜴生んèń 2022-05-28 12:08 134阅读 0赞

计算器的布局比较整齐，利用网格布局排列计算器按钮是一种比较理想的方式，实现的java程序如下：

import java.awt.*;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import javax.swing.*;
    /**
     * 
     * @author IWong
     *
     */
    public class Calculator {
    	public static void main(String[] args) {
    		EventQueue.invokeLater(() -> {
    	         CalculatorFrame frame = new CalculatorFrame();
    	         frame.setTitle("计算器");
    	         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    	         frame.setVisible(true);
    	      });
    	}
    }
    
    class CalculatorFrame extends JFrame{
    	public CalculatorFrame() {
    		add(new CalculatorPanel());
    		pack();
    	}
    	
    }
    
    class CalculatorPanel extends JPanel{
    	private JPanel panel;
    	private JTextField display;
    	private double result;
    	private String lastcommand;
    	private boolean start=true;
    	public CalculatorPanel() {
    		setLayout(new BorderLayout());
    		display=new JTextField();
    		display.setHorizontalAlignment(JTextField.RIGHT);
    		result=0;
    		display.setText(""+result);
    		add(display,BorderLayout.NORTH);
    		ActionListener insert=new InsertAction();
    		ActionListener command=new CommandAction();
    		panel=new JPanel();
    		panel.setLayout(new GridLayout(4,4));
    		addButton("7",insert);
    		addButton("8",insert);
    		addButton("9",insert);
    		addButton("/",command);
    		addButton("4",insert);
    		addButton("5",insert);
    		addButton("6",insert);
    		addButton("*",command);
    		addButton("1",insert);
    		addButton("2",insert);
    		addButton("3",insert);
    		addButton("+",command);
    		addButton("0",insert);
    		addButton(".",insert);
    		addButton("=",command);
    		addButton("+",command);
    		add(panel,BorderLayout.CENTER);	
    	}
    	
    	private void addButton(String s, ActionListener listener) {
    		JButton button=new JButton(s);
    		button.addActionListener(listener);
    		panel.add(button);
    	}
    	
    	private class InsertAction implements ActionListener{
    		public void actionPerformed(ActionEvent event) {
    			String input=event.getActionCommand();
    			if(start){
    				display.setText("");
    				start=false;
    			}
    			display.setText(display.getText()+input);
    		}
    	}
    	private class CommandAction implements ActionListener{
    		public void actionPerformed(ActionEvent event) {
    			String command=event.getActionCommand();
    			if(command.equals("=")){			
    				if(lastcommand.equals("+")) result+=Double.parseDouble(display.getText());			
    				if(lastcommand.equals("-")) result-=Double.parseDouble(display.getText());			
    				if(lastcommand.equals("*")) result*=Double.parseDouble(display.getText());			
    				if(lastcommand.equals("/")) result/=Double.parseDouble(display.getText());
    				display.setText(""+result);
    				start=true;
    			}else{
    				result=Double.parseDouble(display.getText());			
    				lastcommand=command;
    				start=true;
    			}
    		}
    	}
    	
    }