使用java GUI编写一个计算BMI的计算器

使用java GUI编写一个计算BMI的计算器

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calc extends JFrame implements ActionListener,KeyListener{

	JTextField txtResult;
	JButton btn0,btn1,btn2,btn3,btn4,btn5,btn6,btn7,btn8,btn9;
	JButton btnAdd,btnSub,btnTimes,btnDiv,btnEquals,btnDot;
	JButton btnClear,btnExit;
	JPanel centerPanel,southPanel;
	double num1=0,num2=0,result=0;
	String opr= "+";
	public Calc() {
		setTitle("计算器2016");
		txtResult = new JTextField("0.0");
		//只读
//		txtResult.setEditable(false);
		
		centerPanel = new JPanel(new GridLayout(4,4,5,5));
		southPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
		add(txtResult,BorderLayout.NORTH);
		txtResult.addKeyListener(this);
		add(centerPanel);
		btn0 = new JButton("0");
		btn1 = new JButton("1");
		btn2 = new JButton("2");
		btn3 = new JButton("3");
		btn4 = new JButton("4");
		btn5 = new JButton("5");
		btn6 = new JButton("6");
		btn7 = new JButton("7");
		btn8 = new JButton("8");
		btn9 = new JButton("9");
		btnAdd = new JButton("+");
		btnSub = new JButton("-");
		btnTimes = new JButton("*");
		btnDiv = new JButton("/");
		btnDot = new JButton(".");
		btnEquals = new JButton("=");
		centerPanel.add(btn7);
		centerPanel.add(btn8);
		centerPanel.add(btn9);
		centerPanel.add(btnDiv);
		centerPanel.add(btn4);
		centerPanel.add(btn5);
		centerPanel.add(btn6);
		centerPanel.add(btnTimes);
		centerPanel.add(btn1);
		centerPanel.add(btn2);
		centerPanel.add(btn3);
		centerPanel.add(btnSub);
		centerPanel.add(btn0);
		centerPanel.add(btnDot);
		centerPanel.add(btnEquals);
		centerPanel.add(btnAdd);
		
		
		
		add(southPanel,BorderLayout.SOUTH);
		btnClear = new JButton("清除");
		btnExit = new JButton("关闭");
		southPanel.add(btnClear);
		southPanel.add(btnExit);
		
		//监听
		btn0.addActionListener(this);
		btn1.addActionListener(this);
		btn2.addActionListener(this);
		btn3.addActionListener(this);
		btn4.addActionListener(this);
		btn5.addActionListener(this);
		btn6.addActionListener(this);
		btn7.addActionListener(this);
		btn8.addActionListener(this);
		btn9.addActionListener(this);
		btnAdd.addActionListener(this);
		btnSub.addActionListener(this);
		btnTimes.addActionListener(this);
		btnDiv.addActionListener(this);
		btnDot.addActionListener(this);
		btnEquals.addActionListener(this);
		btnClear.addActionListener(this);
		btnExit.addActionListener(this);
		
		
		setSize(300, 300);
		setVisible(true);
		setLocationRelativeTo(null);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
	}
	public static void main(String[] args) {
		new Calc();
	}
	public void actionPerformed(ActionEvent e) {
		if(e.getSource()==btnClear){
			txtResult.setText("0");
		}else if(e.getSource()==btnExit){
			System.exit(0);
		}else if(e.getSource()==btn0){
			setText("0");
		}else if(e.getSource()==btn1){
			setText("1");
		}else if(e.getSource()==btn2){
			setText("2");
		}else if(e.getSource()==btn3){
			setText("3");
		}else if(e.getSource()==btn4){
			setText("4");
		}else if(e.getSource()==btn5){
			setText("5");
		}else if(e.getSource()==btn6){
			setText("6");
		}else if(e.getSource()==btn7){
			setText("7");
		}else if(e.getSource()==btn8){
			setText("8");
		}else if(e.getSource()==btn9){
			setText("9");
		}else if(e.getSource()==btnDot){
			setText(".");
		}else if(e.getSource()==btnAdd){
			opr = "+";
			operator();
			//清空内容
			txtResult.setText("");
		}else if(e.getSource()==btnSub){
			opr = "-";
			operator();
			//清空内容
			txtResult.setText("");
		}else if(e.getSource()==btnTimes){
			opr = "*";
			operator();
			//清空内容
			txtResult.setText("");
		}else if(e.getSource()==btnDiv){
			opr = "/";
			operator();
			//清空内容
			txtResult.setText("");
		}else if(e.getSource()==btnEquals){
			operator();
			txtResult.setText(result+"");
			num1=num2=result=0;
		}
		
	}
	public void setText(String s){
		//获取文本框的值
		String str = txtResult.getText().trim();
		//如果文本框里面的值是0，那么初始化为空值
		if(str.equals("" ) || Double.parseDouble(str)==0){
			str = "";
		}
		str += s;
		//设置文本框的值
		txtResult.setText(str);
	}
	public void operator(){
		if(txtResult.getText().equals("")){
			num1=0;
		}else{
			num1 = Double.parseDouble(txtResult.getText().trim());
		}
		System.out.println("num1="+num1+";num2="+num2);
		if(opr.equals("+")){
			result = num1+num2;
		}else if(opr.equals("-")){
			result = num2-num1;
		}else if(opr.equals("*")){
			result = num1*num2;
		}else if(opr.equals("/")){
			result = num2/num1;
		}
		num2=num1;
	}
	String m_temp;
	public void keyPressed(KeyEvent e) {
		m_temp = txtResult.getText();
		
		
	}
	public void keyReleased(KeyEvent e) {
		try{
			Double.parseDouble(txtResult.getText());
		}catch(Exception ex){
			txtResult.setText(m_temp);
		}
	}
	public void keyTyped(KeyEvent e) {
		// TODO Auto-generated method stub
		
	}
}

您好，我是有问必答小助手，您的问题已经有小伙伴解答了，您看下是否解决，可以追评进行沟通哦~

如果有您比较满意的答案 / 帮您提供解决思路的答案，可以点击【采纳】按钮，给回答的小伙伴一些鼓励哦～～

ps:问答VIP仅需29元，即可享受5次/月 有问必答服务，了解详情>>>https://vip.csdn.net/askvip?utm_source=1146287632