package mini;import java.awt.*;
import java.awt.event.*;import javax.swing.*;public class Mini extends JFrame implements KeyListener
{
JTextField t1;
JTextField t2;
JTextField t3;
public Mini()
{
setTitle("啊");
setBounds(100,100,250,300);
setResizable(false);
JPanel p=new JPanel();
p.setLayout(new GridLayout(3,1,2,2));
GridBagConstraints c = new GridBagConstraints();
//1
t1=new JTextField();
t1.setHorizontalAlignment(t1.CENTER);
t1.setEditable(false);
p.add(t1);
//2
t2=new JTextField();
t2.setHorizontalAlignment(t2.RIGHT);
addKeyListener(this);
p.add(t2);
setContentPane(p);
//3
t3=new JTextField();
t3.setHorizontalAlignment(t3.RIGHT);
t3.setEditable(false);
p.add(t3);
setContentPane(p);
//Container con=getContentPane();
//组件听。。
}
public static void main(String[] arguments)
{
Mini mm=new Mini();
mm.setVisible(true);
}
public void keyPressed(KeyEvent e)
{
try{
if(e.getKeyChar()=='\n')//回车
{
String a=t2.getText();
int i;
if(a.indexOf("+")!=-1)
{
i=a.indexOf("+");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String sum=Float.toString(a1+a2);
t3.setText(sum);
}
if(a.indexOf("-")!=-1)
{
i=a.indexOf("-");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String subtration=Float.toString(a1-a2);
t3.setText(subtration);
}
if(a.indexOf("*")!=-1)
{
i=a.indexOf("*");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String ride=Float.toString(a1*a2);
t3.setText(ride);
}
if(a.indexOf("/")!=-1)
{
i=a.indexOf("/");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String division=Float.toString(a1*a2);
t3.setText(division);
if(a2==0)
{
t1.setText("分母不能为0");
}
}
else
t1.setText("输入有错");
}
else
{
t1.setText("");
t2.setText("");
t3.setText("");
}
}
catch(Exception ev)
{
t1.setText("输入错误");
}
}
public void keyReleased(KeyEvent arg0) {
// TODO 自动生成方法存根
}
public void keyTyped(KeyEvent arg0) {
// TODO 自动生成方法存根
}
}
import java.awt.event.*;import javax.swing.*;public class Mini extends JFrame implements KeyListener
{
JTextField t1;
JTextField t2;
JTextField t3;
public Mini()
{
setTitle("啊");
setBounds(100,100,250,300);
setResizable(false);
JPanel p=new JPanel();
p.setLayout(new GridLayout(3,1,2,2));
GridBagConstraints c = new GridBagConstraints();
//1
t1=new JTextField();
t1.setHorizontalAlignment(t1.CENTER);
t1.setEditable(false);
p.add(t1);
//2
t2=new JTextField();
t2.setHorizontalAlignment(t2.RIGHT);
addKeyListener(this);
p.add(t2);
setContentPane(p);
//3
t3=new JTextField();
t3.setHorizontalAlignment(t3.RIGHT);
t3.setEditable(false);
p.add(t3);
setContentPane(p);
//Container con=getContentPane();
//组件听。。
}
public static void main(String[] arguments)
{
Mini mm=new Mini();
mm.setVisible(true);
}
public void keyPressed(KeyEvent e)
{
try{
if(e.getKeyChar()=='\n')//回车
{
String a=t2.getText();
int i;
if(a.indexOf("+")!=-1)
{
i=a.indexOf("+");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String sum=Float.toString(a1+a2);
t3.setText(sum);
}
if(a.indexOf("-")!=-1)
{
i=a.indexOf("-");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String subtration=Float.toString(a1-a2);
t3.setText(subtration);
}
if(a.indexOf("*")!=-1)
{
i=a.indexOf("*");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String ride=Float.toString(a1*a2);
t3.setText(ride);
}
if(a.indexOf("/")!=-1)
{
i=a.indexOf("/");
float a1=Float.parseFloat(a.substring(0,i));
float a2=Float.parseFloat(a.substring(i+1));
String division=Float.toString(a1*a2);
t3.setText(division);
if(a2==0)
{
t1.setText("分母不能为0");
}
}
else
t1.setText("输入有错");
}
else
{
t1.setText("");
t2.setText("");
t3.setText("");
}
}
catch(Exception ev)
{
t1.setText("输入错误");
}
}
public void keyReleased(KeyEvent arg0) {
// TODO 自动生成方法存根
}
public void keyTyped(KeyEvent arg0) {
// TODO 自动生成方法存根
}
}
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