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import java.awt.Container;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JComboBox;
import javax.swing.JButton;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
class TestCal extends JFrame
{
JTextField []t = {
new JTextField(5),
new JTextField(5),
new JTextField(5)
};
JButton b = new JButton("=");
String []s = {"加法运算:+","减法运算:-","乘法运算:x","除法运算:÷"};
TestCal()
{
super("简单计算器!");
//this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//this.setSize(320,120);
JComboBox cb = new JComboBox(s);
Container c = this.getContentPane();
c.setLayout(new FlowLayout(FlowLayout.LEFT));
t[0].setEditable(true);
t[1].setEditable(true);
t[2].setEditable(false);
c.add(t[0]);
c.add(cb);
c.add(t[1]);
c.add(b);
c.add(t[2]);
c.setVisible(true);
b.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent e)
{
//JButton b = (JButton)e.getSource();
double num1,num2,sum;
if(e.getSource()=="+")
{
num1 = Double.parseDouble(t[0].getText());
num2 = Double.parseDouble(t[1].getText());
sum = num1+num2;
t[2].setText(String.valueOf(sum));
}
if(e.getSource()=="-")
{
num1 = Double.parseDouble(t[0].getText());
num2 = Double.parseDouble(t[1].getText());
sum = num1-num2;
t[2].setText(String.valueOf(sum));
}
if(e.getSource()=="x")
{
num1 = Double.parseDouble(t[0].getText());
num2 = Double.parseDouble(t[1].getText());
sum = num1*num2;
t[2].setText(String.valueOf(sum));
}
if(e.getSource()=="÷")
{
num1 = Double.parseDouble(t[0].getText());
num2 = Double.parseDouble(t[1].getText());
sum = num1/num2;
t[2].setText(String.valueOf(sum));
}
}
});
}
public static void main(String args[]){
TestCal tc=new TestCal();
tc.setSize(500,300);
tc.setVisible(true);
}
}
import java.awt.Container;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JComboBox;
import javax.swing.JButton;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
class TestCal extends JFrame
{
JTextField []t = {
new JTextField(5),
new JTextField(5),
new JTextField(5)
};
JButton b = new JButton("=");
String []s = {"加法运算:+","减法运算:-","乘法运算:x","除法运算:÷"};
TestCal()
{
super("简单计算器!");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//this.setSize(320,120);
final JComboBox cb = new JComboBox(s);
Container c = this.getContentPane();
c.setLayout(new FlowLayout(FlowLayout.LEFT));
t[0].setEditable(true);
t[1].setEditable(true);
t[2].setEditable(false);
c.add(t[0]);
c.add(cb);
c.add(t[1]);
c.add(b);
c.add(t[2]);
c.setVisible(true);
//b.addItemListener(new ItemListener()
b.addActionListener(new ActionListener()
{
//public void itemStateChanged(ItemEvent e)
public void actionPerformed(ActionEvent e)
{
//JButton b = (JButton)e.getSource();
double num1,num2;
num1 = Double.parseDouble(t[0].getText());
num2 = Double.parseDouble(t[1].getText());
switch((cb.getSelectedItem()).toString())
{
case("加法运算:+"):
{
t[2].setText(String.valueOf(num1+num2));
break;
}
case("减法运算:-"):
{
t[2].setText(String.valueOf(num1-num2));
break;
}
case("乘法运算:x"):
{
t[2].setText(String.valueOf(num1*num2));
break;
}
case("除法运算:÷"):
{
if(num2!=0l)
t[2].setText(String.valueOf(num1/num2));
else
JOptionPane.showMessageDialog(TestCal.this,"分母不能为零!", "系统信息", JOptionPane.ERROR_MESSAGE);
break;
}
}
}
});
}
public static void main(String args[]){
TestCal tc=new TestCal();
tc.setSize(500,300);
tc.setVisible(true);
}
}