如何在运行结果的第二三个文本框之间加上等号？

Question

import java.awt.;
import java.awt.event.;
import javax.swing.;
public class Xiti8_5
{ public static void main(String args[])
{ ComputerFrame fr=new ComputerFrame();
fr.setTitle("计算");
}
}
class ComputerFrame extends JFrame implements ActionListener
{ JTextField text1,text2,text3;
JButton button1,button2,button3,button4;
JLabel label;
public ComputerFrame()
{setLayout(new FlowLayout());
text1=new JTextField(10);
text2=new JTextField(10);
text3=new JTextField(10);
label=new JLabel(" ",JLabel.CENTER);
label.setBackground(Color.green);
add(text1);
add(label);
add(text2);
add(text3);
button1=new JButton("加");
button2=new JButton("减");
button3=new JButton("乘");
button4=new JButton("除");
add(button1);
add(button2);
add(button3);
add(button4);
button1.addActionListener(this);
button2.addActionListener(this);
button3.addActionListener(this);
button4.addActionListener(this);
setSize(400,320);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
validate();
}
public void actionPerformed(ActionEvent e)
{ double n;
if(e.getSource()==button1)
{ double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1+n2;
text3.setText(String.valueOf(n));
label.setText("+");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button2)
{ double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1-n2;
text3.setText(String.valueOf(n));
label.setText("-");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button3)
{double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1n2;
text3.setText(String.valueOf(n));
label.setText("*");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button4)
{double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1/n2;
text3.setText(String.valueOf(n));
label.setText("/");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
validate();
}
}

Answer 1

跟加其他组件一样的，你新建一个lable组件，然后放在它们之间，控制好显示的位置就好了哦。