usetextfield.java

Java语言

import java.awt.*;
import java.awt.event.*;
public class UseTextField{
   public static void main(String args[]){
	MyFrame f=new MyFrame();
	f.setSize(330,200);
	f.setBackground(Color.lightGray);
	f.show();
   }
}
class MyFrame extends Frame implements ActionListener{
	TextField tf1,tf2,tf3;
	Label l1,l2;
	public MyFrame(){
	   super("my frame");
	   this.addWindowListener(new WindowAdapter(){
              public void windowClosing(WindowEvent e){
			dispose();
			System.exit(0);
	      }});
	   l1=new Label("请数入两个数：");
	   l2=new Label("              ");
	   tf1=new TextField(5);
	   tf2=new TextField(5);
	   tf3=new TextField("+ - * %");
	   tf3.setForeground(Color.red);
	   tf3.setBackground(Color.cyan);
	   tf3.addActionListener(this);	
	   setLayout(new FlowLayout());
	   add(l1); add(tf1);add(tf2);add(tf3);add(l2);
	}
   public void actionPerformed(ActionEvent e){
      int x=0,y=1;char ch='0';
      if(e.getSource()==tf3){
	x=Integer.parseInt(tf1.getText());
	y=Integer.parseInt(tf2.getText());
	ch=tf3.getSelectedText().charAt(0);
      }
      switch(ch){
         case'+':
	    l2.setText("运算结果："+x+"+"+y+"="+(x+y));break;
         case'-':
	    l2.setText("运算结果："+x+"-"+y+"="+(x-y));break;
         case'*':
	    l2.setText("运算结果："+x+"*"+y+"="+(x*y));break;
         case'%':
	    l2.setText("运算结果："+x+"%"+y+"="+(x%y));break;
      }
   }
}