利用awt做简单的加法计算器

 

 

package key.aaa;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/*建立窗体，添加两个文本框，两个标签，标签是加和等于，文本框由用户输入，为文本框添加键盘事件监听器，获取
* 输入的数字，添加一个单击按钮，用一个if语句，如果单击按钮则触发相加，*/
public class keypress {
private static void createAndShowGUI() {
JFrame f = new JFrame("KeyEvent");
f.setLayout(new FlowLayout());
f.setSize(400,300);
f.setLocation(100,200);
JTextField tf = new JTextField(10);
f.add(tf);
JLabel label1 =new JLabel();
f.add(label1);
label1.setText("+");
JTextField tf2 = new JTextField(10);
f.add(tf2);
JLabel label2 = new JLabel();
f.add(label2);
label2.setText("=");
JLabel label3 = new JLabel();
f.add(label3);

JButton b = new JButton("计算");

f.add(b);
// b.setLocation(20,29);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
tf.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
char k1 = e.getKeyChar();
}
});
tf2.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
char k2 = e.getKeyChar();
}
});
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(tf!=null&&tf2!=null) {
int s = Integer.valueOf(tf.getText());
int y = Integer.valueOf(tf2.getText());
int x = s+y;
String ss = String.valueOf(x);
label3.setText(ss);
}
}
});

}
public static void main(String[] args) {
createAndShowGUI();
}
}