package 小程序;
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
public class Sum extends Applet implements ActionListener {
TextField text1, text2, text3;
Label lb1, lb2, lb3;
public void init() {
text1 = new TextField(25);
text2 = new TextField(25);
text3 = new TextField(25);
lb1 = new Label("请输入第一个整数:");
lb2 = new Label("请输入第二个整数:");
lb3 = new Label("他们的和:");
add(lb1);
add(text1);
add(lb2);
add(text2);
add(lb3);
add(text3);
text1.addActionListener(this);
text2.addActionListener(this);
}
public void paint(Graphics g) {
g.drawString("输出2个数,如果他们的和大于5,则按回车键输出他们的和", 10, 100);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == text1 || e.getSource() == text2
|| e.getSource() == text3) {
int number1, number2, sum;
try {
number1 = Integer.valueOf(text1.getText()).intValue();
number2 = Integer.valueOf(text2.getText()).intValue();
sum = number1 + number2;
if (sum > 5) {
text3.setText("" + sum);
}
} catch (NumberFormatException event) {
text3.setText("请输入整数");
}
} else {
System.exit(0);
}
}
}
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