appgraphinout.java

利用SWT图形界面进行输入输出

import java.awt.*;
import java.awt.event.*;
public class AppGraphInOut {
	public static void main(String args[]){
		new AppFrame();
		}
	}
class AppFrame extends Frame
{
	
	TextField in = new TextField(10);
	Button btn = new Button("求平方");
	Label out = new Label("用于显示结果的标签");
	
public AppFrame()
{
	setLayout(new FlowLayout());
	add(in);
	add(btn);
	add(out);
	btn.addActionListener(new BtnActionAdapter());
	setSize(400,100);
	show();
		
}
class BtnActionAdapter implements ActionListener
{
	public void actionPerformed(ActionEvent e)
	{
		String s = in.getText();
		double d = Double.parseDouble(s);
		double sq = d*d;
		out.setText(d+"的平方根:"+sq);
		
		
	}
}
}