AWT窗体

package wo;
import java.awt.*;
import java.awt.event.*;

public class Ex4 extends WindowAdapter implements ActionListener{

	/**
	 * @param args
	 */
	
	Frame myframe;
	Label lab;
	TextField mytext;
	Button mybt;
	public class mykey extends KeyAdapter{
		//
		public void keyPressed(KeyEvent e){
			if(e.getKeyChar()<'0'||e.getKeyChar()>'9')
				lab.setText("你输入了非数字键");
			else
				lab.setText("你输入了数字键");
		}
	}
	public Ex4(){
		myframe=new Frame("awt实例");
		mykey ky=new mykey();
		lab=new Label("你好，世界");
		mytext=new TextField("请在这里填写内容");
		mybt=new Button("清空内容");
		myframe.add(lab);
		myframe.add(mytext);
		myframe.add(mybt);
		myframe.setSize(200,200);
		myframe.setLayout(new FlowLayout());
		//增加监听器，事件响铃对象是自己
		myframe.addWindowListener(this);
		//为按钮添加监听器
		mybt.addActionListener(this);
		//为文本添加监听器
		mytext.addKeyListener(ky);
		myframe.setVisible(true);
	}
	//覆盖父类中窗口关闭方法
	public void windowClosing(WindowEvent e){
		myframe.dispose();
	}
	public void actionPerformed(ActionEvent e){
		if(e.getSource()==mybt)
			mytext.setText(null);
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new Ex4();
	}

}