focusdemo.java

java课程的资料以及实验的代码

import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.GridLayout;

public class FocusDemo extends Frame implements FocusListener {
    TextField tf;
    TextField tf2;
	public FocusDemo()
	{
		tf=new TextField();
		tf2=new TextField();
		this.setLayout(new GridLayout(2,1));
		this.add(tf);
		this.add(tf2);
		tf.addFocusListener(this);
		tf2.addFocusListener(this);
		this.setSize(200,200);
		this.setVisible(true);
		
		
	}
	public void focusGained(FocusEvent e) {
		// TODO Auto-generated method stub
       if(e.getComponent()==tf && !e.isTemporary())
       {
    	   System.out.println("Field have request the focuse");
    	   tf.setText("Focus");
       }
	}

	public void focusLost(FocusEvent e) {
		// TODO Auto-generated method stub
      
		if(e.getComponent()!=tf2 )
		{
			System.out.println("Field have lost focus");
		}
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
      new FocusDemo();
	}

}