有很多時候發現視窗不能關閉，其實很簡單的，只要加上下面背景綠色部分加上

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) 

package Button;
import java.awt.*; 

import java.awt.event.*;  

import javax.swing.JFrame;




public class MyFrame extends JFrame{  

    Button myButton; 

    TextArea myTextArea; 

    int count;
    
//    Frame f;

	public static void main(String[] args) {

	   MyFrame myF = new MyFrame(); 


	   myF.setSize(300,300); 

	   myF.setVisible(true); 

	  myF.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 

		
	}



    public MyFrame(){ 

      super("Inner Class Frame"); 

     myButton = new Button("click me"); 

     myTextArea = new TextArea();  

     add(myButton,BorderLayout.CENTER);  

     add(myTextArea,BorderLayout.NORTH); 

     ButtonListener bList = new ButtonListener();  

     myButton.addActionListener(bList);  

     }  


 class ButtonListener implements ActionListener{  

   public void actionPerformed(ActionEvent e){  

   count++; 

     myTextArea.setText("button clicked" +  

         count + "times"); 

   

     }// end of innerclass ButtonListener 

 }
}