GUI用户图形界面

/*记事本小练习
 * GUI & IO综合运用
 */

import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class Test33 {
    public static void main(String[] args) {

        MyTest mytest = new MyTest();
        mytest.frameInit(); //运行窗口
    }
}

class MyTest{

    //定义成员变量，包括窗体，文本区域，对话框，File类，菜单等
    private Frame myFrame;  

    private TextArea ta;

    private FileDialog openDialog;
    private FileDialog saveDialog;

    private File f;

    private MenuBar mb ;
    private Menu m1;
    private MenuItem mi1,mi2,mi3;

    MyTest() {

    }

    public void frameInit() { //实现窗体

        myFrame = new Frame("MyEditor");
        myFrame.setBounds(100, 50, 700, 650);

        ta = new TextArea();
        myFrame.add(ta);

        openDialog = new FileDialog(myFrame, "打开文件",  FileDialog.LOAD);
        saveDialog = new FileDialog(myFrame,"保存",FileDialog.SAVE);

        menuInit();  //调用菜单实现方法
        myEvent();  //调用事件

        myFrame.setVisible(true);

    }

    public void menuInit() { //菜单实现

         mb = new MenuBar() ;

         m1 = new Menu("文件");

         mi1 = new MenuItem("打开");
         mi2 = new MenuItem("保存");
         mi3 = new MenuItem("关闭");

         mb.add(m1);
         m1.add(mi1);
         m1.add(mi2);
         m1.add(mi3);

         myFrame.setMenuBar(mb);
    }

    public void myEvent() { //事件

        myFrame.addWindowListener(new WindowAdapter() {  //关闭窗口红叉事件

            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        mi1.addActionListener(new ActionListener() {  //打开事件

            @Override
            public void actionPerformed(ActionEvent e) {

                openDialog.setVisible(true);

                String dirPath = openDialog.getDirectory();
                String name =  openDialog.getFile();

                if(dirPath == null||name ==null)
                    return;

                ta.setText("");

                //System.out.println(dirPath);
                f = new File(dirPath, name);
                String temp = null;
                try {
                    BufferedReader bf = new BufferedReader(new FileReader(f));

                    while((temp = bf.readLine())!=null)
                        ta.append(temp+"\r\n");

                } catch (IOException e1) {

                    e1.printStackTrace();
                }

            }

        });

        mi2.addActionListener(new ActionListener() {  //保存事件

            @Override
            public void actionPerformed(ActionEvent e) {

                saveDialog.setVisible(true);

                String dirPath = saveDialog.getDirectory();
                String name = saveDialog.getFile();

                if(dirPath == null||name ==null)
                    return;

                f = new File(dirPath, name);
                String temp = null;
                try {
                    BufferedWriter bw = new BufferedWriter(new FileWriter(f));

                    String text = ta.getText();

                    bw.write(text);
                    bw.flush();

                } catch (IOException e1) {

                    e1.printStackTrace();
                }

            }

        });

        mi3.addActionListener(new ActionListener() {  //关闭事件

            public void actionPerformed(ActionEvent E) {
                System.exit(0);
            }
        } );
    }

}