黑马程序员——java学习13（毕22）——GUI

1、GUI

1.1、

java.awt: Abstract Window ToolKit(抽象窗口工具包)需要调用本地系统方法实现功能。跨平台性稍不好，属重量级控件

javax.Swing: 在AWT基础上，建立的一套图形界面系统，其中提供了更多的组件，而且完全由java实现，增强了移植性，属轻量级控件

package learn;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
/*
 * 创建图形化界面
 * 1、创建frame窗体
 * 2、对窗体进行基本设置
 *         比如大小，位置，布局，
 * 3、定义组件
 * 4、将组件通过窗体的add方法添加到窗体中
 * 5、让窗体显示，通过setVisible(true)
 * 
 * 事件监听机制特点
 * 1、事件源
 * 2、事件
 * 3、监听器
 * 4、事件处理
 * 
 * 事件源：就是AWT包或者swing包中的那些图形界面组件
 * 事件：每一个事件源都有特有的对应事件和共性事件
 * 
 * 监听器：将可以触发一个事件的动作（不只一个动作）都已经封装到了监听器中
 * 以上三者，在java中都已经定义好了
 * 直接获取其对象来用就可以了。
 * 我们要做的事情是，就是对产生的动作进行处理
 * 
 * */
public class AwtDemo {
    public static void main(String[] args) {
        Frame f = new Frame("my awt");
        f.setSize(500,400);
        f.setLocation(300,200);
        f.setLayout(new FlowLayout());
        Button b = new Button("我是一个按钮");
        f.add(b);
//        f.addWindowListener(new Mywin());
        //内部类 
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.out.println("我关");
                System.exit(0);
            }
        }
        );
        //设可见边框
        f.setVisible(true);
//        System.out.println("helloworld");
    }    
}
//class MyWin implements WindowListener
//{
//    //覆盖7个方法，可只需要关闭
//    //其他没用到的也得覆写
//}
//因为WindowListener的子类WindowAdapter已经实现了WindowListener接口
//并覆盖了其中的所有方法，那么我只要继承WindowAdapter覆盖我需要的方法既可
class Mywin extends WindowAdapter
{
    public void windowClosing(WindowEvent e)
    {
        System.out.println("WindowClosing");
        System.exit(0);
    }
}

1.2、按钮的监听

package learn;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class FrameDemo {
    //定义图形中所需的组件的引用
    private Frame f;
    private Button but;
    FrameDemo()
    {
    init();    
    }
    public void init()
    {
        f =new Frame("myframe");
        //对frame进行基本设置
        f.setBounds(300,100,600,500);
        f.setLayout(new FlowLayout());
        
        but = new Button("my button");
        //将组件添加到frame中
        f.add(but);
        //加载一下窗体上时间
        myEvent();
        //显示窗体
        f.setVisible(true);
    }
    private void myEvent()
    {
        f.addWindowListener(new WindowAdapter()
        {public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
        //让按钮具备退出程序功能
        //按钮就是事件源
        //通过关闭窗体示例了解到，想要知道哪个组件具备什么样的特有监听器
        //需要查看该组件对象的功能
        //通过查阅Buffon的描述，发现按钮支持一个特有监听addActionListener
        but.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                System.out.println("退出，按钮干的");
                System.exit(0);
            }
        });
    }
    
    public static void main(String[] args) {
        
        new FrameDemo();
    }
}

1.3、鼠标键盘监听

if(e.getClickCount()==2)//监听双击

if(e.isControlDown()&&e.getKeyCode()==KeyEvent.VK_ENTER)//组合键

e.consume();//屏蔽进

package learn;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class MouseAndKey {
    
        //定义图形中所需的组件的引用
        private Frame f;
        private Button but;
        private TextField tf;
        MouseAndKey()
        {
        init();    
        }
        public void init()
        {
            f =new Frame("myframe");
        
            f.setBounds(300,100,600,500);
            f.setLayout(new FlowLayout());
            tf = new TextField(20);
            but = new Button("my button");
            
            f.add(tf);
            f.add(but);
            
            myEvent();
        
            f.setVisible(true);
        }
        private void myEvent()
        {
            f.addWindowListener(new WindowAdapter()
            {public void windowClosing(WindowEvent e)
                {
                    System.exit(0);
                }
            });
            tf.addKeyListener(new KeyAdapter()
            {
                public void keyPressed(KeyEvent e)
                {
                    int code = e.getKeyCode();
                    if(!(code>=KeyEvent.VK_0&&code<=KeyEvent.VK_9))
                    {
                        System.out.println("code是非法");
                        //屏蔽进
                        e.consume();
                    }
                        
                }
            });
            //键盘监听
            but.addKeyListener(new KeyAdapter()
            {
                public void keyPressed(KeyEvent e)
                {
                    if(e.isControlDown()&&e.getKeyCode()==KeyEvent.VK_ENTER)
                        System.out.println("ctrl+enter");
                    //esc
//                    if(e.getKeyCode()==KeyEvent.VK_ESCAPE)
//                        System.exit(0);
//                    System.out.println(KeyEvent.getKeyText(e.getKeyChar())+"......."+e.getKeyCode());
                }
            });
//            but.addActionListener(new ActionListener()
//            {
//                public void actionPerformed(ActionEvent e)
//                {
//                    System.out.println("action ok");
//                }
//            }
//            );
            but.addMouseListener(new MouseAdapter()
            {
                private int count = 1;
                private int clickCount=1;
                public void mouseEntered(MouseEvent e)
                {
                    System.out.println("鼠标进入到该组件"+count++);
                }
                public void mouseClicked(MouseEvent e)
                {
                    if(e.getClickCount()==2)
                    System.out.println("双击动作"+clickCount++);
                }
            });
        }
        public static void main(String[] args) {
            new MouseAndKey();
        }
}

1.4、列出制定目录内容&弹窗

package learn;

import java.awt.Button;
import java.awt.Dialog;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextArea;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;

public class MyWindowDemo {
    private Frame f;
    private TextField tf;
    private Button but;
    private TextArea ta;
    private Dialog d;
    private Label lab;
    private Button okBut;
    MyWindowDemo()
    {
        init();
    }
    public void init()
    {
        f = new Frame("my window");
        f.setBounds(300,100,600,500);
        //流布局,默认布局是边界布局，且居中
        f.setLayout(new FlowLayout());
        tf = new TextField(30);
        but = new Button("转到");
        ta = new TextArea(25,70);
        
        d = new Dialog(f,"提示信息-self",true);
        d.setBounds(400, 200, 240, 150);
        d.setLayout(new FlowLayout());
        lab = new Label();
        okBut = new Button("确定");
        
        d.add(lab);
        d.add(okBut);
        
        
        f.add(tf);
        f.add(but);
        f.add(ta);
        myEvent();
        f.setVisible(true);
        
    
    }
    private void myEvent()
    {
        okBut.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                d.setVisible(false);
            }
        });
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                d.setVisible(false);
            }
        });
        
        tf.addKeyListener(new KeyAdapter()
        {
            public void keyPressed(KeyEvent e)
            {
                if(e.getKeyCode()==KeyEvent.VK_ENTER)
                    showDir();    
            }
        });
        but.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                showDir();
            }
        });
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
    }
    private void showDir()
    {
        String dirPath =tf.getText();
        File dir = new File(dirPath);
        if(dir.exists()&&dir.isDirectory())
        {
            ta.setText("");
            String[] names = dir.list();
            for(String name:names)
            {
                ta.append(name+"
");
            }
        }
        else
        {
            String info = "您输入的信息："+dirPath+"是错误的，请重输";
            lab.setText(info);
            d.setVisible(true);
        }
    }
    public static void main(String[] args) {
        new MyWindowDemo();
    }
    
}

1.5、菜单

打开，保存。

package learn;

import java.awt.FileDialog;
import java.awt.Frame;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class MyMenuDemo {
    private Frame f;
    private MenuBar bar;
    private TextArea ta;
    private Menu fileMenu;
    private MenuItem openItem,saveItem,closeItem;
    private FileDialog openDia,saveDia;
    private File file;
    
    
    MyMenuDemo()
    {
        init();
    }
    public void init()
    {
        f = new Frame("my window");
        f.setBounds(300,100,650,600);

        
        bar = new MenuBar();
        
        ta = new TextArea();
        
        fileMenu = new Menu("文件");
        
        
        openItem = new MenuItem("打开");
        saveItem = new MenuItem("保存");
        closeItem = new MenuItem("退出");
        

        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        fileMenu.add(closeItem);
        bar.add(fileMenu);
        
        f.setMenuBar(bar);
        openDia = new FileDialog(f,"我要打开",FileDialog.LOAD);
        saveDia = new FileDialog(f,"我要打开",FileDialog.SAVE);
        
        f.add(ta);
        myEvent();
        f.setVisible(true);
        
    }
    private void myEvent()
    {
        saveItem.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                //文件不存在才建文件
                if(file == null)
                {
                    saveDia.setVisible(true);
                    String dirPath = saveDia.getDirectory();
                    String fileName = saveDia.getFile();
                    if(dirPath==null||fileName==null)
                        return ;
                
                    file = new File(dirPath,fileName);
                }
                try
                {
                    BufferedWriter bufw = new BufferedWriter(new FileWriter(file));
                    String text =ta.getText();
                    bufw.write(text);
                    //bufw.flush();
                    bufw.close();
                }
                catch(IOException e3)
                {
                    throw new RuntimeException();
                }
            }
        });
        openItem.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                openDia.setVisible(true);
                String dirPath = openDia.getDirectory();
                String fileName = openDia.getFile();
                System.out.println(dirPath+"::"+fileName);
                if(dirPath==null||fileName==null)
                    return ;
                ta.setText("");
                File file = new File(dirPath,fileName);
                try
                {
                    BufferedReader bufr = new BufferedReader(new FileReader(file));
                    String line = null;
                    while((line=bufr.readLine())!=null)
                    {
                        ta.append(line+"
");
                    }
                    bufr.close(); 
                }
                catch(IOException e1)
                {
                    throw new RuntimeException("读取失败");
                }
            }
        });
        closeItem.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                System.exit(0);
            }
        });
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
    }
    
    public static void main(String[] args) {
        new MyMenuDemo();
    }
}