GUI学习记录1

1. Awt小程序 ：

import java.awt.*; public class testFrame { public static void main(String[] args) { Frame f = new Frame(); f.setName("frame"); f.setSize(500, 600); f.add(new Button("hello")); f.setVisible(true); try{ Thread.sleep(5000); }catch(Exception e){ e.printStackTrace(); } f.dispose(); } }

2 java的事件处理机制

三个重要概念：

事件：用户对组件的一个操作

事件源：发生事件的组件

事件处理器：某个java类中负责处理事件的成员方法

事件分类：

按事件的物理操作和GUI组件的表现效果进行分类：

MouseEvent,WindowEvent,ActionEvent

一个事件监听器对象负责处理一类事件

一类事件的每一种方法发生情况，分别由事件监听器对象中的一个方法具体实现

在事件源和事件监听器对象中进行约定的接口类（事件监听接口）

事件监听器接口类名称与事件类的名称是相对应的

如果要处理发生在GUI组件上的XXXEvent时间的处理通用流程：

1.编写一个实现了XXXListener接口的事件监听器类；

2.xxxListener类中的用于处理事件情况的方法中，编写处理代码

3.调用组件的addxxxListener方法，将类xxxListener创建的实例对象注册到GUI组件上

import java.awt.*; public class testFrame { public static void main(String[] args) { Frame f = new Frame(); f.setName("frame"); f.setSize(500, 600); f.add(new Button("hello")); f.setVisible(true); f.addWindowListener(new MyListener()); //注册窗口监听对象 } } import java.awt.event.WindowEvent; import java.awt.event.WindowListener; import java.awt.Window; public class MyListener implements WindowListener { @Override public void windowActivated(WindowEvent e) { } @Override public void windowClosed(WindowEvent e) { } @Override public void windowClosing(WindowEvent e) { e.getWindow().setVisible(false); ((Window)e.getComponent()).dispose(); //dispose方法在java.awt.Window包中 //需要把getComponet转换为window类型才能调用dispose方法 } @Override public void windowDeactivated(WindowEvent e) { } @Override public void windowDeiconified(WindowEvent e) { } @Override public void windowIconified(WindowEvent e) { } @Override public void windowOpened(WindowEvent e) { } } //以上各方法都需要写出来，都必须对接口方法进行实现

3.方法适配器

JDK中提供了大多数事件监听接口最简单的实现类

用事件适配器来处理事件，可以简化事件监听器来编写

监视器，适配器类在awt.event包中

只要继承了WindowAdapter，就不需要全部写出上面程序中七个方法，只需要写出覆 盖的方法

解决适配器思路：

-方法没有被调用？还是方法中的程序代码的执行问题？

-方法名写错了？还是没有注册事件监听器

事件适配器的不足之处：

Java不允许一个类继承两个类，如果一个类已经继承了一个类，就不能再继承适配器类了

import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; public class AdaperListener extends WindowAdapter { //注意这个方法的大小写！否则不会被调用 public void windowClosing(WindowEvent e){ System.out.println("aba"); e.getWindow().dispose(); //释放屏幕资源 System.exit(0); } } f.addWindowListener(new AdaperListener());

4. Button监听

import java.awt.Button; import java.awt.Frame; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; public class ButtonAdapter implements ActionListener { Frame f = new Frame("Hello!"); //static ButtonAdapter ba = new ButtonAdapter(); public void init(){ Button btn = new Button("hello"); f.add(btn); btn.addActionListener(this); //监听当前对象 } public void set(){ f.setSize(500,400); f.setVisible(true); } public static void main(String args[]){ ButtonAdapter ba = new ButtonAdapter(); ba.init(); ba.set(); } public void actionPerformed(ActionEvent e) { f.dispose(); } } 把上述程序改写成为类中类程序： import java.awt.Button; import java.awt.Frame; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; public class ButtonAdapter {//implements ActionListener { Frame f = new Frame("Hello!"); //static ButtonAdapter ba = new ButtonAdapter(); public void init(){ Button btn = new Button("hello"); f.add(btn); btn.addActionListener(new actionAdapter()); //监听当前对象 } public void set(){ f.setSize(500,400); f.setVisible(true); } public static void main(String args[]){ ButtonAdapter ba = new ButtonAdapter(); ba.init(); ba.set(); } class actionAdapter implements ActionListener{ public void actionPerformed(ActionEvent e) { f.dispose(); } } } 把上述程序继续改写成为匿名类： btn.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ f.dispose(); } }); 建议：在编程的时候，不要盯着静态的代码，而是联想着对象的变化 5. 修改组件的默认事件处理方式 protected final void enableEvent(long eventsToEnable)方法，启用由传递给次组件的指定事件掩码参数所定义的事件，当将某个事件类型的事件添加到这个组件时候，自动启用该事件类型，只能由Component的子类调用，该子类需要将指定的事件类型传递给processEvent，而不管是否已注册了侦听器 import java.awt.AWTEvent; import java.awt.Button; import java.awt.Frame; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; class MyButton extends Button{ private MyButton friend = null; public MyButton(String title){ super(title); this.enableEvents(AWTEvent.MOUSE_MOTION_EVENT_MASK); } protected void processMouseMotionEvent(MouseEvent e){ this.setVisible(false); friend.setVisible(true); } public void setFriend(MyButton friend){ this.friend = friend; } } public class TestMybutton extends Frame{ public TestMybutton(){ addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); //dispose调用位置在new WindowAdapter()中，这个时候this是 指WindowAdapter的对象，所以要用this的时候，应该这样写： TestMybutton.this.dispose(); } }); } public static void main(String[] args) { System.out.println("Starting TestMybutton!"); TestMybutton mainFrame = new TestMybutton(); mainFrame.setSize(400,400); mainFrame.setTitle("hello"); MyButton btn1 = new MyButton("快来抓我啊！"); MyButton btn2 = new MyButton("快来抓我啊！"); btn1.setFriend(btn2); btn2.setFriend(btn1); mainFrame.add(btn1,"North"); mainFrame.add(btn2,"South"); mainFrame.setVisible(true); btn1.setVisible(false); //这里要注意mainFrame的setVisable方法的调用时间 } }

6. GUI组件上的图形操作

(1).Graphics类与图形绘制

drawLine,drawString(x,y坐标是相对应左下角)

(2).组件重绘处理

移动窗口原来绘制的图形就没有，这叫做窗口重绘

使用pait(Graphics g)来重绘

调用pait方法时候，是repaint方法调用update方法，update方法再 调用pait方法的过程

import java.awt.Color; import java.awt.Font; import java.awt.Frame; import java.awt.Graphics; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.util.Enumeration; import java.util.Vector; class MyLine{ private int orgX; private int orgY; private int endX; private int endY; public MyLine(int orgX,int orgY,int endX,int endY){ this.orgX = orgX; this.orgY = orgY; this.endX = endX; this.endY = endY; } public void drawMe(Graphics g){ g.drawLine(orgX, orgY, endX, endY); } //定义一个集合类 } public class DrawLine extends Frame{ int orgX,orgY; int endX,endY; MyLine line; Vector vLines = new Vector(); public void paint(Graphics g){ Enumeration e = vLines.elements(); while(e.hasMoreElements()){ line = (MyLine) e.nextElement(); line.drawMe(g); } } public DrawLine(){ addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); } } ); this.addMouseListener(new MouseAdapter(){ public void mousePressed(MouseEvent e){ orgX = e.getX(); orgY = e.getY(); } public void mouseReleased(MouseEvent e){ endX = e.getX(); endY = e.getY(); Graphics g = getGraphics(); /*g.setColor(Color.RED); g.drawString(orgX+","+orgY, orgX, orgY); g.drawString(e.getX()+","+e.getY(), e.getX(), e.getY()); g.setFont(new Font(null,Font.ITALIC|Font.BOLD,30)); //字体名称，字体样式，字体磅值 g.drawLine(orgX,orgY,e.getX(),e.getY()); */ VLines.add(new MyLine(orgX,orgY,endX,endY)); repaint(); } } ); } public static void main(String args[]){ DrawLine mainFrame = new DrawLine(); mainFrame.setTitle("hello!"); mainFrame.setSize(400,400); mainFrame.setVisible(true); } }

(3).图形处理

可以通过Graphics.drawImage

(Image img,int x,int y,ImageObserver observer)来显示图像

使用Component.getTollkit.getImage(String path)获得Image 实例对象

import java.awt.Frame; import java.awt.Graphics; import java.awt.Image; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; public class DrawImage extends Frame{ Image img = getToolkit().getImage("C://Users//姜康//Desktop//网页练习//a.jpg"); public void paint(Graphics g){ g.drawImage(img, 200, 200, this); } public DrawImage(){ addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ DrawImage.this.dispose(); } } ); } public static void main(String args[]){ DrawImage mainFrame = new DrawImage(); mainFrame.setVisible(true); Graphics g = mainFrame.getGraphics(); // while(!g.drawImage(img, 0, 0, mainFrame)){ //} //mainFrame.getGraphics().drawImage(img, 0, 0, mainFrame); mainFrame.setTitle("hello!"); mainFrame.setSize(400,400); } }

7. 双缓冲技术

Component.CreatImage方法创建内存Image对象

在Image对象上进行绘制的结果就成了一幅图像

在Image对象上执行与组件表面同样的绘制，Image对象中的图像时组件表面内容的 复制，当组件重画时候，只需要将内存中的Image对象在组件上画出

import java.awt.Color; import java.awt.Dimension; import java.awt.Font; import java.awt.Frame; import java.awt.Graphics; import java.awt.Image; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; @SuppressWarnings("serial") public class DrawLines extends Frame{ private int orgX; private int orgY; private int endX; private int endY; Image oimg = null; Graphics og = null; public void paint(Graphics og){ if(oimg != null){ og.drawImage(oimg, 0, 0, this); } } public DrawLines(){ setTitle("hello"); setSize(1000,1000); setVisible(true); //Dimension代表窗口的大小 Dimension d = this.getSize(); oimg = this.createImage(d.width, d.height); og = oimg.getGraphics(); addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); } }); this.addMouseListener(new MouseAdapter(){ public void mousePressed(MouseEvent e){ orgX = e.getX(); orgY = e.getY(); } }); this.addMouseListener(new MouseAdapter(){ public void mouseReleased(MouseEvent e){ endX = e.getX(); endY = e.getY(); og.setColor(Color.RED); og.setFont(new Font(null,Font.ITALIC|Font.BOLD,30)); og.drawString(orgX+","+orgY, orgX, orgY); og.drawString(endX+","+endY, endX, endY); og.drawLine(orgX,orgY,endX,endY); repaint();//一定要加上repaint方法！ } }); } public static void main(String args[]){ @SuppressWarnings("unused") DrawLines mainframe = new DrawLines(); } }

8. AWT组件

(1). Component类

Java图形用户界面最基本的组成部分是组件，组件式一个可以以图形化的方式显示在屏幕上，并能与用户进行交互的对象（按钮，标签）。

它是所有GUI组件的父类，

(2).Cannas类

代表屏幕上的一块空白矩形区域，程序能够在这个部件表面绘图，也能够捕获操作，产生相应的事件，如果自定义GUI功能的组件时，可以继承Canvas，将简化编程

import java.awt.AWTEvent; import java.awt.Canvas; import java.awt.Color; import java.awt.Graphics; import java.awt.event.MouseEvent; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class SetTimer extends Canvas implements Runnable{ long startTime = 0; long endTime = 0; boolean bStart = true; public SetTimer(){ enableEvents(AWTEvent.MOUSE_EVENT_MASK); } protected void processMouseEvent(MouseEvent e){ System.out.println("dsfa"); if(e.getID() == MouseEvent.MOUSE_PRESSED){ bStart = true; startTime = endTime = System.currentTimeMillis(); repaint(); new Thread(this).start(); } else if(e.getID() == MouseEvent.MOUSE_RELEASED){ endTime = System.currentTimeMillis(); repaint(); bStart = false; } super.processMouseEvent(e); } public void paint(Graphics g){ SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss"); Date dt = null; try { dt = sdf.parse("00:00:00"); } catch (ParseException e1) { e1.printStackTrace(); } dt.setTime(dt.getTime()+endTime-startTime); String strTime = sdf.format(dt); g.fill3DRect(0, 0, 78, 28, true); //默认填充色为黑色，必须在setColor前填充，否则看不出来 g.setColor(Color.WHITE); g.drawString(strTime, 10, 20); } public void run(){ while(bStart){ try{ Thread.sleep(500); }catch(Exception e){ e.printStackTrace(); } endTime = System.currentTimeMillis(); repaint(); } } }

(3). 菜单类

菜单由菜单条，菜单，菜单项组成

MenuBar(菜单条)、Menu(菜单)、MenuItem(菜单项)

import java.awt.event.*; public class MenuListner implements ActionListener{ public void actionPerformed(ActionEvent e){ if(e.getActionCommand().equals("printview")){ System.out.println("doing printview"); } else if(e.getActionCommand().equals("setting")){ System.out.println("doing setting"); } } } import java.awt.*; import java.awt.event.*; public class TestMenuBar extends Frame{ MenuBar menubar = new MenuBar(); Menu fileM = new Menu("File"); Menu editM = new Menu("Edit"); Menu toolsM = new Menu("Tools"); Menu helpM = new Menu("Help"); MenuItem fileMI1 = new MenuItem("New"); MenuItem fileMI2 = new MenuItem("Open"); MenuItem fileMI3 = new MenuItem("Save"); Menu fileM4 = new Menu("print"); MenuItem printMI1 = new MenuItem("printview"); MenuItem printMI2 = new MenuItem("setting"); CheckboxMenuItem fileMI5 = new CheckboxMenuItem("Quit",true); public TestMenuBar(){ menubar.add(fileM); menubar.add(editM); menubar.add(toolsM); menubar.add(helpM); fileM.add(fileMI1); fileM.add(fileMI2); fileM.add(fileMI3); fileM.add(fileM4); fileM4.add(printMI1); fileM4.add(printMI2); fileM.addSeparator(); fileM.add(fileMI5); this.setMenuBar(menubar); addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); } }); MenuListner m1 = new MenuListner(); printMI1.addActionListener(m1); printMI2.addActionListener(m1); } public static void main(String args[]){ TestMenuBar mainFrame = new TestMenuBar(); mainFrame.setSize(400,400); mainFrame.setTitle("menu"); mainFrame.setVisible(true); } }

(4).Container类是所有容器类的父类,Container.add方法用于将组件添加到容 器中

Container也是Component的子类,因此可以作为组件增加到其他容器上

Dialog与FileDialog类是Container类的子类

模态对话框与非模态对话框

Dialog类的两个构造方法

public Dialog(Frame owner,String title)非模态

public Dialog(Frame owner,String tile,boolean modal)可指定

package testmenubar; import java.awt.*; import java.awt.event.*; public class MyDialog extends Dialog { protected static final String TestDialog = null; private TextField tf = new TextField(10); private String strInfo = null; public MyDialog(Frame owner,String title,boolean model){ super(owner,title,model); setBounds(0,0,200,150); Button b1 = new Button("应用"); Button b2 = new Button("确定"); this.add(tf,"North"); this.add(b1,"Center"); this.add(b2,"East"); if(this.isModal() == true){ b1.setEnabled(false); } b1.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ ((TestDialog)getOwner()).tf.getText(); } }); b2.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ if(isModal() == true){ strInfo = new String(tf.getText()); } else{ ((TestDialog)getOwner()).setInfo(tf.getText()); } dispose(); } }); addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); } }); } public String getInfo(){ return strInfo; } public void setInfo(String strInfo){ tf.setText(strInfo); } }package testmenubar; import java.awt.*; import java.awt.event.*; public class TestDialog extends Frame{ TextField tf = new TextField(10); public TestDialog() { Button b1 = new Button("打开模态对话框"); Button b2 = new Button("打开非模态对话框"); add(tf, "North"); add(b1, "Center"); add(b2, "East"); addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ dispose(); } }); b1.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ MyDialog dlg = new MyDialog(TestDialog.this,"modal dialog",true); dlg.setInfo(tf.getText()); dlg.setVisible(true); tf.setText(dlg.getInfo()); } }); b2.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ MyDialog dlg = new MyDialog(TestDialog.this,"modaless dialog",false); dlg.setInfo(tf.getText()); dlg.setVisible(true); tf.setText(dlg.getInfo()); } }); Button b3 = new Button("确定"); } public static void main(String[] args) { TestDialog mainFrame = new TestDialog(); mainFrame.setSize(400, 400); mainFrame.setVisible(true); } public void setInfo(String text) { return; } }