知识点：
- JFrame窗体类关键属性、方法和事件的应用
- Canvas画板类的关键方法和事件的应用
- 窗体菜单栏的创建和层级关系
- 工具栏、按钮的配合使用
- 鼠标点击、移动事件的使用
- AWT绘图方法的使用
Swing组件：
- JFrame窗体类
- JWindow无边框窗体类
- JButton窗体类
- JToggleButton按钮类
- JMenuBar菜单栏类
- JMenu菜单类
- JMenuItem菜单项类
Swing事件监听：
- 鼠标点击
- 鼠标拖曳
Java技术：
- Graphics2D绘图类
- Java继承
- 主类、主方法概念
- File文件类
- Image图片类
- Ellipse2D圆形图形类
- Rectangle2D方形图形类
1.创建项目和导入资源
在Package Explorer的Other Projects，右键-New-Other-Java Project-next-(输入项目名:一起来画画)Finish;
在项目名上，右键-New-Folder-(选择文件夹：一起来画画,在Folder name输入:lib)Finish;
将外部包DrawUtil.mr.jar复制到lib里，然后在项目名上，右键-Build Path-Configure Build Path-Libraries-Add JARs...-选中"一起来画画/lib/DrawUtil.mr.jar"-OK;
2.编码
1 package com.mr.draw;
2
3 import javax.swing.JFrame;
4
5 import java.awt.Color;
6 import java.awt.Graphics;
7 import java.awt.Graphics2D;
8 import java.awt.image.BufferedImage;
9
10 import java.awt.event.MouseAdapter;
11 import java.awt.event.MouseEvent;
12 import java.awt.event.MouseMotionAdapter;
13
14 import java.awt.BorderLayout;
15 import javax.swing.ButtonGroup;
16 import javax.swing.JButton;//按钮类
17 import javax.swing.JToggleButton;///画线类
18 import javax.swing.JToolBar;//工具栏类
19
20 import java.awt.BasicStroke;
21 import java.awt.event.ActionEvent;
22 import java.awt.event.ActionListener;//调整画笔粗细
23
24 import javax.swing.JColorChooser;//实现添加颜色功能
25
26 import java.awt.geom.Ellipse2D;
27 import java.awt.geom.Rectangle2D;
28 import com.mr.util.FrameGetShape;
29 import com.mr.util.ShapeWindow;
30 import com.mr.util.Shapes; ///实现绘制图形功能
31
32 import com.mr.util.DrawImageUtil;//实现图片保存功能
33
34 import javax.swing.JMenu;
35 import javax.swing.JMenuBar;
36 import javax.swing.JMenuItem;//实现 添加菜单栏
37
38 import java.awt.AlphaComposite;
39 import java.awt.Font;
40 import javax.swing.JOptionPane;//实现添加水印，为自己作品署名
41
42 import java.awt.Image;
43 import java.awt.Point;
44 import java.awt.Toolkit;//工具箱
45 import java.awt.Cursor;//光标，实现更改鼠标图标功能
46 import javax.swing.ImageIcon;
47
48 //画图主窗体
49 public class DrawPictureFrame extends JFrame implements FrameGetShape{//继承窗体类,实现绘制图形的接口
50 //创建一个8位BGR颜色分量的图像
51 BufferedImage image = new BufferedImage(570,390,BufferedImage.TYPE_3BYTE_BGR);
52 Graphics gs = image.getGraphics();
53 Graphics2D g = (Graphics2D)gs;
54 DrawPictureCanvas canvas = new DrawPictureCanvas(); //创建画布对象
55 Color foreColor = Color.red; //前景色
56 Color backgroundColor = Color.green; //背景色
57
58 int x=-1;
59 int y=-1;//上一次鼠标绘制点的横纵坐标
60 boolean rubber=false;//橡皮识别变量
61
62 private JToolBar toolBar;//工具栏目
63 private JButton eraserButton;
64 private JToggleButton strokeButton1;
65 private JToggleButton strokeButton2;
66 private JToggleButton strokeButton3;//细中粗按钮
67 private JButton backgroundButton;
68 private JButton foregroundButton;
69 private JButton clearButton;
70 private JButton saveButton;
71 private JButton shapeButton;//图形按钮
72 boolean drawShape = false;
73 Shapes shape;
74 private JMenuItem strokeMenuItem1;
75 private JMenuItem strokeMenuItem2;
76 private JMenuItem strokeMenuItem3;
77 private JMenuItem clearMenuItem;
78 private JMenuItem foregroundMenuItem;
79 private JMenuItem backgroundMenuItem;
80 private JMenuItem eraserMenuItem;
81 private JMenuItem exitMenuItem;//退出菜单
82 private JMenuItem saveMenuItem;
83 private JMenuItem shuiyinMenuItem;//水印菜单
84 private String shuiyin = "";//水印字符内容
85 private PictureWindow picWindow;//简笔画展示窗体
86 private JButton showPicButton;//展开简笔画按钮
87
88
89 public DrawPictureFrame()
90 {
91 setResizable(false); // 窗体大小不能改变
92 //setTitle("画图程序");
93 setTitle("画图程序(水印内容:[" + shuiyin + "] )" );
94 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 窗体关闭则立即停止程序
95 setBounds(500, 100, 574, 460); // 设置窗口的位置和宽高
96
97 init();//组件初始化
98 addListener();//添加组件监听
99 }
100
101 private void init()
102 {
103 g.setColor(backgroundColor);//用前景色设置绘图对象的颜色
104 g.fillRect(0, 0, 570, 390);//用背景色填充整个画布,第一个0和570表示位置从0开始到57
105 g.setColor(foreColor);//用前景色设置绘图对象的颜色
106 canvas.setImage(image);//设置画布的图像
107 getContentPane().add(canvas);//将画布添加到窗体容器默认布局中的中部位置
108
109 toolBar = new JToolBar();//初始化工具栏
110 toolBar.setFloatable(false);//工具栏固定
111 getContentPane().add(toolBar,BorderLayout.NORTH);//将工具栏添加到窗体最北位置
112
113 //showPicButton = new JButton("展开简笔画");
114 showPicButton = new JButton();
115 showPicButton.setToolTipText("展开简笔画");
116 showPicButton.setIcon( new ImageIcon("src/img/icon/展开.png") );//需要导入ImageIcon
117 toolBar.add(showPicButton);
118
119 saveButton = new JButton("保存");
120 toolBar.add(saveButton);
121 toolBar.addSeparator();//添加工具栏
122 strokeButton1 = new JToggleButton("细线");
123 strokeButton1.setSelected(true);//细线按钮处于被选中状态
124 toolBar.add(strokeButton1);
125
126 strokeButton2 = new JToggleButton("粗线");
127 toolBar.add(strokeButton2);
128
129 strokeButton3 = new JToggleButton("较粗");
130 toolBar.add(strokeButton3);
131 toolBar.addSeparator();
132 ButtonGroup strokeGroup = new ButtonGroup();//画笔粗细按钮组，保证同时只有一个被选中
133 strokeGroup.add(strokeButton1);
134 strokeGroup.add(strokeButton2);
135 strokeGroup.add(strokeButton3);
136
137 backgroundButton = new JButton("背景颜色");
138 toolBar.add(backgroundButton);
139 foregroundButton = new JButton("前景颜色");
140 toolBar.add(foregroundButton);
141 toolBar.addSeparator();
142
143 shapeButton = new JButton("图形");
144 toolBar.add(shapeButton);
145 clearButton = new JButton("清除");
146 toolBar.add(clearButton);
147 eraserButton = new JButton("橡皮");
148 toolBar.add(eraserButton);
149 toolBar.addSeparator();
150
151 JMenuBar menuBar = new JMenuBar();
152 setJMenuBar(menuBar);
153
154 JMenu systemMenu = new JMenu("系统");
155 menuBar.add(systemMenu);
156 shuiyinMenuItem = new JMenuItem("设置水印");
157 systemMenu.add(shuiyinMenuItem);
158 saveMenuItem = new JMenuItem("保存");
159 systemMenu.add(saveMenuItem);
160 systemMenu.addSeparator();
161 exitMenuItem = new JMenuItem("退出");
162 systemMenu.add(exitMenuItem);
163 JMenu strokeMenu = new JMenu("线型");
164 menuBar.add(strokeMenu);
165 strokeMenuItem1 = new JMenuItem("细线");
166 strokeMenu.add(strokeMenuItem1);
167 strokeMenuItem2 = new JMenuItem("粗线");
168 strokeMenu.add(strokeMenuItem2);
169 strokeMenuItem3 = new JMenuItem("较线");
170 strokeMenu.add(strokeMenuItem3);
171
172 JMenu colorMenu = new JMenu("颜色");
173 menuBar.add(colorMenu);
174 foregroundMenuItem = new JMenuItem("前景颜色");
175 colorMenu.add(foregroundMenuItem);
176 backgroundMenuItem = new JMenuItem("背景颜色");
177 colorMenu.add(backgroundMenuItem);
178
179 JMenu editMenu = new JMenu("编辑");
180 menuBar.add(editMenu);
181 clearMenuItem = new JMenuItem("清除");
182 editMenu.add(clearMenuItem);
183 eraserMenuItem = new JMenuItem("橡皮");
184 editMenu.add(eraserMenuItem);
185
186 picWindow = new PictureWindow(DrawPictureFrame.this);
187 }
188
189 //动作监听
190 private void addListener()
191 {
192 canvas.addMouseMotionListener(new MouseMotionAdapter(){
193
194 public void mouseDragged( final MouseEvent e )//鼠标拖曳监听
195 {
196 if(x>0 && y>0)//如果x和y存在鼠标记录
197 {
198 if(rubber)//如果是橡皮则画出背景色，相当于擦掉前景色
199 {
200 g.setColor(backgroundColor);
201 g.fillRect(x, y, 10, 10);
202 }
203 else //否则画出
204 g.drawLine(x,y,e.getX(),e.getY());
205 }
206 x=e.getX();
207 y=e.getY();//上一次鼠标绘制点的横纵坐标
208 canvas.repaint();//更新画布
209 }
210 public void mouseMoved(final MouseEvent arg0) {
211 if(rubber)//如果使用橡皮
212 {
213 Toolkit kit = Toolkit.getDefaultToolkit();//获得系统默认的组件工具包
214 Image img = kit.createImage("src/img/icon/鼠标橡皮.png");//利用工具包获取图片
215 Cursor c = kit.createCustomCursor(img,new Point(0,0),"clear");//参数为图片，光标热点和光标描述的字符串
216 setCursor(c);//使用自定义光标
217 }
218 else
219 setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));//不是橡皮则是画笔，则设置光标为十字形
220 }
221 });
222 canvas.addMouseListener(new MouseAdapter() {//鼠标点击监听
223 public void mouseReleased( final MouseEvent arg0 )//按键抬起时
224 {
225 x=-1;
226 y=-1;//将上一次鼠标绘制点的横纵坐标恢复成-1
227 //改成x=11,y=11？？？
228 }
229
230 public void mousePressed(MouseEvent e)//当按键按下时
231 {
232 if( drawShape )//如果此时鼠标画的是
233 {
234 switch( shape.getType() )//判断图形种类
235 {
236 case Shapes.YUAN:
237 int yuanX = e.getX()-shape.getWidth()/2;
238 int yuanY = e.getY()-shape.getHeigth()/2;
239 /*
240 System.out.println(e.getX()+" "+e.getY());
241 System.out.println(shape.getWidth()/2+" "+shape.getHeigth()/2);
242 System.out.println(yuanX+" "+yuanY);*/
243 //创建圆形图形，根据长宽可能是椭圆，指定坐标和宽高
244 Ellipse2D yuan = new Ellipse2D.Double(yuanX,yuanY,shape.getWidth(),shape.getHeigth());
245 g.draw(yuan);
246 break;
247 case Shapes.FANG:
248 int fangX=e.getX()-shape.getWidth()/2;
249 int fangY=e.getY()-shape.getHeigth()/2;
250 Rectangle2D fang = new Rectangle2D.Double(fangX,fangY,shape.getWidth(),shape.getHeigth());
251 g.draw(fang);
252 break;
253 }
254 canvas.repaint();
255 drawShape = false;//画一个就不能画了
256 }
257 }
258 });
259
260 toolBar.addMouseMotionListener(new MouseMotionAdapter() {//工具栏添加鼠标移动监听
261 public void mouseMoved(final MouseEvent arg0) {//鼠标移动时，设置鼠标指针的形状为默认光标
262 setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
263 }
264 });
265
266 //调整画笔粗细
267 strokeButton1.addActionListener(new ActionListener() {//细线按钮添加监听
268 public void actionPerformed(final ActionEvent arg0)//单击时
269 { //声明画笔的属性，粗细为1像素，线条末端无修饰，折线处呈尖角
270 BasicStroke bs = new BasicStroke(1, BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
271 g.setStroke(bs);//画图工具使用此笔
272 }
273 });
274 strokeButton2.addActionListener(new ActionListener() {//中线按钮添加监听
275 public void actionPerformed(final ActionEvent arg0)//单击时
276 { //声明画笔的属性，中线为2像素，线条末端无修饰，折线处呈尖角
277 BasicStroke bs = new BasicStroke(2,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
278 g.setStroke(bs);//画图工具使用此笔
279 }
280
281 });
282 strokeButton3.addActionListener(new ActionListener() {//粗线按钮添加监听
283 public void actionPerformed(final ActionEvent arg0)//单击时
284 { //声明画笔的属性，粗线为4像素，线条末端无修饰，折线处呈尖角
285 BasicStroke bs = new BasicStroke(4,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
286 g.setStroke(bs);//画图工具使用此笔
287 }
288 });
289
290 //实现颜色添加功能
291 backgroundButton.addActionListener( new ActionListener() {
292 public void actionPerformed( final ActionEvent arg0 )
293 { //打开选择颜色对话框，参数依次是：符窗体、标题、默认选中的颜色（青色）
294 Color bgColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
295 if ( bgColor !=null )///选中的颜色不是空的
296 backgroundColor = bgColor;//则将选中的颜色赋给背景色
297 backgroundButton.setBackground(backgroundColor);
298 g.setColor(backgroundColor);
299 g.fillRect(0, 0, 570, 390);//画一个背景颜色的方形填满整个画布
300 g.setColor(foreColor);
301 canvas.repaint();//更新画布
302 }
303 });
304 foregroundButton.addActionListener(new ActionListener() {
305 public void actionPerformed(final ActionEvent arg0)
306 {
307 Color fColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
308 if(fColor != null)
309 foreColor = fColor;
310 foregroundButton.setForeground(foreColor);
311 g.setColor(foreColor);
312 }
313
314 });
315
316 //清除按钮和橡皮按钮
317 clearButton.addActionListener(new ActionListener() {
318 public void actionPerformed( final ActionEvent arg0 ) {
319 g.setColor(backgroundColor);
320 g.fillRect(0, 0, 570, 390);//用背景色填充以达到清除效果，然后画笔换成前景色，继续作画
321 g.setColor(foreColor);
322 canvas.repaint();//更新画布
323 }
324 });
325 eraserButton.addActionListener(new ActionListener() {
326 public void actionPerformed(final ActionEvent arg0)
327 {
328 if( eraserButton.getText().equals("橡皮") )
329 {
330 rubber = true;
331 eraserButton.setText("画图");
332 }
333 else
334 {
335 rubber = false;
336 eraserButton.setText("橡皮");
337 g.setColor(foreColor);
338
339 }
340 }
341 });
342
343
344 //图形绘制按钮
345 shapeButton.addActionListener(new ActionListener() {
346 public void actionPerformed(ActionEvent e)//单击时
347 {
348 //创建图形选择组件
349 ShapeWindow shapeWindow = new ShapeWindow(DrawPictureFrame.this);
350 int shapeButtonWidth = shapeButton.getWidth();
351 int shapeWindowWidth = shapeWindow.getWidth();
352 int shapeButtonX = shapeButton.getX();
353 int shapeButtonY = shapeButton.getY();
354 int shapeWindowX = getX() - shapeButtonX - ( shapeWindowWidth-shapeButtonWidth )/2;
355 int shapeWindowY = getY() - shapeButtonY + 80;
356 shapeWindow.setLocation(shapeWindowX,shapeWindowY);
357 shapeWindow.setVisible(true);//图形组件可见，如果是false点击图形啥都没有
358 }
359
360 });
361
362 //保存按钮实现保存功能
363 saveButton.addActionListener(new ActionListener() {
364 public void actionPerformed(final ActionEvent arg0) {//单击时
365 addWatermark();//添加水印
366 DrawImageUtil.saveImage(DrawPictureFrame.this,image );//打印图片
367 }
368
369 });
370
371 exitMenuItem.addActionListener(new ActionListener() {///退出菜单动作监听
372 public void actionPerformed(final ActionEvent e)///单击时程序退出
373 {
374 System.exit(0);
375 }
376 });
377
378 eraserMenuItem.addActionListener(new ActionListener() {
379 public void actionPerformed(final ActionEvent e) {
380 if( eraserMenuItem.getText().contentEquals("橡皮") ) {
381 rubber = true;
382 eraserMenuItem.setText("画图");
383 eraserButton.setText("画图");
384 }
385 else
386 {
387 rubber = false;
388 eraserMenuItem.setText("橡皮");
389 eraserButton.setText("橡皮");
390 g.setColor(foreColor);
391 }
392 }
393 });
394
395 clearMenuItem.addActionListener(new ActionListener() {
396 public void actionPerformed(final ActionEvent e) {
397 g.setColor(backgroundColor);
398 g.fillRect(0, 0, 570, 390);
399 g.setColor(foreColor);
400 canvas.repaint();
401
402 }
403 });
404
405 strokeMenuItem1.addActionListener(new ActionListener() {//细线菜单添加动作监听
406 public void actionPerformed(final ActionEvent e) {
407 //像素为1，线条末端无修饰，折线处呈尖角
408 BasicStroke bs = new BasicStroke(1,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
409 g.setStroke(bs);//画图工具使用此笔
410 strokeButton1.setSelected(true);//细线按钮设为选中状态
411 }
412 });
413
414 strokeMenuItem2.addActionListener(new ActionListener() {
415 public void actionPerformed(final ActionEvent e) {
416 BasicStroke bs = new BasicStroke(2,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
417 g.setStroke(bs);
418 strokeButton2.setSelected(true);
419 }
420 });
421
422 strokeMenuItem3.addActionListener(new ActionListener() {
423 public void actionPerformed(final ActionEvent e) {
424 BasicStroke bs = new BasicStroke(4,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER);
425 g.setStroke(bs);
426 strokeButton3.setSelected(true);
427 }
428 });
429
430 foregroundMenuItem.addActionListener(new ActionListener() {
431 public void actionPerformed(final ActionEvent e) {
432 Color fColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
433 if( fColor != null )
434 foreColor = fColor;
435 foregroundButton.setForeground(foreColor);
436 g.setColor(foreColor);
437 }
438 });
439
440 backgroundMenuItem.addActionListener(new ActionListener() {
441 public void actionPerformed(final ActionEvent e) {
442 Color bgColor = JColorChooser.showDialog(DrawPictureFrame.this, "选择颜色对话框", Color.CYAN);
443 if( bgColor != null )
444 backgroundColor = bgColor;
445 backgroundButton.setBackground(backgroundColor);
446 g.setColor(backgroundColor);
447 g.fillRect(0, 0, 570, 390);
448 g.setColor(foreColor);
449 canvas.repaint();
450 }
451 });
452
453 saveMenuItem.addActionListener(new ActionListener() {
454 public void actionPerformed(ActionEvent e) {
455 addWatermark();//添加水印
456 DrawImageUtil.saveImage(DrawPictureFrame.this,image);//打印图片
457 }
458 });
459
460 shuiyinMenuItem.addActionListener(new ActionListener() {
461 public void actionPerformed(ActionEvent e) {
462 //输入对话框
463 System.out.println("facai1");
464 shuiyin = JOptionPane.showInputDialog(DrawPictureFrame.this,"你想添加什么水印？");
465 System.out.println("facai2");
466 if ( null == shuiyin)
467 shuiyin="";
468 else
469 setTitle("画图程序(水印内容：[ " + shuiyin + " ])");//修改窗体标题
470 System.out.println("facai3");
471 }
472 });
473
474 showPicButton.addActionListener(new ActionListener() {
475 public void actionPerformed(ActionEvent e) {
476 boolean isVisible = picWindow.isVisible();
477 if(isVisible) {
478 showPicButton.setText("展开简笔画");
479 picWindow.setVisible(false);
480 }
481 else
482 {
483 showPicButton.setText("隐藏简笔画");
484 //重新指定简笔画展示窗体的显示位置
485 //横坐标 = 主窗体横坐标 - 简笔画窗体宽度 - 5； 纵坐标 = 主窗体纵坐标
486 picWindow.setLocation(getX()-picWindow.getWidth()-5,getY());
487 picWindow.setVisible(true);
488 }
489 }
490 });
491
492
493
494 }
495
496 //添加水印
497 private void addWatermark() {
498 if( !"".equals(shuiyin.trim()) )///shuiyin变量删除头尾空白字符后 不等于空
499 {
500 g.rotate(Math.toRadians(-30));//将图片旋转-30弧度
501 Font font = new Font("楷体",Font.BOLD,72);//设置字体
502 g.setFont(font);
503 g.setColor(Color.GRAY);
504 AlphaComposite alpha = AlphaComposite.SrcOver.derive(0.4f);//设置透明效果
505 g.setComposite(alpha);
506 g.drawString(shuiyin, 75, 400);//绘制文字
507 canvas.repaint();
508 g.rotate(Math.toRadians(30));//将旋转的图片再旋转回来
509 alpha = AlphaComposite.SrcOver.derive(1f);//不透明效果
510 g.setComposite(alpha);//使用不透明效果
511 g.setColor(foreColor);//画笔恢复之前颜色
512 }
513 }
514
515 //恢复展开简笔画按钮的文本内容，此方法供简笔画面板的"隐藏"按钮调用
516 public void initShowPicButton() {
517 showPicButton.setText("展开简笔画");
518 }
519
520
521 //FrameGetShape接口实现类，用于获得图形空间返回的被选中的图形
522 public void getShape(Shapes shape)
523 {
524 this.shape=shape;//将返回的图形对象赋给类的全局变量
525 drawShape = true;//画图形标识变量为true，说明现在鼠标画的是图形，而不是线条
526 }
527
528
529
530
531
532 public static void main(String[] args)
533 {
534 DrawPictureFrame frame = new DrawPictureFrame();//创建窗体对象
535 frame.setVisible(true);//让窗体可见
536 }
537
538 }
1 package com.mr.draw;
2
3 import java.awt.Canvas;
4 import java.awt.Graphics;
5 import java.awt.Image;
6
7
8 public class DrawPictureCanvas extends Canvas{
9 private Image image = null;//创建画板中展示的图片对象
10 //设置画板中的图片
11 public void setImage( Image image)
12 {
13 this.image = image;
14 }
15 //重写，在画布上绘制图像
16 public void paint( Graphics g )
17 {
18 g.drawImage( image,0,0,null );
19 }
20
21 //重写，解决屏幕闪烁问题
22 public void update( Graphics g )
23 {
24 paint(g);
25 }
26 }
1 package com.mr.draw;
2
3 import java.awt.BorderLayout;
4 import java.awt.Container;
5 import java.awt.FlowLayout;
6 import java.awt.Image;
7 import java.awt.event.ActionEvent;
8 import java.awt.event.ActionListener;
9 import java.io.File;
10 import javax.swing.ImageIcon;
11 import javax.swing.JButton;
12 import javax.swing.JPanel;//面板
13 import javax.swing.JWindow;
14 import com.mr.util.BackgroundPanel;
15
16
17
18 public class PictureWindow extends JWindow {
19 private JButton changeButton;
20 private JButton hiddenButton;
21 private BackgroundPanel centerPanel;
22 File list[];
23 int index;
24 DrawPictureFrame frame;
25
26 //构造方法
27 public PictureWindow(DrawPictureFrame frame) {
28 this.frame = frame;//构造参数的值赋给父窗体
29 setSize(400,460);
30 init();
31 addListener();
32 }
33
34 private void init() {
35 Container c = getContentPane();
36 File dir = new File("src/img/picture");
37 list = dir.listFiles();
38 centerPanel = new BackgroundPanel(getListImage());
39 c.add(centerPanel,BorderLayout.CENTER);//背景面板放到主容器的中部
40 FlowLayout flow = new FlowLayout(FlowLayout.RIGHT);//右对齐流布局
41 flow.setHgap(20);//水平间隔20像素
42 JPanel southPanel = new JPanel();//创建南部面板
43 southPanel.setLayout(flow);//使用刚才建好的流布局
44 changeButton = new JButton("更换图片");
45 southPanel.add(changeButton);
46 hiddenButton = new JButton("隐藏");
47 southPanel.add(hiddenButton);
48 c.add(southPanel,BorderLayout.SOUTH);//南部面板放在主容器的南部
49 }
50
51 //添加监听
52 private void addListener() {
53 hiddenButton.addActionListener(new ActionListener() {
54 public void actionPerformed(ActionEvent e) {
55 setVisible(false);//隐藏按钮点击时窗体不可见
56 frame.initShowPicButton();
57 }
58 });
59 changeButton.addActionListener(new ActionListener() {
60 public void actionPerformed(ActionEvent e) {
61 centerPanel.setImage(getListImage());//更换图片按钮点击时背景面板重新载入图片
62 }
63 });
64 }
65
66 private Image getListImage() {
67 String imgPath = list[index].getAbsolutePath();
68 ImageIcon image = new ImageIcon(imgPath);
69 index++;
70 if(index>=list.length)
71 index=0;
72 return image.getImage();
73 }
74
75 }
3.项目界面
