构建不规则窗体

深藏阁楼爱情的钟 2022-05-15 06:28 209阅读 0赞

在开发一个新浪微博客Swing户端的过程中希望能展现不规则的窗体界面，原来JDK 6 update 10提供了创建指定形状窗体的特性，简单易用，记于此处。(2010.05.31最后更新)

Java从JDK 6 update 10开 始将内建支持构建指定形状的窗体，类com.sun.awt.AWTUtilities中的方法setWindowShape会根据不同的Shape实现 去构造相应形状的窗体。AWTUtilities类是放在SUN的包中，在使用该方法时应该通过反射去进行调用，如下代码所示，

Class <?>  clazz  =  Class.forName( " com.sun.awt.AWTUtilities " );  
Method method  =  clazz.getMethod( " setWindowShape " , Window. class , Shape. class );

**1. 创建正常窗体**    
先创建一个简单的界面，它使用BorderLayout，在其中安放5个JButton，如下代码所示，

public  class  ShapedFrame  extends  JFrame \{  
  
 private  static  final  long  serialVersionUID  =  \- 2291343874280454383L ;  
  
 private  JButton centerButton  =  new  JButton( " Center " );  
  
 public  ShapedFrame() \{  
 super ( " Shaped Frame " );  
setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);  
initUI();  
\}  
  
 private  void  initUI() \{  
Container container  =  getContentPane();  
container.setLayout( new  BorderLayout());  
  
container.add( new  JButton( " TOP " ), BorderLayout.PAGE\_START);  
container.add( new  JButton( " RIGHT " ), BorderLayout.LINE\_END);  
container.add( new  JButton( " BOTTOM " ), BorderLayout.PAGE\_END);  
container.add( new  JButton( " LEFT " ), BorderLayout.LINE\_START);  
container.add(centerButton, BorderLayout.CENTER);  
\}  
  
 public  static  void  main(String\[\] args) \{  
SwingUtilities.invokeLater( new  Runnable() \{  
  
@Override  
 public  void  run() \{  
ShapedFrame frame  =  new  ShapedFrame();  
frame.setSize( new  Dimension( 400 ,  300 ));  
frame.setUndecorated( true );  
setAtCenter(frame);  
frame.setVisible( true );  
\}  
\});  
\}  
  
 //  将Window置于屏幕正中   
  private  static  void  setAtCenter(Window window) \{  
Dimension screenSize  =  Toolkit.getDefaultToolkit().getScreenSize();  
window.setLocation((screenSize.width  \-  window.getWidth())  /  2 ,  
(screenSize.height  \-  window.getHeight())  /  2 );  
\}  
\}

执行上述程序的效果如下图所示，  
![01.PNG][]  
  
 **2. 创建不规则窗体**    
基于上述程序创建不规则窗体，使整个窗体正好缺失掉RIGHT JButton所在的区域，如下代码所示，

public  class  ShapedFrame  extends  JFrame \{  
  
 private  static  final  long  serialVersionUID  =  \- 2291343874280454383L ;  
  
 private  static  Method method  =  null ;  
  
 static  \{  
 try  \{  
Class <?>  clazz  =  Class.forName( " com.sun.awt.AWTUtilities " );  
method  =  clazz.getMethod( " setWindowShape " , Window. class , Shape. class );  
\}  catch  (Exception e) \{  
e.printStackTrace();  
\}  
\}  
  
 private  JButton centerButton  =  new  JButton( " Center " );  
  
 public  ShapedFrame() \{  
 super ( " Shaped Frame " );  
setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);  
initUI();  
addComponentListener(componentListener);  
\}  
  
 private  void  initUI() \{  
Container container  =  getContentPane();  
container.setLayout( new  BorderLayout());  
  
container.add( new  JButton( " TOP " ), BorderLayout.PAGE\_START);  
container.add( new  JButton( " RIGHT " ), BorderLayout.LINE\_END);  
container.add( new  JButton( " BOTTOM " ), BorderLayout.PAGE\_END);  
container.add( new  JButton( " LEFT " ), BorderLayout.LINE\_START);  
container.add(centerButton, BorderLayout.CENTER);  
\}  
  
 private  ComponentListener componentListener  =  new  ComponentAdapter() \{  
  
@Override  
 public  void  componentResized(ComponentEvent evt) \{ // 当UI组件(JFrame)的尺寸发生改变时，调用该方法  
Rectangle frameRect  =  getBounds();  
Rectangle spaceRect  =  centerButton.getBounds();  
  
Point o1  =  new  Point( 0 ,  0 );  
Point o2  =  new  Point(frameRect.width,  0 );  
Point o3  =  new  Point(frameRect.width, frameRect.height);  
Point o4  =  new  Point( 0 , frameRect.height);  
  
Point i1  =  new  Point(spaceRect.x  \+  spaceRect.width, spaceRect.y);  
Point i2  =  new  Point(frameRect.width, spaceRect.y);  
Point i3  =  new  Point(frameRect.width, spaceRect.y  
 \+  spaceRect.height);  
Point i4  =  new  Point(spaceRect.x  \+  spaceRect.width, spaceRect.y  \+  spaceRect.height);  
  
 int \[\] xpoints  =  new  int \[\] \{ o1.x, o2.x, i2.x, i1.x, i4.x, i3.x, o3.x, o4.x \};  
 int \[\] ypoints  =  new  int \[\] \{ o1.y, o2.y, i2.y, i1.y, i4.y, i3.y, o3.y, o4.y \};  
 int  npoints  =  8   
// 构建一个六边形，将RIGHT JButton所处的位置空缺出来   
Shape shape  =  new  Polygon(xpoints, ypoints, npoints);  
  
setWindowShape(ShapedFrame. this , shape);  
\}  
\};  
  
 //  设置Window的形状   
  private  static  void  setWindowShape(Window window, Shape shape) \{  
 try  \{  
method.invoke( null , window, shape);  
\}  catch  (Exception e) \{  
e.printStackTrace();  
\}  
\}  
  
 public  static  void  main(String\[\] args) \{  
SwingUtilities.invokeLater( new  Runnable() \{  
  
@Override  
 public  void  run() \{  
ShapedFrame frame  =  new  ShapedFrame();  
frame.setSize( new  Dimension( 400 ,  300 ));  
frame.setUndecorated( true );  
setAtCenter(frame);  
frame.setVisible( true );  
\}  
\});  
\}  
  
 //  将Window置于屏幕正中   
  private  static  void  setAtCenter(Window window) \{  
Dimension screenSize  =  Toolkit.getDefaultToolkit().getScreenSize();  
window.setLocation((screenSize.width  \-  window.getWidth())  /  2 ,  
(screenSize.height  \-  window.getHeight())  /  2 );  
\}  
\}

执行上述程序后，会有如下图所示的效果，  
![02.PNG][]

[01.PNG]: /images/20220515/66d2b4f5c2024fba97d0f81d9b45e4ae.png
[02.PNG]: /images/20220515/d6c798a1e47a450d938c1cead35ed789.png