import  java.util.HashMap;
import  java.util.Iterator;
import  java.util.Map;
import  org.eclipse.swt.graphics.Image;
import  org.eclipse.ui.plugin.AbstractUIPlugin;

public   class  CacheImage  {
  private   final  Map < String, Image >  imageMap  =   new  HashMap < String, Image > ();

  private   static  CacheImage INSTANCE;

  private  CacheImage()  {
 }

  //  单例模式，获得CacheImage实例
  public   static  CacheImage getINSTANCE()  {
   if  (INSTANCE  ==   null )
   INSTANCE  =   new  CacheImage();
   return  INSTANCE;
 }

  //  获得图像
  public  Image getImage(String applicationID,String imageName)  {
   if  (imageName  ==   null )
    return   null ;
  Image image  =  (Image) imageMap.get(imageName);
   if  (image  ==   null )  {
   image  = AbstractUIPlugin.imageDescriptorFromPlugin(
     applicationID,imageName).createImage();
   imageMap.put(imageName, image);
  }
   return  image;
 }

  //  释放图像资源
  public   void  dispose()  {
  Iterator iterator  =  imageMap.values().iterator();
   while  (iterator.hasNext())
   ((Image) iterator.next()).dispose();
  imageMap.clear();
 }
}

窗口居中工具类

import  org.eclipse.swt.graphics.Rectangle;
import  org.eclipse.swt.widgets.Display;
import  org.eclipse.swt.widgets.Shell;

public   class  CenterUtil  {
     public   static   void  centerShell(Display display,Shell shell) {
         Rectangle displayBounds  =  display.getPrimaryMonitor().getBounds();
         Rectangle shellBounds  =  shell.getBounds();
          int  x  =  displayBounds.x  +  (displayBounds.width  -  shellBounds.width) >> 1 ;
          int  y  =  displayBounds.y  +  (displayBounds.height  -  shellBounds.height) >> 1 ;
         shell.setLocation(x, y);
     }
 }

WM_SIZE

The WM_SIZE message is sent to a window after its size has changed.

A window receives this message through its WindowProc function.

LRESULT CALLBACK WindowProc(
HWND hwnd,       // handle to window
UINT uMsg,       // WM_SIZE
WPARAMwParam,   // resizing flag
LPARAMlParam    // client area
);

Parameters

wParam

Specifies the type of resizing requested. This parameter can be one of the following values.

Value	Meaning
SIZE_MAXHIDE	Message is sent to all pop-up windows when some other window is maximized.
SIZE_MAXIMIZED	The window has been maximized.
SIZE_MAXSHOW	Message is sent to all pop-up windows when some other window has been restored to its former size.
SIZE_MINIMIZED	The window has been minimized.
SIZE_RESTORED	The window has been resized, but neither the SIZE_MINIMIZED nor SIZE_MAXIMIZED value applies.

lParam

The low-order word of lParam specifies the new width of the client area.

The high-order word of lParam specifies the new height of the client area.

Return Values

If an application processes this message, it should return zero.