例9-9.java

医院无线局域网设计方案 医院无线局域网设计方案

//Example 9.9
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
public class SeePic extends Frame implements ActionListener,WindowListener
{	
  private Image myImage;
  private boolean haveImage=false;
  public SeePic()
  {
    super("See Picture");
    Menu mn=new Menu("File");
    MenuItem miOpen=new MenuItem("Open");
    MenuItem miExit=new MenuItem("Exit");
    mn.add(miOpen);
    mn.addSeparator();
    mn.add(miExit);
    miOpen.addActionListener(this);
    miExit.addActionListener(this);
    MenuBar mb=new MenuBar();
    mb.add(mn);
    setMenuBar(mb);
    addWindowListener(this);
    setSize(800,600);
    setVisible(true);
  }
  public static void main(String args[]) throws IOException
  {
    new SeePic();
  }
  public void windowClosing(WindowEvent e){System.exit(0);}
  public void windowActivated(WindowEvent e){ } 
  public void windowClosed(WindowEvent e){ }
  public void windowDeactivated(WindowEvent e){ }
  public void windowDeiconified(WindowEvent e){ }
  public void windowIconified(WindowEvent e){ }
  public void windowOpened(WindowEvent e){ }
  public void actionPerformed(ActionEvent e)
  { 
    String strCmd=e.getActionCommand();
    if(strCmd.equals("Exit")) System.exit(0);
    else openPic();
  }
  public void openPic()
  {
    String picdir="",picfilename="",picname="";
    try
    {
      FileDialog fd=new FileDialog(this,"Picture File");
      fd.setVisible(true);
      picdir=fd.getDirectory();
      picfilename=fd.getFile();
      picname=picdir+picfilename;
      //System.out.println("File name:"+picname);
      if(picfilename.endsWith("jpg")||picfilename.endsWith("gif"))
        showPic(picname);
      else
      {
        haveImage=false;repaint();
      }
    }
    catch(Exception e){System.out.println("Cancled");
    }
  }
  public void showPic(String picname)
  {
    Toolkit tlkt=getToolkit();
    myImage=tlkt.getImage(picname);
    haveImage=true;
    repaint();
  }
  public void paint(Graphics g)
  {
    if(haveImage)
    {
      Image imageBuffer=createImage(getSize().width,getSize().height);
      Graphics gBuffer=imageBuffer.getGraphics();
      gBuffer.drawImage(myImage,0,40,this);
      gBuffer.dispose();
      g.drawImage(imageBuffer,0,0,this);
    }
  }
  public boolean imageUpdate(Image img,int infoflag,int x,int y,int width,int height)
  {
    if((infoflag&ImageObserver.ALLBITS)!=0)
    {
      repaint();return false;
    }
    return true;
  }
}