formdemo2.java

来自「一本介绍手机游戏开发的书中的源代码」· Java 代码 · 共 78 行

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class formDemo2 extends MIDlet implements CommandListener
{
   Display display;
   Form    form;
   ChoiceGroup cg;
   int     layout;
   Image   image;
   ImageItem item;
   Command okCmd;
   Command exitCmd;

   public formDemo2()
   {     
      display=Display.getDisplay(this);
      try{
          image=Image.createImage("/picture.png");
      }catch(Exception ex){}
      okCmd=new Command("确认", Command.OK, 2);
      exitCmd=new Command("离开", Command.EXIT, 2);
      form=new Form("Form窗口显示图像");
      cg=new ChoiceGroup("选择",Choice.EXCLUSIVE);
      cg.append("图像偏左",null);  
      cg.append("图像偏右",null);   
      cg.append("图像置中",null);   
      cg.append("图像后面增加空白",null);   
      cg.append("图像前面增加空白",null);
      form.append(cg);
      form.addCommand(okCmd);
      form.addCommand(exitCmd);
      form.setCommandListener(this); 
   }

   public void startApp()
   {
      item=new ImageItem("image", image, layout, "picture.png");
      form.append(item);
      display.setCurrent(form);       
   }

   public void pauseApp(){}

   public void destroyApp(boolean unconditional){}

   public void commandAction(Command cmd, Displayable disp)
   {
      if (cmd == okCmd)
      {
        switch(cg.getSelectedIndex())
        {
          case 0:
               layout=ImageItem.LAYOUT_LEFT;
               break;
          case 1:
               layout=ImageItem.LAYOUT_RIGHT;
               break;
          case 2:
               layout=ImageItem.LAYOUT_CENTER;
               break;
          case 3:
               layout=ImageItem.LAYOUT_NEWLINE_BEFORE;
               break;
          case 4:
               layout=ImageItem.LAYOUT_NEWLINE_AFTER;
               break;
        }
        form.delete(1);
        item.setLayout(layout);
        startApp();
      }
       else if (cmd == exitCmd){
         destroyApp(false);
         notifyDestroyed();
      } 
   }
}