6.2.1 基本界面信息

/×
  控制手机界面颜色的程序
×/
import javax.microedition.midlet.×;
import javax.microedition.lcdui.×;
public class colorControl extends MIDlet
{
   Display display;
   canvasColor canvascolor;
   public colorControl()
   {
      canvascolor=new canvasColor();
      display=Display.getDisplay(this);
   }
   public void startApp()
   {
      display.setCurrent(canvascolor);
   }
   public void pauseApp(){}
   public void destroyApp(boolean unconditional){}
   class canvasColor extends Canvas 
   {
      int     gameaction=0;
      //设置传入画面的红色数值
      int     red=150;
      //设置传入画面的绿色数值
      int     green=150;
      //设置传入画面的蓝色数值
      int     blue=150;
      int     colorType=0;
      Image   handImage;
      public canvasColor()
      {
         try{
             handImage=Image.createImage("/hand.png");
         }catch(Exception ex){}
      }
      
      public void keyPressed(int keyCode) 
      {
         gameaction=getGameAction(keyCode);
         switch(gameaction)
         {
            case UP:
                //通过选择来控制界面的颜色值，从0到255之间
                if(colorType==0)
                {
                   red++;
                   if(red>255) red=255;
                } 
                 else if(colorType==1){
                   green++;
                   if(green>255) green=255;
                }
                 else{
                   blue++;
                   if(blue>255) blue=255;
                }
                repaint();
                break;
            case DOWN:
                if(colorType==0)
                {
                  red--;
                  if(red<0) red=0;
                } 
                 else if(colorType==1){
                   green--;
                   if(green<0) green=0;
                }
                 else{
                   blue--;
                   if(blue<0) blue=0;
                }
                repaint();
                break;
//控制颜色种类的变更
            case LEFT:
                colorType--;
                if(colorType<0) colorType=0;
                repaint();
                break;
            case RIGHT:
                colorType++;
                if(colorType>2) colorType=2;
                repaint();                 
                break;
          }
      }
      public void paint(Graphics g)
      {
         //设置当前手机背景画面颜色
         g.setColor(red, green, blue);
         //用设置的颜色填充屏幕背景
         g.fillRect(0,0,getWidth(),getHeight());
         //设置文字的颜色
         g.setColor(0);
         g.drawString("游戏界面数值表", getWidth()/2, 20, Graphics.HCENTER | 
Graphics.TOP);
         g.drawString("请按上、下键选择颜色数值", getWidth()/2, 50, Graphics.HCENTER
| Graphics.TOP);
         g.drawString(String.valueOf(red), getWidth()/4, 100, Graphics. 
HCENTER | Graphics.TOP);
         g.drawString("红色", getWidth()/4, 120, Graphics.HCENTER | Graphics.TOP);
         g.drawString(String.valueOf(green), 2×getWidth()/4, 100, Graphics.HCENTER |
Graphics.TOP);
         g.drawString("绿色", 2×getWidth()/4, 120, Graphics.HCENTER | Grap- hics.TOP);
         g.drawString(String.valueOf(blue), 3×getWidth()/4, 100, Graphics. HCENTER 
Graphics.TOP);
         g.drawString("蓝色", 3×getWidth()/4, 120, Graphics.HCENTER | Grap- hics.TOP);
         g.drawImage(handImage, (colorType+1)×getWidth()/4, 130, Graphics.HCENTER |
Graphics.TOP);
      }
   }
}