displayable1.java.bak

这是一个利用SWITCH语句实现图片之间相互切换的例子适合初学者学习

import javax.microedition.lcdui.*;
import com.nokia.mid.ui.FullCanvas;

public class Displayable1 extends FullCanvas implements CommandListener {
  Image image2,image1,image3,image4,image5,image6;
  int index = 1;
  public Displayable1() {
    try {
      image1 = Image.createImage("/image/menu1.png");
      image2 = Image.createImage("/image/menu2.png");
      image3 = Image.createImage("/image/01.png");
      image4 = Image.createImage("/image/02.png");
      image5 = Image.createImage("/image/03.png");
      image6 = Image.createImage("/image/04.png");
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }

  private void jbInit() throws Exception {
    // Set up this Displayable to listen to command events
    setCommandListener(this);
    // add the Exit command
    addCommand(new Command("Exit", Command.EXIT, 1));
  }

  public void commandAction(Command command, Displayable displayable) {
    /** @todo Add command handling code */
    if (command.getCommandType() == Command.EXIT) {
// stop the MIDlet
      qq.quitApp();
    }
  }

  protected void paint(Graphics g) {
    g.setColor(255,255,255);
    g.fillRect(0,0,getWidth(),getHeight()); 
    g.drawImage(image2,getWidth()/2,getHeight()/2,g.VCENTER | g.HCENTER);
    switch(index){
      case 1:
        g.drawImage(image1, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;
      case 2:
        g.drawImage(image2, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;

      case 3:
        g.drawImage(image3, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;
      case 4:
        g.drawImage(image4, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;
      case 5:
        g.drawImage(image5, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;
      case 6:
        g.drawImage(image6, getWidth() / 2, getHeight() / 2,
                    g.VCENTER | g.HCENTER);
        break;
    }

  }

  protected void keyPressed(int keyCode){
  int gameAc = getGameAction(keyCode);
//    if (gameAc == Canvas.FIRE) {
//      switch (index) {
//        case 1:
//          index = 1;
//          break;
//        case 2:
//          index = 2;
//          break;
//        case 3:
//          index = 3;
//          break;
//        case 4:
//          index = 4;
//          break;
//        case 5:
//          index = 5;
//          break;
//        case 6:
//          index = 6;
//          break;
//      }
//      
//    }
    if((keyCode == Canvas.KEY_NUM2)||(gameAc == Canvas.UP)){
     //判断是否移动到第一个选项
     if(index == 1){
       index = 6;
     }else{
       index--;
     }
   }
   //按下的是数字键8
   if((keyCode == Canvas.KEY_NUM8)||(gameAc == Canvas.DOWN)){
     //判断是否移动到第四个选项
     if(index == 6){
       index = 1;
     }else{
       index++;
     }
   }
     repaint();
  }


}