package my.calc;import com.nokia.mid.ui.FullCanvas;import javax.microedition.lcdui.*;public class CalcCanvas extends FullCanvas{  /**退出按鈕*/  private Command cmdExit;  /**標題*/  private String title = "Calculator";  /**字體*/  private Font f;  /**顯示的數字*/  private int result = 0;  /**焦點編號*/  private int num = 0;  /**焦點圖片的坐標*/  private int x = 0;  private int y = 0;  /**默認構造方法*/  public CalcCanvas() {}  public void paint(Graphics g) {    f = g.getFont();    //繪制標題    g.drawString(title,getWidth() / 2,f.getHeight() / 2,Graphics.TOP|Graphics.HCENTER);    //繪制文本框    g.drawRect(3,24,172,20);    //繪制數字    String temp = Integer.toString(result);    g.drawString(temp,getWidth() - temp.length() / 2 - 3,30,Graphics.TOP|Graphics.RIGHT);    //繪制面板  }}