hitmouse_canvas.java

J2ME下的图形编程实例,包括简单图形的绘制,以及一个打老鼠的游戏实现.可为学习参考.

package ch05;

import java.util.*;
import java.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;

public class Hitmouse_Canvas
    extends GameCanvas {
  //获取绘制上下文
  Graphics g = getGraphics();

  //创建一个由于控制老鼠出现的随机对象
  Random ra = new Random();

  //获取屏幕宽度和高度
  int w = getWidth();
  int h = getHeight();

  //声明一个代表老鼠出现区域的变量
  int fang; //取值1～9

  //声明一个代表老鼠出现次数的变量
  static int bornmouse;

  //声明一个代表打中老鼠次数的变量
  static int killedmouse;

  //声明一个控制绘制的Timer对象
  private Timer tm;

  //声明一个实现绘制的TimerTask对象
  private TimerTask tt;

  //构造器
  public Hitmouse_Canvas() throws IOException {
    super(false);
  }

  //启动线程方法
  public void start() {
    //启动使老鼠出现和擦除的线程
    tm = new Timer();
    tt = new Benben();
    tm.scheduleAtFixedRate(tt, 0, 1000);
  }

  //创建一个任务器
  public class Benben
      extends TimerTask {
    public void run() {
      drawBack();
      drawArea();
      try {
        Thread.sleep(Hitmouse_MIDlet.time);
      }
      catch (Exception e) {
        e.printStackTrace();
      }
      bornmouse++;
    }
  }

  //填充背景
  public void drawBack() {
    g.setColor(0x000000);
    g.fillRect(0, 0, getWidth(), getHeight());
    flushGraphics();
  }

  //画板上绘制图形
  private void drawArea() {
    //随机选取一个区域
    int in = ( (ra.nextInt() >>> 1) % 3);
    int it = ( (ra.nextInt() >>> 1) % 3);
    if (in == 0 & it == 0) {
      fang = 1;
    }
    if (in == 1 & it == 0) {
      fang = 2;
    }
    if (in == 2 & it == 0) {
      fang = 3;
    }
    if (in == 0 & it == 1) {
      fang = 4;
    }
    if (in == 1 & it == 1) {
      fang = 5;
    }
    if (in == 2 & it == 1) {
      fang = 6;
    }
    if (in == 0 & it == 2) {
      fang = 7;
    }
    if (in == 1 & it == 2) {
      fang = 8;
    }
    if (in == 2 & it == 2) {
      fang = 9;
    }
    //画圆老鼠洞方法
    g.setColor(0xffffff);
    g.fillArc(in * (w / 3), it * (h / 3), w / 3, h / 3, 20, 360);
    drawMouse(in * (w / 3), it * (h / 3));
    flushGraphics();
  }

  //画老鼠方法
  private void drawMouse(int x, int y) {
    g.setColor(0x000000);
    g.fillArc(12 + x, 5 + y, 15, 15, 20, 360);
    g.fillArc(35 + x, 5 + y, 15, 15, 20, 360);
    g.fillArc(17 + x, 15 + y, 28, 28, 20, 360);
    g.setColor(0xff00ff);
    g.fillArc(25 + x, 21 + y, 7, 7, 20, 360);
    g.fillArc(35 + x, 21 + y, 7, 7, 20, 360);
    g.setColor(0x00ff00);
    g.fillArc(28 + x, 33 + y, 10, 5, 20, 360);
    flushGraphics();
  }

  //画一个被打中后的老鼠
  public void drawNewMouse(int x, int y) {
    g.setColor(0x00ff00);
    g.fillArc(x, y, w / 3, h / 3, 20, 360);
    drawMouse(x, y);
    g.setColor(0xff0000);
    g.fillRect(x + 25, y + 8, 15, 18);
    g.setColor(0xff00ff);
    g.fillArc(x + 25, y + 8, 15, 5, 20, 360);
    g.setColor(0xff00ff);
    g.fillArc(x + 25, y + 23, 15, 5, 20, 360);
    g.setColor(0xff00ff);
    g.fillRect(x + 40, y + 15, 30, 8);
    g.setColor(0xffff00);
    g.fillArc(x + 55, y + 15, 3, 8, 20, 360);
    flushGraphics();
  }

  //响应按键事件
  protected void keyPressed(int key) {
    switch (key) {
      case KEY_NUM1:
        if (fang == 1) {
          drawNewMouse(0, 0);
          killedmouse++;
        }
        break;
      case KEY_NUM2:
        if (fang == 2) {
          drawNewMouse(w / 3, 0);
          killedmouse++;
        }
        break;
      case KEY_NUM3:
        if (fang == 3) {
          drawNewMouse(w / 3 * 2, 0);
          killedmouse++;
        }
        break;
      case KEY_NUM4:
        if (fang == 4) {
          drawNewMouse(0, h / 3);
          killedmouse++;
        }
        break;
      case KEY_NUM5:
        if (fang == 5) {
          drawNewMouse(w / 3, h / 3);
          killedmouse++;
        }
        break;
      case KEY_NUM6:
        if (fang == 6) {
          drawNewMouse(w / 3 * 2, h / 3);
          killedmouse++;
        }
        break;
      case KEY_NUM7:
        if (fang == 7) {
          drawNewMouse(0, h / 3 * 2);
          killedmouse++;
        }
        break;
      case KEY_NUM8:
        if (fang == 8) {
          drawNewMouse(w / 3, h / 3 * 2);
          killedmouse++;
        }
        break;
      case KEY_NUM9:
        if (fang == 9) {
          drawNewMouse(w / 3 * 2, h / 3 * 2);
          killedmouse++;
        }
        break;
    }
  }
}