enemytanksprite.java

1. 创建一个独立的线程类

package tankgame611;
import java.applet.Applet;
import java.awt.Image;
import java.util.Random;

public class EnemyTankSprite extends SpriteDrawing{
  int AppletWidth, AppletHeight;
  int enemyTankWidth, enemyTankHeight;
  int direction;
  int enemyTankX, enemyTankY;
  Image enemyTankImg[];
  Applet GameApplet;
  Thread newThread;
  Random rand;
  static int speed = 2;

  public EnemyTankSprite(Image[] enemyTankImg,
                         int enemyTankX,
                         int enemyTankY,
                         Applet GameApplet){
    super(enemyTankImg, enemyTankX, enemyTankY, GameApplet); //调用父类的创建方法
    this.enemyTankX = enemyTankX;
    this.enemyTankY = enemyTankY;
    this.enemyTankImg = enemyTankImg;
    enemyTankWidth=enemyTankImg[0].getWidth(GameApplet);
    enemyTankHeight=enemyTankImg[0].getHeight(GameApplet);
    this.GameApplet=GameApplet;
    AppletWidth=GameApplet.getWidth();
    AppletHeight=GameApplet.getHeight();
    setVisible(true);
    setActive(true);
    rand=new Random();
  }
  public void updateState(int SpriteDirection){
    //移动坦克

    switch (SpriteDirection) {
      case 0: //左
        enemyTankX = this.getX() - speed;
        if (enemyTankX < 0) { //设定坦克的左边界
          enemyTankX = 0;
          this.direction = 1;
        }
        break;
      case 1: //右
        enemyTankX = this.getX() + speed;
        if (enemyTankX >AppletWidth - enemyTankWidth) { //设定坦克的右边界
          enemyTankX = AppletWidth - enemyTankWidth;
          this.direction = 0;
        }
        break;
      case 2: //上
        enemyTankY = this.getY() - speed;
        if (enemyTankY < 0) { //设定坦克的上边界
          enemyTankY = 0;
          this.direction = 3;
        }
        break;
      case 3: //下
        enemyTankY = this.getY() + speed;
        if (enemyTankY > AppletHeight - enemyTankHeight) { //设定坦克的下边界
          enemyTankY = AppletHeight - enemyTankHeight;
          this.direction = 2;
        }
        break;
    }
    this.setPos(enemyTankX,enemyTankY);
  }
public int getTankDirection(){
  return direction;
}
public void setTankDirection(int direction){
   this.direction = direction;
}
}