private void addAppleBox(){int randomX = random.nextInt(xMaxBoxCount);int randomY = random.nextInt(yMaxBoxCount);for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == randomX){addAppleBox();break;}if(boxs.get(i).getY() == randomY){addAppleBox();break;}appleBox = new Box(randomX, randomY);} }

二、判断边界值

        //判断是否撞墙了if(headBox.getX() < 0 || headBox.getY() < 0 || headBox.getX() > xMaxBoxCount || headBox.getY() > yMaxBoxCount){currentState = State.LOSE;}//判断是否装到自己身上了for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == headBox.getX() && boxs.get(i).getY() == headBox.getY()){currentState = State.LOSE;}}isGroup = false;//判断是否吃到苹果了~~for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == appleBox.getX() && boxs.get(i).getY() == appleBox.getY()){isGroup = true;addAppleBox();}}

三、全部代码

package com.example.crazysnake;  import java.util.ArrayList;
import java.util.List;
import java.util.Random;import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
/*** CSDN博客：http://blog.csdn.net/dawanganban* @author 阳光小强*/
public class MySnake extends View {  private Paint paint; private Paint textPaint;private RectF rect;  private static int boxSize = 20;  private static int xMaxBoxCount;  //x轴方向最多的box数量private static int yMaxBoxCount;  //y轴方向最多的box数量private List<Box> boxs = new ArrayList<Box>(); private Box appleBox;private Random random;private boolean isGroup = false;private static final int[] colors = {  Color.RED,  Color.BLUE,   Color.GRAY,  Color.YELLOW  };  private enum Derectory{  LEFT,  RIGHT,  TOP,  BOTTOM;  }  private enum State{READY,    //就绪PAUSE,    //暂停RUNNING,  //运行LOSE      //失败}private Derectory currentDerect = Derectory.LEFT;  private State currentState = State.READY;private RefreshHandler mRefreshHandler = new RefreshHandler();class RefreshHandler extends Handler{@Overridepublic void handleMessage(Message msg) {MySnake.this.update();MySnake.this.invalidate();}public void sleep(long delayMillis) {this.removeMessages(0);sendMessageDelayed(obtainMessage(0), delayMillis);}}public MySnake(Context context, AttributeSet attrs) {  super(context, attrs);  paint = new Paint(); textPaint = new Paint();textPaint.setColor(Color.RED);textPaint.setTextSize(60);rect = new RectF(); random = new Random();  }  private void update(){if(currentState == State.RUNNING){move();mRefreshHandler.sleep(150);}}private void initData(){  Box box;  for(int i=xMaxBoxCount - 5; i<xMaxBoxCount; i++){  box = new Box(i, 3);  boxs.add(box);  }  }  @Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);xMaxBoxCount = (int) Math.floor(w / boxSize);yMaxBoxCount = (int) Math.floor(h / boxSize);}private float mDownX;  private float mDownY;  @Override  public boolean onTouchEvent(MotionEvent event) {System.out.println("onTouch");  switch (event.getAction()) {  case MotionEvent.ACTION_DOWN:  mDownX = event.getX();  mDownY = event.getY();  break;  case MotionEvent.ACTION_UP:  float disX = event.getX() - mDownX;  float disY = event.getY() - mDownY;  System.out.println("disX = " + disX);  System.out.println("dixY = " + disY);  if(Math.abs(disX) > Math.abs(disY)){  if(disX > 0){  if(currentDerect != Derectory.LEFT){currentDerect = Derectory.RIGHT;  }}else{  if(currentState != State.RUNNING){currentState = State.RUNNING;currentDerect = Derectory.LEFT;boxs.clear();initData();addAppleBox();update();}else if(currentDerect != Derectory.RIGHT){        currentDerect = Derectory.LEFT;  }}  }else{  if(disY > 0){  if(currentDerect != Derectory.TOP){currentDerect = Derectory.BOTTOM;  }}else{ if(currentDerect != Derectory.BOTTOM){currentDerect = Derectory.TOP;  }}  }  break;  }  return true;  }  private void move(){  Box headBox = new Box(0, 0);  switch (currentDerect) {case LEFT:  headBox = new Box(boxs.get(0).getX() - 1, boxs.get(0).getY());break;  case RIGHT:  headBox = new Box(boxs.get(0).getX() + 1, boxs.get(0).getY());  break;  case TOP:  headBox = new Box(boxs.get(0).getX(), boxs.get(0).getY() - 1); break;  case BOTTOM:  headBox = new Box(boxs.get(0).getX(), boxs.get(0).getY() + 1);break;  } //判断是否撞墙了if(headBox.getX() < 0 || headBox.getY() < 0 || headBox.getX() > xMaxBoxCount || headBox.getY() > yMaxBoxCount){currentState = State.LOSE;}//判断是否装到自己身上了for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == headBox.getX() && boxs.get(i).getY() == headBox.getY()){currentState = State.LOSE;}}isGroup = false;//判断是否吃到苹果了~~for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == appleBox.getX() && boxs.get(i).getY() == appleBox.getY()){isGroup = true;addAppleBox();}}boxs.add(0, headBox);if(!isGroup){boxs.remove(boxs.size() - 1);}}  private void addAppleBox(){int randomX = random.nextInt(xMaxBoxCount);int randomY = random.nextInt(yMaxBoxCount);for(int i=0; i<boxs.size(); i++){if(boxs.get(i).getX() == randomX){addAppleBox();break;}if(boxs.get(i).getY() == randomY){addAppleBox();break;}appleBox = new Box(randomX, randomY);}   }@Override  protected void onDraw(Canvas canvas) {  super.onDraw(canvas);  for(int i=0; i<boxs.size(); i++){  paint.setColor(colors[i % colors.length]);  rect.set(boxs.get(i).getX() * boxSize, boxs.get(i).getY() * boxSize, (boxs.get(i).getX() + 1) * boxSize, (boxs.get(i).getY() + 1) * boxSize);  canvas.drawRect(rect, paint);  } if(appleBox != null){paint.setColor(Color.RED);rect.set(appleBox.getX() * boxSize, appleBox.getY() * boxSize, (appleBox.getX() + 1) * boxSize, (appleBox.getY() + 1) * boxSize);canvas.drawRect(rect, paint);}if(currentState == State.READY){canvas.drawText("请向左滑动", (xMaxBoxCount * boxSize - textPaint.measureText("请向左滑动")) / 2,xMaxBoxCount * boxSize / 2, textPaint);}if(currentState == State.LOSE){canvas.drawText("失败！左滑继续", (xMaxBoxCount * boxSize - textPaint.measureText("失败！左滑继续")) / 2,(float)xMaxBoxCount * boxSize / 2, textPaint);canvas.drawText("长度:" + boxs.size() , (xMaxBoxCount * boxSize - textPaint.measureText("长度:" + boxs.size())) / 2,(float)xMaxBoxCount * boxSize / 4 * 3, textPaint);}}
}

CODE代码地址：https://code.csdn.net/lxq_xsyu/crazysnake