上一篇《是男人就下100层【第四层】——Crazy贪吃蛇（2）》实现了贪吃蛇绕着屏幕四周移动，这一篇我们来完成贪吃蛇的所有功能。
一、随机产生苹果
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;
/**
* ****博客：http://blog.****.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{
@Override
public 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);
}
} @Override
protected 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.****.net/lxq_xsyu/crazysnake