安卓贪吃蛇实现

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1. 概述

1.1 项目背景

近年来随着手机技术的不断发展古老的贪吃蛇游戏不能给与广大青少年的良好游戏体验，所以本文再基于古老的贪吃蛇游戏上对游戏进行了改进使得玩法更加多样有趣。

1.2 研究的主要内容

研究的主要内容包括对蛇如何进行控制，实现食物的随机生成，并且对蛇可以进行加速控制。游戏得分等

2. 相关技术

采用的技术有 多线程 自定义View 以及一个activity

3. 系统分析

此为一个新版的贪吃蛇游戏，设计的游戏需要蛇的移动、加速、增长、死亡功能。程文件主要包括src文件夹（Java源码）、res文件夹（资源文件）和AndroidMainfest.xml（程序清单）。软件主要由Activities，自定义view 组成 View主要用来绘制图形并进行逻辑的处理。Activity主要实现对蛇的控制和对用户的交互信息等

4. 系统设计

图1游戏组成

5. 系统实现

1、游戏界面

图2开始界面

图3

图4暂停界面

图5结束界面

图6穿墙界面

实现该模块的核心代码如下：

TileView.java

package cn.edu.zust.lihuan;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
public class TileView extends View {
    protected static int mTileSize;
    protected static int mXTileCount;
    protected static int mYTileCount;
    private static int mXOffset;
    private static int mYOffset;
    private Bitmap[] mTileArray;
    private int[][] mTileGrid;
    private final Paint mPaint = new Paint();
    public TileView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TileView);

        mTileSize = a.getInt(R.styleable.TileView_tileSize, 32);

        a.recycle();
    }
    public TileView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
    public void resetTiles(int tilecount) {
        mTileArray = new Bitmap[tilecount];
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        mXTileCount = (int) Math.floor(w / mTileSize);
        mYTileCount = (int) Math.floor(h / mTileSize);

        mXOffset = ((w - (mTileSize * mXTileCount)) / 2);
        mYOffset = ((h - (mTileSize * mYTileCount)) / 2);

        mTileGrid = new int[mXTileCount][mYTileCount];
        clearTiles();
    }
    public void loadTile(int key, Drawable tile) {
        Bitmap bitmap = Bitmap.createBitmap(mTileSize, mTileSize, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        tile.setBounds(0, 0, mTileSize, mTileSize);
        tile.draw(canvas);

        mTileArray[key] = bitmap;
    }
    public void clearTiles() {
        for (int x = 0; x < mXTileCount; x++) {
            for (int y = 0; y < mYTileCount; y++) {
                setTile(0, x, y);
            }
        }
    }
    public void setTile(int tileindex, int x, int y) {
        mTileGrid[x][y] = tileindex;
    }
    @Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        for (int x = 0; x < mXTileCount; x += 1) {
            for (int y = 0; y < mYTileCount; y += 1) {
                if (mTileGrid[x][y] > 0) {
                    canvas.drawBitmap(mTileArray[mTileGrid[x][y]],
                            mXOffset + x * mTileSize,
                            mYOffset + y * mTileSize,
                            mPaint);
                }
            }
        }

    }

}

Snake.java

package cn.edu.zust.lihuan;
import android.app.Activity;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Vibrator;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.TextView;
import static android.view.MotionEvent.ACTION_DOWN;
import static android.view.MotionEvent.ACTION_UP;
public class   Snake extends Activity {
    private SnakeView mSnakeView;
    private Button mBt_up, mBt_down, mBt_left, mBt_right, mBt_home;
    private Vibrator vibrator;
    private Resources r;
    private static String ICICLE_KEY = "snake-view";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(cn.edu.zust.lihuan.R.layout.snake_layout);
        mSnakeView = (SnakeView) findViewById(cn.edu.zust.lihuan.R.id.snake);
        mSnakeView.setTextView((TextView) findViewById(cn.edu.zust.lihuan.R.id.text));
        vibrator = (Vibrator) getSystemService(VIBRATOR_SERVICE);
        r = getResources();
        if (savedInstanceState == null) {
            mSnakeView.setMode(SnakeView.READY);
        } else {
            Bundle map = savedInstanceState.getBundle(ICICLE_KEY);
            if (map != null) {
                mSnakeView.restoreState(map);
            } else {
                mSnakeView.setMode(SnakeView.PAUSE);
                mSnakeView.setMODE(SnakeView.PAUSE);
            }
        }
        mBt_up = findViewById(cn.edu.zust.lihuan.R.id.up);
        mBt_down = findViewById(cn.edu.zust.lihuan.R.id.dowm);
        mBt_left = findViewById(cn.edu.zust.lihuan.R.id.left);
        mBt_right = findViewById(cn.edu.zust.lihuan.R.id.right);
        mBt_home = findViewById(cn.edu.zust.lihuan.R.id.home);
        mBt_up.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                switch (motionEvent.getAction()) {
                    case ACTION_DOWN:
                        mSnakeView.up();
                        vibrator.vibrate(30);
                        mSnakeView.addBuff();
                        break;
                    case ACTION_UP:
                        mSnakeView.deBuff();
                        break;
                }
                return false;
            }
        });
        mBt_down.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                switch (motionEvent.getAction()) {
                    case ACTION_DOWN:
                        mSnakeView.down();
                        vibrator.vibrate(30);
                        mSnakeView.addBuff();
                        break;
                    case ACTION_UP:
                        mSnakeView.deBuff();
                        break;
                }
                return false;
            }
        });
        mBt_left.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                switch (motionEvent.getAction()) {
                    case ACTION_DOWN:
                        mSnakeView.left();
                        vibrator.vibrate(30);
                        mSnakeView.addBuff();
                        break;
                    case ACTION_UP:
                        mSnakeView.deBuff();
                        break;
                }
                return false;
            }
        });
        mBt_right.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                switch (motionEvent.getAction()) {
                    case ACTION_DOWN:
                        mSnakeView.right();
                        vibrator.vibrate(30);
                        mSnakeView.addBuff();
                        break;
                    case ACTION_UP:
                        mSnakeView.deBuff();
                        break;
                }
                return false;
            }
        });
        mBt_home.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                changeHome();
                mSnakeView.star();
                vibrator.vibrate(300);
            }
        });
    }
    @Override
    protected void onPause() {
        super.onPause();
        // Pause the game along with the activity
        mSnakeView.setMode(SnakeView.PAUSE);
        changeHome();
        mSnakeView.setMODE(SnakeView.PAUSE);
    }
    @Override
    public void onSaveInstanceState(Bundle outState) {
        //Store the game state
        outState.putBundle(ICICLE_KEY, mSnakeView.saveState());
    }
    public void changeHome() {
        if (r != null) {
            if (mSnakeView.getMODE() == mSnakeView.PAUSE ||
                    mSnakeView.getMODE() == mSnakeView.READY || mSnakeView.getMODE() == mSnakeView.LOSE) {
                mBt_home.setBackground(r.getDrawable(R.drawable.btn_bg_home_selector));
            } else if (mSnakeView.getMODE() == mSnakeView.RUNNING) {
                mBt_home.setBackground(r.getDrawable(R.drawable.btn_bg_home2_selector));
            }
        } else {
        }
    }
}

SnakeView.java

 
package cn.edu.zust.lihuan;

import android.content.Context;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Random;

public class SnakeView extends TileView {
    private static final String TAG = "SnakeView";
    private int mMode = READY;
    public static final int PAUSE = 0;
    public static final int READY = 1;
    public static final int RUNNING = 2;
    public static final int LOSE = 3;
    private int mDirection = NORTH;
    private int mNextDirection = NORTH;
    private static final int NORTH = 1;
    private static final int SOUTH = 2;
    private static final int EAST = 3;
    private static final int WEST = 4;
    private static final int APPLE = 1;
    private static final int HEAD = 2;
    private static final int DEADHEAD = 3;
    private static final int BODY = 4;
    private static final int APPLE2 = 5;
    private static int MODE = READY;

    public static void setMODE(int MODE) {
        SnakeView.MODE = MODE;
    }

    public int getMODE() {
        return MODE;
    }

    private long mScore = 0;
    private long mMoveDelay = 100;
    private boolean mBuff = false;
    private int gorwTag = 1;

    /**
     * Give our snake some buff!
     */
    public void addBuff() {
        if (!mBuff) {
            mBuff = true;
            mMoveDelay /= 5;
            loadTile(APPLE2, r.getDrawable(R.drawable.redstar));

        }
    }

    public void deBuff() {
        if (mBuff) {
            mBuff = false;
            mMoveDelay *= 5;
        }
        loadTile(APPLE2, r.getDrawable(R.drawable.greenstar));
    }

    private long mLastMove;
    private TextView mStatusText;
    private ArrayList mSnakeTrail = new ArrayList();
    private ArrayList mAppleList = new ArrayList();
    private ArrayList mAppleList2 = new ArrayList();
    /**
     * Everyone needs a little randomness in their life
     */
    private static final Random RNG = new Random();
    private RefreshHandler mRedrawHandler = new RefreshHandler();
    Resources r = this.getContext().getResources();

    class RefreshHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            SnakeView.this.update();
            SnakeView.this.invalidate();
        }

        public void sleep(long delayMillis) {
            this.removeMessages(0);
            //     Toast.makeText(SnakeView.this.getContext(),"这是一个TOAST",Toast.LENGTH_SHORT).show();
            sendMessageDelayed(obtainMessage(0), delayMillis);
        }
    }

    public SnakeView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SnakeView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initSnakeView();
    }

    private void initSnakeView() {
        setFocusable(true);
        resetTiles(6);
        loadTile(HEAD, r.getDrawable(cn.edu.zust.lihuan.R.drawable.head));
        loadTile(APPLE, r.getDrawable(cn.edu.zust.lihuan.R.drawable.apple));
        loadTile(BODY, r.getDrawable(cn.edu.zust.lihuan.R.drawable.body));
        loadTile(DEADHEAD, r.getDrawable(cn.edu.zust.lihuan.R.drawable.deadhead));
        loadTile(APPLE2, r.getDrawable(R.drawable.redstar));
    }

    private void initNewGame() {
        mSnakeTrail.clear();
        mAppleList.clear();
        mAppleList2.clear();
        gorwTag = 1;
        // that's just turned north
        for (int i = 4; i > 0; i--) {
            mSnakeTrail.add(new Coordinate(i, 7));
        }
        mNextDirection = NORTH;
        // How many apples to start with
        for (int i = 0; i < 100; i++) {
            addRandomApple();
        }
        for (int i = 0; i < 5; i++) {
            addRandomApple2();
        }
        //init time of snake
        mMoveDelay = 300;
        mScore = 0;
    }

    private int[] coordArrayListToArray(ArrayList cvec) {
        int count = cvec.size();
        int[] rawArray = new int[count * 2];
        for (int index = 0; index < count; index++) {
            Coordinate c = cvec.get(index);
            rawArray[2 * index] = c.x;
            rawArray[2 * index + 1] = c.y;
        }
        return rawArray;
    }

    public Bundle saveState() {
        Bundle map = new Bundle();
        map.putIntArray("mAppleList", coordArrayListToArray(mAppleList));
        map.putIntArray("mAppleList2", coordArrayListToArray(mAppleList2));
        map.putInt("mDirection", Integer.valueOf(mDirection));
        map.putInt("mNextDirection", Integer.valueOf(mNextDirection));
        map.putLong("mMoveDelay", Long.valueOf(mMoveDelay));
        map.putLong("mScore", Long.valueOf(mScore));
        map.putIntArray("mSnakeTrail", coordArrayListToArray(mSnakeTrail));
        return map;
    }

    private ArrayList coordArrayToArrayList(int[] rawArray) {
        ArrayList coordArrayList = new ArrayList();
        int coordCount = rawArray.length;
        for (int index = 0; index < coordCount; index += 2) {
            Coordinate c = new Coordinate(rawArray[index], rawArray[index + 1]);
            coordArrayList.add(c);
        }
        return coordArrayList;
    }

    public void restoreState(Bundle icicle) {
        setMode(PAUSE);
        mAppleList = coordArrayToArrayList(icicle.getIntArray("mAppleList"));
        mAppleList2 = coordArrayToArrayList(icicle.getIntArray("mAppleList2"));
        mDirection = icicle.getInt("mDirection");
        mNextDirection = icicle.getInt("mNextDirection");
        mMoveDelay = icicle.getLong("mMoveDelay");
        mScore = icicle.getLong("mScore");
        mSnakeTrail = coordArrayToArrayList(icicle.getIntArray("mSnakeTrail"));
    }

    public void star() {
        if (mMode == READY | mMode == LOSE) {
            initNewGame();
            setMode(RUNNING);
            this.MODE = RUNNING;
            update();
        } else if (mMode == PAUSE) {
            setMode(RUNNING);
            this.MODE = RUNNING;
            update();
        } else if (mMode == RUNNING) {
            setMode(PAUSE);
            this.MODE = PAUSE;
            update();
        }
    }

    public void up() {
        if (mDirection != SOUTH) {
            mNextDirection = NORTH;
            loadTile(HEAD, r.getDrawable(R.drawable.head));
        }
    }

    public void down() {
        if (mDirection != NORTH) {
            mNextDirection = SOUTH;
            loadTile(HEAD, r.getDrawable(R.drawable.head2));
        }
    }

    public void left() {
        if (mDirection != EAST) {
            mNextDirection = WEST;
            loadTile(HEAD, r.getDrawable(R.drawable.head3));
        }
    }

    public void right() {
        if (mDirection != WEST) {
            mNextDirection = EAST;
            loadTile(HEAD, r.getDrawable(R.drawable.head4));
        }
    }

    public void setTextView(TextView newView) {
        mStatusText = newView;
    }

    public void setMode(int newMode) {
        int oldMode = mMode;
        mMode = newMode;

        if (newMode == RUNNING & oldMode != RUNNING) {
            mStatusText.setVisibility(View.INVISIBLE);
            update();
            return;
        }
        Resources res = getContext().getResources();
        CharSequence str = "";
        if (newMode == PAUSE) {
            str = res.getText(cn.edu.zust.lihuan.R.string.mode_pause);
        }
        if (newMode == READY) {
            str = res.getText(cn.edu.zust.lihuan.R.string.mode_ready);
        }
        if (newMode == LOSE) {
            str = res.getString(cn.edu.zust.lihuan.R.string.mode_lose_prefix) + mScore
                    + res.getString(cn.edu.zust.lihuan.R.string.mode_lose_suffix);
        }

        mStatusText.setText(str);
        mStatusText.setVisibility(View.VISIBLE);
    }

    private void addRandomApple() {
        Coordinate newCoord = null;
        boolean found = false;
        while (!found) {
            // Choose a new location for our apple
            int newX = 1 + RNG.nextInt(mXTileCount - 2);
            int newY = 1 + RNG.nextInt(mYTileCount - 2);
            newCoord = new Coordinate(newX, newY);
            // Make sure it's not already under the snake
            boolean collision = false;
            int snakelength = mSnakeTrail.size();
            for (int index = 0; index < snakelength; index++) {
                if (mSnakeTrail.get(index).equals(newCoord)) {
                    collision = true;
                }
            }
            found = !collision;
        }
        if (newCoord == null) {
            Log.e(TAG, "Somehow ended up with a null newCoord!");
        }
        mAppleList.add(newCoord);
    }

    private void addRandomApple2() {
        Coordinate newCoord = null;
        boolean found = false;
        while (!found) {
            int newX = 1 + RNG.nextInt(mXTileCount - 2);
            int newY = 1 + RNG.nextInt(mYTileCount - 2);
            newCoord = new Coordinate(newX, newY);
            boolean collision = false;
            int snakelength = mSnakeTrail.size();
            for (int index = 0; index < snakelength; index++) {
                if (mSnakeTrail.get(index).equals(newCoord)) {
                    collision = true;
                }
            }
            found = !collision;
        }
        if (newCoord == null) {
            Log.e(TAG, "Somehow ended up with a null newCoord!");
        }
        mAppleList2.add(newCoord);
    }

    public void update() {
        if (mMode == RUNNING) {
            long now = System.currentTimeMillis();
            if (now - mLastMove > mMoveDelay) {
                clearTiles();
                updateWalls();
                updateSnake();
                updateApples();
                updateApples2();
                mLastMove = now;
            }
            mRedrawHandler.sleep(mMoveDelay);
        }
    }

    private void updateWalls() {
        for (int x = 0; x < mXTileCount; x++) {
            setTile(DEADHEAD, x, 0);
            setTile(DEADHEAD, x, mYTileCount - 1);
        }
        for (int y = 1; y < mYTileCount - 1; y++) {
            setTile(DEADHEAD, 0, y);
            setTile(DEADHEAD, mXTileCount - 1, y);
        }
    }

    private void updateApples() {
        for (Coordinate c : mAppleList) {
            setTile(APPLE, c.x, c.y);
        }
    }

    private void updateApples2() {
        for (Coordinate c : mAppleList2) {
            setTile(APPLE2, c.x, c.y);
        }
    }

    private void updateSnake() {
        boolean growSnake = false;
        // grab the snake by the head
        Coordinate head = mSnakeTrail.get(0);
        Coordinate newHead = new Coordinate(1, 1);
        mDirection = mNextDirection;
        switch (mDirection) {
            case EAST: {
                newHead = new Coordinate(head.x + 1, head.y);
                break;
            }
            case WEST: {
                newHead = new Coordinate(head.x - 1, head.y);
                break;
            }
            case NORTH: {
                newHead = new Coordinate(head.x, head.y - 1);
                break;
            }
            case SOUTH: {
                newHead = new Coordinate(head.x, head.y + 1);
                break;
            }
        }
        if ((newHead.x < 1) || (newHead.x > mXTileCount - 2)
                ) {
            setMode(LOSE);
            return;

        } else if (newHead.y == 0) {//穿上面的墙

            newHead.y = mYTileCount - 2;
        } else if (newHead.y == mYTileCount - 1) {//穿下面的墙

            newHead.y = 1;
        }
        int snakelength = mSnakeTrail.size();
        for (int snakeindex = 0; snakeindex < snakelength; snakeindex++) {
            Coordinate c = mSnakeTrail.get(snakeindex);
            if (c.equals(newHead)) {
                setMode(LOSE);
                return;
            }
        }
        int applecount = mAppleList.size();
        int applecount2 = mAppleList2.size();
        for (int appleindex = 0; appleindex < applecount; appleindex++) {
            Coordinate c = mAppleList.get(appleindex);
            if (c.equals(newHead)) {
                mAppleList.remove(c);
                addRandomApple();
                mScore++;
                mMoveDelay *= 0.998;
                growSnake = true;
            }
        }
        for (int appleindex = 0; appleindex < applecount2; appleindex++) {
            Coordinate c = mAppleList2.get(appleindex);
            if (c.equals(newHead)) {
                gorwTag = 2;
                mAppleList2.remove(c);
                addRandomApple2();
                mScore += 5;
                //chenge time of snake
                mMoveDelay *= 0.998;
                growSnake = true;
            }
        }
        switch (gorwTag) {
            case 1:
                mSnakeTrail.add(0, newHead);
                break;

            case 2:
                for (int i = 0; i < 4; i++) {
                    mSnakeTrail.add(0, newHead);
                }
                gorwTag = 1;
                for (int i = 0; i < 4; i++) {
                    updateSnake();
                }
                break;
            default:
                break;
        }
        if (!growSnake) {
            mSnakeTrail.remove(mSnakeTrail.size() - 1);
        }
        // draw snake
        int index = 0;
        for (Coordinate c : mSnakeTrail) {
            if (index == 0) {
                setTile(HEAD, c.x, c.y);
            } else {
                setTile(BODY, c.x, c.y);
            }
            index++;
        }

    }

    private class Coordinate {
        public int x;
        public int y;

        public Coordinate(int newX, int newY) {
            x = newX;
            y = newY;
        }

        public boolean equals(Coordinate other) {
            if (x == other.x && y == other.y) {
                return true;
            }
            return false;
        }

        @Override
        public String toString() {
            return "Coordinate: [" + x + "," + y + "]";
        }
    }

}

snake_layout.xml

6. 总结

在程序设计的时候喜欢将界面与处理分开，这样降低耦合性，易于维护扩展。UI和游戏逻辑进行了分离， 它的实现方式就是，用父类TileView来实现比较基础的界面UI部分，而TileView类的子类SnakeView类完成了游戏控制逻辑部分，这样 就成功的将两者进行了分离，对后面的扩展和维护奠定了良好的基础。

github源码地址