用Android studio写一个贪吃蛇游戏代码

很好，下面是一个简单的贪吃蛇游戏的 Android Studio 代码示例：

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

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

public class SnakeGameView extends SurfaceView implements SurfaceHolder.Callback {
    private static final int MAX_SNAKE_LENGTH = 200;
    private static final int SNAKE_BLOCK_SIZE = 20;
    private static final int GAME_REFRESH_RATE = 100;
    private static final int MAX_GAME_SPEED = 40;
    private static final int MIN_GAME_SPEED = 5;

    private SurfaceHolder holder;
    private Context context;
    private SnakeThread snakeThread;
    private Paint paint;
    private ArrayList<SnakeBlock> snakeBlocks;
    private SnakeDirection snakeDirection;
    private int gameSpeed;
    private boolean gameOver;
    private SnakeBlock foodBlock;

    public SnakeGameView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
        holder = getHolder();
        holder.addCallback(this);

        paint = new Paint();
        paint.setColor(Color.WHITE);
        paint.setStyle(Paint.Style.FILL);

        snakeBlocks = new ArrayList<>();
        snakeDirection = SnakeDirection.RIGHT;
        gameSpeed = MAX_GAME_SPEED;
        gameOver = false;

        // Add the initial snake blocks
        int x = 10 * SNAKE_BLOCK_SIZE;
        int y = 10 * SNAKE_BLOCK_SIZE;
        for (int i = 0; i < 5; i++) {
            snakeBlocks.add(new SnakeBlock(x + i * SNAKE_BLOCK_SIZE, y));
        }

        // Generate the first food block
        generateFoodBlock();
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        snakeThread = new SnakeThread();
        snakeThread.start();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {}

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        snakeThread.stopThread();
    }

    private void update() {
        // Move the snake head in the current direction
        int headX = snakeBlocks.get(0).getX();
        int headY = snakeBlocks.get(0).getY();
        switch (snakeDirection) {
            case UP:
                headY -= SNAKE_BLOCK_SIZE;
                break;
            case DOWN:
                headY += SNAKE_BLOCK_SIZE;
                break;
            case LEFT:
                headX -= SNAKE_BLOCK_SIZE;
                break;
            case RIGHT:
                headX += SNAKE_BLOCK_SIZE;
                break;
        }

        // Check if the snake has collided with the walls or itself
        if (headX < 0 || headX >= getWidth() || headY < 0 || headY >= getHeight()) {
            gameOver = true;
            return;
        }
        for (int i = 1; i < snakeBlocks.size(); i++) {
            if (snakeBlocks.get(i).getX() == headX && snakeBlocks.get(i).getY() == headY) {
                gameOver = true;
                return;
            }
        }

        // Check if the snake has eaten the food block
        if (headX == foodBlock.getX() && headY == foodBlock.getY()) {
            snakeBlocks.add(0, foodBlock);
            generateFoodBlock();

            // Increase the game speed (up to a maximum)
            gameSpeed = Math.max(MIN_GAME_SPEED, gameSpeed - 1);
        } else {
            // Move the snake blocks forward
            for (int i = snakeBlocks.size() - 1; i > 0; i--) {
                snakeBlocks.get(i).setX(snakeBlocks.get(i - 1).getX());
                snakeBlocks.get(i).setY(snakeBlocks.get(i - 1).getY());
            }
        }

        // Move the snake head
        snakeBlocks.get(0).setX(headX);
        snakeBlocks.get(0).setY(headY);
    }

    private void generateFoodBlock() {
        Random random = new Random();
        int x = random.nextInt(getWidth() / SNAKE_BLOCK_SIZE) * SNAKE_BLOCK_SIZE;
        int y = random.nextInt(getHeight() / SNAKE_BLOCK_SIZE) * SNAKE_BLOCK_SIZE;
        foodBlock = new SnakeBlock(x, y);
    }

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);

        // Draw the snake blocks
        for (SnakeBlock block : snakeBlocks) {
            canvas.drawRect(block.getX(), block.getY(),
                    block.getX() + SNAKE_BLOCK_SIZE, block.getY() + SNAKE_BLOCK_SIZE, paint);
        }

        // Draw the food block
        canvas.drawRect(foodBlock.getX(), foodBlock.getY(),
                foodBlock.getX() + SNAKE_BLOCK_SIZE, foodBlock.getY() + SNAKE_BLOCK_SIZE, paint);
    }

    public void setSnakeDirection(SnakeDirection direction) {
        if (!gameOver && direction != snakeDirection.opposite()) {
            snakeDirection = direction;
        }
    }

    private class SnakeThread extends Thread {
        private boolean running;

        public SnakeThread() {
            running = true;
        }

        public void stopThread() {
            running = false;
        }

        @Override
        public void run() {
            while (running) {
                long startTime = System.currentTimeMillis();

                update();
                Canvas canvas = holder.lockCanvas();
                if (canvas != null) {
                    draw(canvas);
                    holder.unlockCanvasAndPost(canvas);
                }

                long timeElapsed = System.currentTimeMillis() - startTime;
                try {
                    Thread.sleep(Math.max(0, GAME_REFRESH_RATE - gameSpeed * timeElapsed));
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

enum SnakeDirection {
    UP, DOWN, LEFT, RIGHT;

    public SnakeDirection opposite() {
        switch (this) {
            case UP:
                return DOWN;
            case DOWN:
                return UP;
            case LEFT:
                return RIGHT;
            case RIGHT:
                return LEFT;
        }
        return null;
    }
}

class SnakeBlock {
    private int x;
    private int y;

    public SnakeBlock(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }
}

这个示例代码实现了一个简单的贪吃蛇游戏，可以在 Android Studio 中创建一个新的项目，将上述代码复制到 `MainActivity.java` 文件中，并在 `activity_main.xml` 文件中添加一个 `SnakeGameView` 的自定义视图即可开始游戏。