Question

我制作了一个动态壁纸，当手机刷新时显示来自可绘制目录的图片如果打开一个应用程序，我们锁定手机时图像更改比解锁图像会改变，一切都很好这是我的代码

public class CustomWallpaper extends WallpaperService {

@Override
public Engine onCreateEngine() {
    return new WallpaperEngine();
}

class WallpaperEngine extends Engine {
    private int[] mImagesArray;
    private int mImagesArrayIndex = 0;
    private boolean mVisible = true;
    private String mImageScale = "Stretch to screen";
    private CustomWallpaperHelper customWallpaperHelper;

    public WallpaperEngine() {
        customWallpaperHelper = new CustomWallpaperHelper(getApplicationContext(), getResources());
        mImagesArray = new int[] {R.drawable.image_1,R.drawable.image_2,R.drawable.image_3,R.drawable.image_4,R.drawable.image_5,R.drawable.image_6,R.drawable.image_7,R.drawable.image_8,R.drawable.image_9,R.drawable.image_10,R.drawable.image_11,R.drawable.image_12,R.drawable.image_13,R.drawable.image_14,R.drawable.image_15,R.drawable.image_16,R.drawable.image_17,R.drawable.image_18,R.drawable.image_19,R.drawable.image_20,R.drawable.image_21,R.drawable.image_22,R.drawable.image_23,R.drawable.image_24,R.drawable.image_25,R.drawable.image_26,R.drawable.image_27,R.drawable.image_28,R.drawable.image_29,R.drawable.image_30,R.drawable.image_31,R.drawable.image_32};
    }

    @Override
    public void onVisibilityChanged(boolean visible) {
        super.onVisibilityChanged(visible);

        if (visible && mVisible != visible) {
            drawFrame();
        }

        mVisible = visible;
    }

    private void incrementCounter() {
        mImagesArrayIndex++;

        if (mImagesArrayIndex >= mImagesArray.length) {
            mImagesArrayIndex = 0;
        }
    }

    private void drawFrame() {
        final SurfaceHolder holder = getSurfaceHolder();

        Canvas canvas = null;

        try {
            canvas = holder.lockCanvas();

            if (canvas != null) {
                drawImage(canvas);
                incrementCounter();
            }
        } finally {
            if (canvas != null) {
                holder.unlockCanvasAndPost(canvas);
            }
        }
    }

    private void drawImage(Canvas canvas) {
        //Get the image and resize it
        Bitmap image = BitmapFactory.decodeResource(getResources(),
                mImagesArray[mImagesArrayIndex]);

        //Draw background
        customWallpaperHelper.setBackground(canvas);

        //Scale the canvas
        PointF mScale = customWallpaperHelper.getCanvasScale(mImageScale, image.getWidth(), image.getHeight());
        canvas.scale(mScale.x, mScale.y);

        //Draw the image on screen
        Point mPos = customWallpaperHelper.getImagePos(mScale, image.getWidth(), image.getHeight());
        canvas.drawBitmap(image, mPos.x, mPos.y, null);
    }
}
}

我的问题是如何随机显示图像

不像1.2.3.4.5.6.7 ......

但是例如9.15.20.4.35.1 ...

Answer 1

无需额外的方法来增加计数和检查。只需使用a 随机数介于 0和（size-1）之间。

Random rand=new Random();



     private void drawImage(Canvas canvas) {
//rand.nextInt(n) Returns a pseudo-random uniformly distributed int in 
//the half-open range [0, n). 

            //Get the image and resize it
            Bitmap image = BitmapFactory.decodeResource(getResources(),
                    mImagesArray[rand.nextInt(mImagesArray.length)]);

            //Draw background
            customWallpaperHelper.setBackground(canvas);

            //Scale the canvas
            PointF mScale = customWallpaperHelper.getCanvasScale(mImageScale, image.getWidth(), image.getHeight());
            canvas.scale(mScale.x, mScale.y);

            //Draw the image on screen
            Point mPos = customWallpaperHelper.getImagePos(mScale, image.getWidth(), image.getHeight());
            canvas.drawBitmap(image, mPos.x, mPos.y, null);
        }

这也可以帮助你..

Answer 2

更改

private void incrementCounter()
{
    mImagesArrayIndex++;

    if (mImagesArrayIndex >= mImagesArray.length) 
    {
        mImagesArrayIndex = 0;
    }
}

到

private void incrementCounter() 
{
    mImagesArrayIndex = new Random().nextInt(mImagesArray.length)
}

这将为您提供mImagesArray

大小的随机索引

如何随机显示动态壁纸中的图像

2 个答案: