结合CoverFlow和通用图像加载器

Question

我正在使用fancyCoverFlow和universalImageLoader来显示我的自定义3D图库:D类似下图.我的问题是它没有在下载时显示图像,除非我在画廊图片之间滑动并且该图片在屏幕上隐藏,并且在下次显示图像时出现但是在UniversalImageLoader的样本中,下载的图像在下载后立即显示.

这是我的适配器的getView代码:

 public View getView(int position, View view, ViewGroup parent) {


    RoundedImageView photo = (RoundedImageView) view;
    if (photo == null) {
        photo = (RoundedImageView) inflater.inflate(R.layout.row_gallery_latest_issue_item, parent, false);
    }
    try {
        System.out.println("Test is good");
        ImageLoaderHelper.configureCacheableImage(mContext, photo, latestBook.get(position).getImageUrl(),
                R.drawable.avatar_issue, null);
    } catch (NullPointerException e) {
        photo.setImageResource(R.drawable.avatar_issue);
        e.printStackTrace();
    }

    return createReflectedImages(photo);
}

它与UniversalImageLoader完全相同Sample预计我有一个TryCatche和CreateReflectedImage(它使我们的ImageView反射)

,还有一件我的ImageLoaderHelper:

public class ImageLoaderHelper {
public static void configureCacheableImage(Context context, ImageView imageView
        , String imageUrl, Integer defaultImageResourceId
        , ImageLoadingListener imageLoadingListener) {
    ImageLoader imageLoader = ImageLoader.getInstance();
    DisplayImageOptions.Builder builder = new DisplayImageOptions.Builder();
    builder.displayer(
            new SimpleBitmapDisplayer())
            .cacheOnDisc(true)
            .cacheInMemory(true)
            .resetViewBeforeLoading(true)
            .imageScaleType(ImageScaleType.IN_SAMPLE_INT)
            .bitmapConfig(Bitmap.Config.RGB_565);
    if (defaultImageResourceId != null)
        builder.showImageOnFail(defaultImageResourceId).showImageForEmptyUri(defaultImageResourceId).showStubImage(defaultImageResourceId);
    if (!imageLoader.isInited())
        imageLoader.init(ImageLoaderConfiguration.createDefault(context));
    imageLoader.displayImage(imageUrl, imageView, builder.build(), imageLoadingListener);
}

}

更新:

经过一天的调试后,我找到了一条线索问题出在我的适配器上但是我不知道如何解决它!

这是CreateReflectedImages()的代码:

   public ImageView createReflectedImages(RoundedImageView image) {

    RoundedDrawable drawable = (RoundedDrawable) image.getDrawable();
    Bitmap originalImage = drawable.toBitmap();

    int width = originalImage.getWidth();
    int height = originalImage.getHeight();

    Matrix matrix = new Matrix();
    matrix.preScale(1, -1);

    Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
            height / 2, width, height / 2, matrix, false);

    Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
            (height + height / 2), Config.ARGB_8888);

    Canvas canvas = new Canvas(bitmapWithReflection);

    canvas.drawBitmap(originalImage, 0, 0, null);

    canvas.drawBitmap(reflectionImage, 0, height, null);

    Paint paint = new Paint();
    LinearGradient shader = new LinearGradient(0, height, 0, bitmapWithReflection.getHeight()
            , 0x70ffffff, 0x00ffffff, TileMode.CLAMP);

    paint.setShader(shader);

    paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));

    canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
            , paint);

    RoundedImageView imageView = new RoundedImageView(mContext);
    imageView.setImageBitmap(bitmapWithReflection);
    imageView.setLayoutParams(new ImageGallery3D.LayoutParams(GeneralHelper.dp(180), GeneralHelper.dp(240)));//width and height of Image
    return imageView;
}

Answer 1

问题是你有 2 个独立的 imageview 实例浮动。第一个是在getView中创建的，第二个是在createReflectedImage中创建的。所以基本上，当图像下载完成时，一个新的图像视图已经取代了它，并且下载的图像被加载到不再可见（甚至可能存在）的图像中。它第二次正确加载的原因（在滚动到屏幕外之后）是因为延迟要低得多，因为它是从内存中加载的，而不是从网络或其他地方加载的，所以当 RoundedDrawable drawable = (RoundedDrawable) image.getDrawable(); 时 它实际上有您想要的图像，而不仅仅是占位符！

public View getView(int position, View view, ViewGroup parent) {


    RoundedImageView photo = (RoundedImageView) view;
    ...
        /*
         *Passing first instance of photo into ImageLoaderHelper
         */

    ImageLoaderHelper.configureCacheableImage(mContext, photo, latestBook.get(position).getImageUrl(),
                R.drawable.avatar_issue, null);
    ...
    //
    //Returns the new instance of RoundedImageView that ImageLoader is not aware of to the adapter
    //
    return createReflectedImages(photo);
}

public ImageView createReflectedImages(RoundedImageView image) {
    ...

    RoundedImageView imageView = new RoundedImageView(mContext);
    imageView.setImageBitmap(bitmapWithReflection);
    imageView.setLayoutParams(new ImageGallery3D.LayoutParams(GeneralHelper.dp(180), GeneralHelper.dp(240)));//width and height of Image

    //Returning a new instance of imageView
    return imageView;
}

在 createReflectedImages 中不要返回 imageView，而是返回“image”。然后实现传递给 ImageLoaderHelper 的回调，该回调在图像成功加载后调用 createReflectedImages 以应用效果。