将调色板与 GridView 一起使用的问题

Question

当使用我的 GridView 实现 Palette 时，我无法滚动。

基本上，情况如下：GridView 中的每个项目都有一个标题栏和一个加载的图像。使用调色板，标题栏应该更改为调色板提取的提取颜色。

但发生的情况是，每次我向下滚动网格视图，然后向上滚动时，位置都会随着栏背景颜色而变化。

这是一个例子：

然后当我向下滚动并再次向上滚动时：

而且，颜色似乎也不太对劲，是吗？出于某种原因，它看起来只是选择了最后加载的颜色，有时甚至根本不加载，正如您看到的条形图。

我在我的专辑适配器中执行此操作，这是代码，希望有人可以指导我正确的方向。

public class AlbumAdapterNew extends ArrayAdapter<String> {

ArrayList<String> names;
Activity context;
ArrayList<String> coverPaths;
String coverPath;
Drawable img;
Bitmap bitmap;
ViewHolder mViewHolder = null;
ImageLoader imageLoader = ImageLoader.getInstance();
private RelativeLayout background;

static class ViewHolder {

    private TextView text;
    private ImageView image;

}

public AlbumAdapterNew(Activity context, ArrayList<String> names,
        ArrayList<String> coverPaths) {
    super(context, R.layout.albums_row, names);

    this.names = names;
    this.context = context;
    this.coverPaths = coverPaths;

    DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()

    .displayer(new FadeInBitmapDisplayer(500))

    .build();
    ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(
            context)

    .defaultDisplayImageOptions(defaultOptions)

    .build();
    ImageLoader.getInstance().init(config); // Do it on Application start

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub

    if (convertView == null) {
        mViewHolder = new ViewHolder();
        LayoutInflater vi = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = vi.inflate(R.layout.albums_row, parent, false);
        mViewHolder.text = (TextView) convertView
                .findViewById(R.id.albumTextView);
        mViewHolder.image = (ImageView) convertView
                .findViewById(R.id.album_photo);
        background = (RelativeLayout) convertView
                .findViewById(R.id.containerText);
        convertView.setTag(mViewHolder);

    }

    else {

        mViewHolder = (ViewHolder) convertView.getTag();

    }

    mViewHolder.text.setText(names.get(position));

    if (coverPaths.get(position) != null && !coverPaths.isEmpty()) {

        mViewHolder.image.setScaleType(ScaleType.CENTER_CROP);

        Glide.with(context).load("file:///" + coverPaths.get(position))
                .asBitmap()
                .into(new BitmapImageViewTarget(mViewHolder.image) {
                    @Override
                    protected void setResource(Bitmap resource) {
                        // Do bitmap magic here

                        Palette.from(resource).generate(
                                new Palette.PaletteAsyncListener() {
                                    public void onGenerated(Palette palette) {
                                        Palette.Swatch vibrantSwatch = palette
                                                .getVibrantSwatch();
                                        if (vibrantSwatch != null) {

                                            background
                                                    .setBackgroundColor(vibrantSwatch
                                                            .getRgb());

                                        }
                                    }
                                });

                        super.setResource(resource);
                    }
                });

    } else {

        mViewHolder.image.setScaleType(ScaleType.CENTER_INSIDE);

        imageLoader.displayImage("drawable://" + R.drawable.music_record,
                mViewHolder.image);

    }

    return convertView;
}

}

Answer 1

创建Palette 时，应在回调中将其保存到ViewHolder。除了 Palette 的创建成本很高之外，这始终使您的 Palette 实例与您绑定来自 ViewHolder 的数据时正在处理的网格项保持同步。

编辑：根据要求，一个例子。我手边没有带 SDK 的电脑，所以这是凭记忆写的，但它应该能让你朝着正确的方向前进！

    public class AlbumAdapterNew extends ArrayAdapter<String> {

    ArrayList<String> names;
    Activity context;
    ArrayList<String> coverPaths;
    String coverPath;
    Drawable img;
    Bitmap bitmap;
    ImageLoader imageLoader = ImageLoader.getInstance();

    static class ViewHolder {

        private TextView text;
        private ImageView image;
        private Palette palette;
        private RelativeLayout background;

    }

    public AlbumAdapterNew(Activity context, ArrayList<String> names,
                           ArrayList<String> coverPaths) {
        super(context, R.layout.albums_row, names);

        this.names = names;
        this.context = context;
        this.coverPaths = coverPaths;

        DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
            .displayer(new FadeInBitmapDisplayer(500))
            .build();

        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
            .defaultDisplayImageOptions(defaultOptions)
            .build();
        ImageLoader.getInstance().init(config); // Do it on Application start

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // This should be local so you don't get conflicts
        ViewHolder viewHolder;

        if (convertView == null) {
            viewHolder = new ViewHolder();
            LayoutInflater vi = LayoutInflater.from(parent.getContext());
            convertView = vi.inflate(R.layout.albums_row, parent, false);
            viewHolder.text = (TextView) convertView
                    .findViewById(R.id.albumTextView);
            viewHolder.image = (ImageView) convertView
                    .findViewById(R.id.album_photo);
            viewHolder.background = (RelativeLayout) convertView
                    .findViewById(R.id.containerText);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.text.setText(names.get(position));

        if (coverPaths.get(position) != null && !coverPaths.isEmpty()) {
            viewHolder.image.setScaleType(ScaleType.CENTER_CROP);
            Glide.with(context)
                    .load("file:///" + coverPaths.get(position))
                    .asBitmap()
                    .into(new BitmapImageViewTarget(viewHolder.image) {
                        @Override
                        protected void setResource(Bitmap resource) {
                            // Do bitmap magic here

                            if(viewHolder.palette != null) {
                                setViewBackgroundColor(viewHolder)
                            } else {
                                Palette.from(resource).generate(
                                    new Palette.PaletteAsyncListener() {
                                        public void onGenerated(Palette palette) {
                                            viewHolder.palette = palette;
                                            setViewBackgroundColor(vh);
                                        }
                                    });
                            }
                            super.setResource(resource);
                        }
                    });
        } else {
            mViewHolder.image.setScaleType(ScaleType.CENTER_INSIDE);
            imageLoader.displayImage("drawable://" + R.drawable.music_record,
                    mViewHolder.image);
        }

        return convertView;
    }

    private void setViewBackgroundColor(ViewHolder vh) {
        Palette.Swatch swatch = vh.palette.getVibrantSwatch();
        if(swatch != null) {
            vh.background.setBackgroundColor(swatch.getRgb());
        }
    }
}