如何更改ImageCardView上信息区域的背景颜色？

Question

我正在尝试在选择卡时更改 Android Leanback Library中ImageCardView上infoArea的背景颜色.目前我尝试过的是改变OnItemViewSelectedListener中的背景.这会更改背景,但不会清除以前选择的项目.

private final class ItemViewSelectedListener implements OnItemViewSelectedListener {
        @Override
        public void onItemSelected(Presenter.ViewHolder itemViewHolder, Object item,
                                   RowPresenter.ViewHolder rowViewHolder, Row row) {
            if (item instanceof Video) {
                mBackgroundURI = ((Video) item).getBackgroundImageURI();
                startBackgroundTimer();
                ((ImageCardView) itemViewHolder.view)
                        .setInfoAreaBackgroundColor(getResources().getColor(R.color.dark_blue_grey));
            }
        }
    }

我想实现这样的目标:

有任何想法吗？谢谢.

Answer 1

我找到了一个更简单的解决方案,我只是跟踪当前选择的视图,然后根据它更改背景区域.

private final class ItemViewSelectedListener implements OnItemViewSelectedListener {

        private ImageCardView currentlySelectedView = null;

        @Override
        public void onItemSelected(Presenter.ViewHolder itemViewHolder, Object item,
                                   RowPresenter.ViewHolder rowViewHolder, Row row) {
            if (item instanceof Video) {
                mBackgroundURI = ((Video) item).getBackgroundImageURI();
                startBackgroundTimer();

                if (currentlySelectedView != null) {
                    currentlySelectedView.setInfoAreaBackgroundColor(
                            getResources().getColor(R.color.lb_basic_card_info_bg_color));
                }

                currentlySelectedView = (ImageCardView) itemViewHolder.view;
                currentlySelectedView
                        .setInfoAreaBackgroundColor(getResources().getColor(R.color.dark_blue_grey));
            }
        }
    }

Answer 2

我通过扩展ImageCardView来实现这一目的,以保持自定义选定的颜色.

public static class CustomImageCardView extends ImageCardView {

    private int mColor;

    public CustomImageCardView(Context context) {
        super(context);
    }

    public CustomImageCardView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

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

    public int getCustomSelectedSwatch() {
        return mColor;
    }

    public void setCustomColor(int color) {
        mColor = color;
    }
}

我保持默认的背景颜色,默认选择的颜色作为我的演示者中的成员变量.

private final int mDefaultInfoBackgroundColor;
private final int mDefaultSelectedInfoBackgroundColor;

并覆盖卡片图像视图的setSelected方法:

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent) {
    mContext = parent.getContext();

    final CustomImageCardView cardView = new CustomImageCardView(mContext) {
        @Override
        public void setSelected(boolean selected) {
            if (getCustomColor() != 0 && selected) {
                setInfoAreaBackgroundColor(getCustomColor());
            } else setInfoAreaBackgroundColor(selected ? mDefaultSelectedInfoBackgroundColor : mDefaultInfoBackgroundColor);
            super.setSelected(selected);
        }
    };

    cardView.setFocusable(true);
    cardView.setFocusableInTouchMode(true);
    return new ViewHolder(cardView);
}

如果您有任何疑问,请告诉我!