RecyclerView列表項(xiàng)滑動(dòng)縮放效果

要實(shí)現(xiàn)RecyclerView列表項(xiàng)滑動(dòng)縮放效果，可以通過(guò)自定義RecyclerView的ItemDecoration來(lái)實(shí)現(xiàn)。

首先，創(chuàng)建一個(gè)自定義的ItemDecoration類，繼承自RecyclerView.ItemDecoration，并重寫(xiě)getItemOffsets()和onDraw()方法。在getItemOffsets()方法中設(shè)置列表項(xiàng)之間的間距，然后在onDraw()方法中根據(jù)列表項(xiàng)的位置和滑動(dòng)偏移來(lái)動(dòng)態(tài)設(shè)置列表項(xiàng)的縮放效果。

public class ScaleItemDecoration extends RecyclerView.ItemDecoration {
    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.set(20, 20, 20, 20); // 設(shè)置列表項(xiàng)之間的間距
    }

    @Override
    public void onDraw(@NonNull Canvas c, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
        super.onDraw(c, parent, state);

        int itemCount = parent.getAdapter().getItemCount();
        for (int i = 0; i < itemCount; i++) {
            View child = parent.getChildAt(i);
            if (child != null) {
                float scale = calculateScale(parent, child); // 計(jì)算縮放比例
                child.setScaleX(scale);
                child.setScaleY(scale);
            }
        }
    }

    private float calculateScale(RecyclerView parent, View child) {
        int childWidth = child.getWidth();
        int parentWidth = parent.getWidth();
        int center = parentWidth / 2;
        int childCenter = child.getLeft() + childWidth / 2;
        int distance = Math.abs(center - childCenter);

        float scale = 1 - (float) distance / parentWidth * 0.5f; // 根據(jù)距離計(jì)算縮放比例
        return Math.max(scale, 0.5f); // 縮放比例最小為0.5
    }
}

然后，在Activity或Fragment中，將創(chuàng)建的ScaleItemDecoration類添加到RecyclerView中即可實(shí)現(xiàn)滑動(dòng)縮放效果。

RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.addItemDecoration(new ScaleItemDecoration());
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

通過(guò)以上步驟，就可以實(shí)現(xiàn)RecyclerView列表項(xiàng)滑動(dòng)縮放效果。根據(jù)列表項(xiàng)的位置和滑動(dòng)偏移來(lái)動(dòng)態(tài)設(shè)置列表項(xiàng)的縮放效果，使列表項(xiàng)隨著滑動(dòng)而縮放。