RecycleView收起或鋪開過度絲滑效果

直接上代碼：

public class AnimUtils {
    private final static int DURATION = 450;

    public static void zoom(View view, boolean isZoomAnim) {
        if (isZoomAnim) {
            AnimatorSet set = new AnimatorSet();
            set.playTogether(
                    ObjectAnimator.ofFloat(view, "scaleX", 1f, 1.12f),
                    ObjectAnimator.ofFloat(view, "scaleY", 1f, 1.12f)
            );
            set.setDuration(DURATION);
            set.start();
        }
    }

    public static void disZoom(View view, boolean isZoomAnim) {
        if (isZoomAnim) {
            AnimatorSet set = new AnimatorSet();
            set.playTogether(
                    ObjectAnimator.ofFloat(view, "scaleX", 1.12f, 1f),
                    ObjectAnimator.ofFloat(view, "scaleY", 1.12f, 1f)
            );
            set.setDuration(DURATION);
            set.start();
        }
    }

    /**
     * 箭頭旋轉動畫
     *
     * @param arrow
     * @param flag
     */
    public static void rotateArrow(ImageView arrow, boolean flag) {
        float pivotX = arrow.getWidth() / 2f;
        float pivotY = arrow.getHeight() / 2f;
        // flag爲true則向上
        float fromDegrees = flag ? 180f : 180f;
        float toDegrees = flag ? 360f : 360f;
        //旋轉動畫效果   參數值 旋轉的開始角度  旋轉的結束角度  pivotX x軸伸縮值
        RotateAnimation animation = new RotateAnimation(fromDegrees, toDegrees,
                pivotX, pivotY);
        //該方法用於設置動畫的持續時間，以毫秒爲單位
        animation.setDuration(350);
        //啓動動畫
        arrow.startAnimation(animation);
    }

    public static void expand(final View view) {
        view.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        final int viewHeight = view.getMeasuredHeight();
        view.getLayoutParams().height = 0;
        view.setVisibility(View.VISIBLE);

        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                if (interpolatedTime == 1) {
                    view.getLayoutParams().height = ViewGroup.LayoutParams.WRAP_CONTENT;
                } else {
                    view.getLayoutParams().height = (int) (viewHeight * interpolatedTime);
                }
                view.requestLayout();
            }
        };
        animation.setDuration(300);
        animation.setInterpolator(new FastOutLinearInInterpolator());
        view.startAnimation(animation);
    }

    public static void collapse(final View view) {
        //view.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        final int viewHeight = view.getMeasuredHeight();

        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                if (interpolatedTime == 1) {
                    view.setVisibility(View.GONE);
                } else {
                    view.getLayoutParams().height = viewHeight - (int) (viewHeight * interpolatedTime);
                    view.requestLayout();
                }
            }
        };
        animation.setDuration(300);
        animation.setInterpolator(new FastOutLinearInInterpolator());
        view.startAnimation(animation);
    }
}

代碼中調用方式：

AnimUtils.collapse(rv_note_drawer_list)
AnimUtils.expand(rv_note_drawer_list)