初始化 ActionBar 图标 并跟随 ListView 来缩放和移动图标

main.java

private ImageView getActionBarIconView() {
    return (ImageView) findViewById(android.R.id.home);
}

ActionBar actionBar = getActionBar();
actionBar.setIcon(R.drawable.ic_transparent);

mListView.setOnScrollListener(new AbsListView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
        }

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
            float ratio = clamp(mHeader.getTranslationY() / mMinHeaderTranslation, 0.0f, 1.0f);
            //move & scale

            interpolation = mAccelerateDecelerateInterpolator.getInterpolation(ratio);

            View actionBarIconView = getActionBarIconView();

            getOnScreenRect(mRect1, mHeaderLogo);
            getOnScreenRect(mRect2, actionBarIconView);

            float scaleX = 1.0F + interpolation  (mRect2.width() / mRect1.width() – 1.0F);
            float scaleY = 1.0F + interpolation  (mRect2.height() / mRect1.height() – 1.0F);
            float translationX = 0.5F  (interpolation  (mRect2.left + mRect2.right – mRect1.left – mRect1.right));
            float translationY = 0.5F  (interpolation  (mRect2.top + mRect2.bottom – mRect1.top – mRect1.bottom));

            mHeaderLogo.setTranslationX(translationX);
            mHeaderLogo.setTranslationY(translationY – mHeader.getTranslationY());
            mHeaderLogo.setScaleX(scaleX);
            mHeaderLogo.setScaleY(scaleY);
        }
    });