android 得到根視圖 和得到根actionbar

public ViewGroup getActionBar(View view) {
    try {
        if (view instanceof ViewGroup) {
            ViewGroup viewGroup = (ViewGroup) view;

            if (viewGroup instanceof android.support.v7.widget.Toolbar) {
                return viewGroup;
            }

            for (int i = 0; i < viewGroup.getChildCount(); i++) {
                ViewGroup actionBar = getActionBar(viewGroup.getChildAt(i));

                if (actionBar != null) {
                    return actionBar;
                }
            }
        }
    } catch (Exception e) {
    }

    return null;
}

 

ViewGroup actionBar = getActionBar(getWindow().getDecorView());
actionBar.setBackgroundResource(R.color.colorAccent);

 

得到根視圖

decorView = (ViewGroup) getWindow().getDecorView().findViewById(android.R.id.content);