get the height of actionBar

ActionBarHeight

private int getActionBarHeight() {
        int actionBarHeight = getSupportActionBar().getHeight();
        if (actionBarHeight != 0) {
            return actionBarHeight;
        }

        final TypedValue typedValue = new TypedValue();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            if (getTheme().resolveAttribute(android.R.attr.actionBarSize, typedValue, true)) {
                actionBarHeight = TypedValue.complexToDimensionPixelSize(
                        typedValue.data, getResources().getDisplayMetrics());
            }
        } else {
            // 使用android.support.v7.appcompat包做actionbar兼容的情况
            if (getTheme().resolveAttribute(
                    android.support.v7.appcompat.R.attr.actionBarSize,
                    typedValue, true)) {
                actionBarHeight = TypedValue.complexToDimensionPixelSize(
                        typedValue.data, getResources().getDisplayMetrics());
            }

        }

        return actionBarHeight;
    }