WheelView.java 文件源码

/**
 * Initializes resources
 */
private void initResourcesIfNecessary() {
    if (centerDrawable == null) {
        centerDrawable = getContext().getResources().getDrawable(
                R.drawable.wheel_val);
    }

    if (topShadow == null) {
        topShadow = new GradientDrawable(Orientation.TOP_BOTTOM,
                SHADOWS_COLORS);
    }

    if (bottomShadow == null) {
        bottomShadow = new GradientDrawable(Orientation.BOTTOM_TOP,
                SHADOWS_COLORS);
    }

    setBackgroundResource(R.drawable.wheel_bg);
}