用UIBezierPath给view添加阴影

        bgForListView.layer.shadowOffset = CGSizeZero;

        bgForListView.layer.shadowRadius = 10.0f;

        bgForListView.layer.shadowOpacity = 1.0f;

        bgForListView.layer.shadowPath = [UIBezierPath bezierPathWithRect:bgForListView.bounds].CGPath;