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;