Effectively render a Drop Shadow on a UIView subclass

Adding a drop shadow to your UIView subclass is as easy as the following code.

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UIView *customView = [[UIView alloc] init]; ... customView.layer.shadowColor    = [[UIColor lightGrayColor] CGColor]; customView.layer.shadowOffset   = CGSizeMake(1, 1); customView.layer.shadowOpacity  = 1.0; customView.layer.shadowRadius   = 2.0; ...

While the common use case of such trick is on rendering stationary views, and no doubt it works perfectly that way, placing them inside a scrollable view like UISrollView or UITableView yields a different feel - it lags a bit when scrolling. So the way to solve this issue and keep them scrolling smoothly is to make use of UIBezierPath. You create an instance of this based on the `bounds` of the receiving view. Then set it as the `shadowPath` of the view's layer object.

1 2	UIBezierPath *path  = [UIBezierPath bezierPathWithRect:customView.bounds]; customView.layer.shadowPath = [path CGPath];

Now let's modify our base code to include the bezier path.

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UIView *customView = [[UIView alloc] init]; ... UIBezierPath *path  = [UIBezierPath bezierPathWithRect:customView.bounds]; customView.layer.shadowPath = [path CGPath];   customView.layer.shadowColor    = [[UIColor lightGrayColor] CGColor]; customView.layer.shadowOffset   = CGSizeMake(1, 1); customView.layer.shadowOpacity  = 1.0; customView.layer.shadowRadius   = 2.0; ...