Question 66570 in IOS Swift Question posted in
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UIView shadow not working with custom extension – Ios swift

I am trying to add a shadow to my UIViews using a custom extension that I created for the UIView class. Here is the code for the extension:

extension UIView {
    func round(_ radius : CGFloat = 10) {
        layer.cornerRadius = radius
        clipsToBounds = true
    }

    func addBorder(color: UIColor, width: CGFloat) {
        layer.borderColor = color.cgColor
        layer.borderWidth = width
    }

    func addShadow(opacity: Float, size: Double, radius: Double, color: UIColor ) {
        layer.shadowColor = color.cgColor
        layer.shadowOpacity = opacity
        layer.shadowOffset = CGSize(width: size, height: size)
        layer.shadowRadius = radius
        layer.masksToBounds = true
    }
}

The round and addBorder functions work perfectly fine, but the addShadow function does not seem to be working. I have tried calling the function on a UIView instance like this:

let myView = UIView()
myView.addShadow(opacity: 0.5, size: 2, radius: 4, color: .black)

But the shadow does not show up on the view

I have tested this extension with other types of views, such as buttons and labels, and the shadow works perfectly fine. It seems to be a problem only with UIViews.

Does anyone know what might be causing this issue? Any help would be greatly appreciated. Thank you in advance

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6

Answers


  1. 0

    The issue may be caused by the layer.masksToBounds = true line in the addShadow function. This property clips the sublayers of the layer to the layer’s bounds, which could be preventing the shadow from being displayed.

    You can try setting masksToBounds to false before adding the shadow to the layer.

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  2. 0

    yasir I have the same difficulty with shadows. I have solved it with this extension. Try it.

    extension UIView {
    /// show drop shadow under view
    /// - Parameter scale: bool variable to enable scaling
    func dropShadow(scale: Bool = true) {
        layer.masksToBounds = false
        layer.shadowColor = UIColor.gray.cgColor
        layer.shadowOpacity = 0.2
        layer.shadowOffset = CGSize.zero
        layer.shadowRadius = 10
        layer.shouldRasterize = true
        layer.rasterizationScale = scale ? UIScreen.main.scale : 1

    }
}
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  3. 0

    You can try by adding an UIBezierPath and by setting shouldRasterize = true.

    layer.shadowPath = UIBezierPath(rect: yourView.bounds).cgPath
layer.shouldRasterize = true
layer.rasterizationScale = UIScreen.main.scale
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  4. 0

    layer.masksToBounds should be false to disables the layer’s mask to display the shadow outside of the view’s bounds.

    layer.masksToBounds = false
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  5. 0

    By setting layer.masksToBounds = true, you are telling the view’s layer to clip any content that goes beyond its bounds, which would include the shadow you are trying to add.

    func addShadow(opacity: Float, size: Double, radius: Double, color: UIColor ) {
layer.shadowColor = color.cgColor
layer.shadowOpacity = opacity
layer.shadowOffset = CGSize(width: size, height: size)
layer.shadowRadius = radius }
// remove this line: layer.masksToBounds = true

    If that doesn’t work, you might want to try changing the backgroundColor attribute of the view to a color that isn’t translucent. If there is no content to render, the shadow won’t be seen since shadows are produced by displaying the content of the layer.

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  6. 0

    If we use clipsToBounds = true it will clip the frame and the shadow was cut off
    just replace the line with clipsToBounds = false will fix it.
    here is the modified code

    extension UIView {
    extension UIView {
        func round(_ radious: CGFloat = 10) {
            layer.cornerRadius = radious
            clipsToBounds = false
        }

        func addBorder(color: UIColor, width: CGFloat) {
            layer.borderColor = color.cgColor
            layer.borderWidth = width
        }

        func addShadow(opecity: Float, size: Double, radius: Double, color: UIColor ) {
            layer.shadowColor = color.cgColor
            layer.shadowOpacity = opecity
            layer.shadowOffset = CGSize(width: size, height: size)
            layer.shadowRadius = radius
            layer.masksToBounds = true
        }
    }
}
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