UIButton底影

Question

我有一个UIButton，非常类似于标准的iOS键盘字母按钮。

我不知道如何只为底层创建一个阴影，就像iOS一样。

我使用下面的代码，但是我看到了所有方面的阴影，而不仅仅是底部：

CALayer *buttonLayer = [[CALayer alloc] init];
buttonLayer.shadowColor = [UIColor grayColor].CGColor;
buttonLayer.shadowOffset = CGSizeMake(0.f,1.f);
buttonLayer.masksToBounds = NO;
buttonLayer.shadowOpacity = 1.f;

你能告诉我如何达到同样的效果吗？提前致谢。

Answer 1

您可以混合cornerRadius和shadow属性。我在iOS 8上测试过它。

Objective-C的：

[self.globeButton setImage:[UIImage imageNamed:@"Globe"] forState:UIControlStateNormal];
self.globeButton.backgroundColor = [UIColor colorWithRed:171 green:178 blue:186 alpha:1.0f];
// Shadow and Radius
self.globeButton.layer.shadowColor = [[UIColor colorWithRed:0 green:0 blue:0 alpha:0.25f] CGColor];
self.globeButton.layer.shadowOffset = CGSizeMake(0, 2.0f);
self.globeButton.layer.shadowOpacity = 1.0f;
self.globeButton.layer.shadowRadius = 0.0f;
self.globeButton.layer.masksToBounds = NO;
self.globeButton.layer.cornerRadius = 4.0f;

迅速：

globeButton.setImage(UIImage(named: "Globe"), forState: .Normal)
globeButton.backgroundColor = UIColor(red: 171/255, green: 178/255, blue: 186/255, alpha: 1.0)
// Shadow and Radius
globeButton.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).CGColor
globeButton.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
globeButton.layer.shadowOpacity = 1.0
globeButton.layer.shadowRadius = 0.0
globeButton.layer.masksToBounds = false
globeButton.layer.cornerRadius = 4.0

结果：

Answer 2

SWIFT 3

import UIKit

class ButtonWithShadow: UIButton {

    override func draw(_ rect: CGRect) {
        updateLayerProperties()
    }

    func updateLayerProperties() {
        self.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
        self.layer.shadowOffset = CGSize(width: 0, height: 3)
        self.layer.shadowOpacity = 1.0
        self.layer.shadowRadius = 10.0
        self.layer.masksToBounds = false
    }

}

！仅当您不需要角半径和阴影同时。否则请观看this。

Answer 3

一定要将shadowRadius设置为0：

给定一个名为UIButton的button属性设置其背衬层属性，如下所示：

self.button.layer.shadowColor = [UIColor grayColor].CGColor;
self.button.layer.shadowOffset = CGSizeMake(0, 1.0);
self.button.layer.shadowOpacity = 1.0;
self.button.layer.shadowRadius = 0.0;

Answer 4

您可以尝试使用此代码:(抱歉，我只知道快速，而不是obj c。此代码将在您的按钮上添加底部阴影。

button.layer.masksToBounds = false
button.layer.shadowColor = UIColor(rgb: 0x000000, alpha: 1.0).CGColor
button.layer.shadowOpacity = 1.0
button.layer.shadowRadius = 0
button.layer.shadowOffset = CGSizeMake(0, 1.0)

Answer 5

在swift 2.0中，在类声明之前或swift文件函数中添加阴影uiview（uibutton）代码：

extension UIView {

    func addShadowView(width:CGFloat=0.2, height:CGFloat=0.2, Opacidade:Float=0.7, maskToBounds:Bool=false, radius:CGFloat=0.5){
         self.layer.shadowColor = UIColor.blackColor().CGColor
         self.layer.shadowOffset = CGSize(width: width, height: height)
         self.layer.shadowRadius = radius
         self.layer.shadowOpacity = Opacidade
         self.layer.masksToBounds = maskToBounds
    }

}

在viewdidload中添加此代码

button.addShadowView()

Answer 6

CornerRadius和阴影在同一层上混合不好。所以你必须在UIView中嵌入你的“被逼迫”的UIButton。阴影将应用于此UIView。

以下代码作为示例，生成下面的图像：

导入UIKit

class CustomButton: UIButton {

    required init(coder decoder: NSCoder) {
        super.init(coder: decoder)

        backgroundColor = UIColor.whiteColor()
    }

    override func drawRect(rect: CGRect) {
        updateLayerProperties()
    }

    func updateLayerProperties() {
        layer.masksToBounds = true
        layer.cornerRadius = 12.0

        //superview is your optional embedding UIView
        if let superview = superview {
            superview.backgroundColor = UIColor.clearColor()
            superview.layer.shadowColor = UIColor.darkGrayColor().CGColor
            superview.layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: 12.0).CGPath
            superview.layer.shadowOffset = CGSize(width: 2.0, height: 2.0)
            superview.layer.shadowOpacity = 1.0
            superview.layer.shadowRadius = 2
            superview.layer.masksToBounds = true
            superview.clipsToBounds = false
        }
    }

}

Answer 7

将此方法放入UIView扩展中并使用偏移值

func drawShadow(shadowColor: UIColor = UIColor.black, opacity: Float =
0.3, offset: CGSize, radius: CGFloat = 5, shouldRasterize : Bool = false) {
        self.layer.shadowColor = shadowColor.cgColor
        self.layer.shadowOpacity = opacity
        self.layer.shadowOffset = offset
        self.layer.shadowRadius = radius
        self.layer.shouldRasterize = shouldRasterize
    }

Answer 8

查看底部阴影swift 4.2

viewTop.layer.shadowOffset = CGSize(width: 0, height: 1)
viewTop.layer.shadowColor = UIColor.lightGray.cgColor
viewTop.layer.shadowOpacity = 1
viewTop.layer.shadowRadius = 5
viewTop.layer.masksToBounds = false

Answer 9

我创建了IBInspectable扩展，可以帮助你。

你可以直接从storyboard分配

斯威夫特5

//MARK:- IBInspectable
extension UIView {
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(cgColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }

    @IBInspectable
    var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.masksToBounds = false
            layer.shadowRadius = newValue
        }
    }

    @IBInspectable
    var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.masksToBounds = false
            layer.shadowOpacity = newValue
        }
    }

    @IBInspectable
    var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            layer.masksToBounds = false
            layer.shadowOffset = newValue
        }
    }

    @IBInspectable
    var shadowColor: UIColor? {
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.shadowColor = color.cgColor
            } else {
                layer.shadowColor = nil
            }
        }
    }
}