我在一个应用程序上工作了几年,收到了一个简单的设计请求:在UIView上圆角并添加投影。做以下所给的事
我想要一个自定义的UIView…:我只是想要一个空白的白色视图与圆角和光滴阴影(没有照明效果)。我可以逐个执行这些操作,但通常会发生clipToBounds/maskToBounds冲突。
我在一个应用程序上工作了几年,收到了一个简单的设计请求:在UIView上圆角并添加投影。做以下所给的事
我想要一个自定义的UIView…:我只是想要一个空白的白色视图与圆角和光滴阴影(没有照明效果)。我可以逐个执行这些操作,但通常会发生clipToBounds/maskToBounds冲突。
当前回答
阴影+边界+角半径
scrollview.backgroundColor = [UIColor whiteColor];
CALayer *ScrlViewLayer = [scrollview layer];
[ScrlViewLayer setMasksToBounds:NO ];
[ScrlViewLayer setShadowColor:[[UIColor lightGrayColor] CGColor]];
[ScrlViewLayer setShadowOpacity:1.0 ];
[ScrlViewLayer setShadowRadius:6.0 ];
[ScrlViewLayer setShadowOffset:CGSizeMake( 0 , 0 )];
[ScrlViewLayer setShouldRasterize:YES];
[ScrlViewLayer setCornerRadius:5.0];
[ScrlViewLayer setBorderColor:[UIColor lightGrayColor].CGColor];
[ScrlViewLayer setBorderWidth:1.0];
[ScrlViewLayer setShadowPath:[UIBezierPath bezierPathWithRect:scrollview.bounds].CGPath];
其他回答
下面的代码片段为UIView v添加了边框、边框半径和投影:
// border radius
[v.layer setCornerRadius:30.0f];
// border
[v.layer setBorderColor:[UIColor lightGrayColor].CGColor];
[v.layer setBorderWidth:1.5f];
// drop shadow
[v.layer setShadowColor:[UIColor blackColor].CGColor];
[v.layer setShadowOpacity:0.8];
[v.layer setShadowRadius:3.0];
[v.layer setShadowOffset:CGSizeMake(2.0, 2.0)];
Swift 5版本:
// border radius
v.layer.cornerRadius = 30.0
// border
v.layer.borderColor = UIColor.lightGray.cgColor
v.layer.borderWidth = 1.5
// drop shadow
v.layer.shadowColor = UIColor.black.cgColor
v.layer.shadowOpacity = 0.8
v.layer.shadowRadius = 3.0
v.layer.shadowOffset = CGSize(width: 2.0, height: 2.0)
您可以根据需要调整设置。
此外,将QuartzCore框架添加到您的项目中,并:
#import <QuartzCore/QuartzCore.h>
请看我关于masksToBounds的其他答案。
Note
这可能并不适用于所有情况。如果您发现此方法干扰您正在执行的其他绘图操作,请参阅此答案。
extension UIView {
func dropRoundedShadowForAllSides() {
let backgroundView = UIView(frame:self.frame)
let radius = frame.height/2
backgroundView.layer.masksToBounds = false
self.layer.masksToBounds = true
backgroundView.layer.shadowOffset = CGSize(width: 0.0, height: 0.0)
backgroundView.layer.shadowRadius = 4
backgroundView.layer.shadowOpacity = 0.4
let path = UIBezierPath()
// Start at the Top Left Corner + radius distance
path.move(to: CGPoint(x: 2*radius, y: 0.0))
// Move to the Top Right Corner - radius distance
path.addLine(to: CGPoint(x: backgroundView.frame.size.width - radius, y: 0.0))
// Move to top right corner + radius down as curve
let centerPoint1 = CGPoint(x:backgroundView.frame.size.width - radius,y:radius)
path.addArc(withCenter: centerPoint1, radius: radius, startAngle: 3*(.pi/2), endAngle: 0, clockwise: true)
// Move to the Bottom Right Corner - radius
path.addLine(to: CGPoint(x: backgroundView.frame.size.width, y: backgroundView.frame.size.height - radius))
// Move to top right corner + radius left as curve
let centerPoint2 = CGPoint(x:backgroundView.frame.size.width - radius,y:backgroundView.frame.size.height - radius)
path.addArc(withCenter: centerPoint2, radius: radius, startAngle: 0, endAngle: .pi/2, clockwise: true)
// Move to the Bottom Left Corner - radius
path.addLine(to: CGPoint(x: radius, y: backgroundView.frame.size.height))
// Move to left right corner - radius up as curve
let centerPoint3 = CGPoint(x:radius,y:backgroundView.frame.size.height - radius)
path.addArc(withCenter: centerPoint3, radius: radius, startAngle: .pi/2, endAngle: .pi, clockwise: true)
// Move to the top Left Corner - radius
path.addLine(to: CGPoint(x: 0, y: radius))
// Move to top right corner + radius down as curve
let centerPoint4 = CGPoint(x:radius,y:radius)
path.addArc(withCenter: centerPoint4, radius: radius, startAngle: .pi, endAngle: 3 * (.pi/2), clockwise: true)
path.close()
backgroundView.layer.shadowPath = path.cgPath
if let superView = self.superview {
superView.addSubview(backgroundView)
superView.sendSubview(toBack: backgroundView)
superView.bringSubview(toFront: self)
}
}
}
Swift 3 & IBInspectable解决方案: 灵感来自Ade的解决方案
首先,创建一个UIView扩展:
//
// UIView-Extension.swift
//
import Foundation
import UIKit
@IBDesignable
extension UIView {
// Shadow
@IBInspectable var shadow: Bool {
get {
return layer.shadowOpacity > 0.0
}
set {
if newValue == true {
self.addShadow()
}
}
}
fileprivate func addShadow(shadowColor: CGColor = UIColor.black.cgColor, shadowOffset: CGSize = CGSize(width: 3.0, height: 3.0), shadowOpacity: Float = 0.35, shadowRadius: CGFloat = 5.0) {
let layer = self.layer
layer.masksToBounds = false
layer.shadowColor = shadowColor
layer.shadowOffset = shadowOffset
layer.shadowRadius = shadowRadius
layer.shadowOpacity = shadowOpacity
layer.shadowPath = UIBezierPath(roundedRect: layer.bounds, cornerRadius: layer.cornerRadius).cgPath
let backgroundColor = self.backgroundColor?.cgColor
self.backgroundColor = nil
layer.backgroundColor = backgroundColor
}
// Corner radius
@IBInspectable var circle: Bool {
get {
return layer.cornerRadius == self.bounds.width*0.5
}
set {
if newValue == true {
self.cornerRadius = self.bounds.width*0.5
}
}
}
@IBInspectable var cornerRadius: CGFloat {
get {
return self.layer.cornerRadius
}
set {
self.layer.cornerRadius = newValue
}
}
// Borders
// Border width
@IBInspectable
public var borderWidth: CGFloat {
set {
layer.borderWidth = newValue
}
get {
return layer.borderWidth
}
}
// Border color
@IBInspectable
public var borderColor: UIColor? {
set {
layer.borderColor = newValue?.cgColor
}
get {
if let borderColor = layer.borderColor {
return UIColor(cgColor: borderColor)
}
return nil
}
}
}
然后,在界面构建器中选择你的UIView,设置阴影ON和角半径,如下所示:
结果!
斯威夫特
// corner radius
blueView.layer.cornerRadius = 10
// border
blueView.layer.borderWidth = 1.0
blueView.layer.borderColor = UIColor.black.cgColor
// shadow
blueView.layer.shadowColor = UIColor.black.cgColor
blueView.layer.shadowOffset = CGSize(width: 3, height: 3)
blueView.layer.shadowOpacity = 0.7
blueView.layer.shadowRadius = 4.0
探索选择
问题1:阴影被剪掉了
如果我们希望将子层或子视图(如图像)的内容剪辑到视图的边界,该怎么办?
我们可以用
blueView.layer.masksToBounds = true
(另外,blueView。clipsToBounds = true给出相同的结果。)
但是,哦不!影子也被剪掉了,因为它在边界之外!怎么办呢?怎么办呢?
解决方案
阴影和边界使用单独的视图。基本视图是透明的,并且有阴影。边界视图将它拥有的任何其他子内容剪辑到它的边界。
// add the shadow to the base view
baseView.backgroundColor = UIColor.clear
baseView.layer.shadowColor = UIColor.black.cgColor
baseView.layer.shadowOffset = CGSize(width: 3, height: 3)
baseView.layer.shadowOpacity = 0.7
baseView.layer.shadowRadius = 4.0
// add the border to subview
let borderView = UIView()
borderView.frame = baseView.bounds
borderView.layer.cornerRadius = 10
borderView.layer.borderColor = UIColor.black.cgColor
borderView.layer.borderWidth = 1.0
borderView.layer.masksToBounds = true
baseView.addSubview(borderView)
// add any other subcontent that you want clipped
let otherSubContent = UIImageView()
otherSubContent.image = UIImage(named: "lion")
otherSubContent.frame = borderView.bounds
borderView.addSubview(otherSubContent)
结果如下:
问题2:表现不佳
添加圆角和阴影可以提高性能。您可以通过为阴影使用预定义的路径并指定它是栅格化来提高性能。下面的代码可以添加到上面的示例中。
baseView.layer.shadowPath = UIBezierPath(roundedRect: baseView.bounds, cornerRadius: 10).cgPath
baseView.layer.shouldRasterize = true
baseView.layer.rasterizationScale = UIScreen.main.scale
更多细节请看这篇文章。看这里和这里。
我们用Swift 4和Xcode 9测试了这个答案。
一种方法是将带有圆角的视图放到带有投影的视图中。
UIView* roundedView = [[UIView alloc] initWithFrame: frame];
roundedView.layer.cornerRadius = 5.0;
roundedView.layer.masksToBounds = YES;
UIView* shadowView = [[UIView alloc] initWithFrame: frame];
shadowView.layer.shadowColor = [UIColor blackColor].CGColor;
shadowView.layer.shadowRadius = 5.0;
shadowView.layer.shadowOffset = CGSizeMake(3.0, 3.0);
shadowView.layer.shadowOpacity = 1.0;
[shadowView addSubview: roundedView];
然后你可以在任何你想要的地方添加shadowView。