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
我尝试了这篇文章中的很多解决方案，最终得到了下面的解决方案。这是完全证明解决方案，除非你需要在一个清晰的颜色视图下滴阴影。
- (void)addShadowWithRadius:(CGFloat)shadowRadius withOpacity:(CGFloat)shadowOpacity withOffset:(CGSize)shadowOffset withColor:(UIColor *)shadowColor withCornerradius:(CGFloat)cornerRadius
{
UIView *viewShadow = [[UIView alloc]initWithFrame:self.frame];
viewShadow.backgroundColor = [UIColor whiteColor];
viewShadow.layer.shadowColor = shadowColor.CGColor;
viewShadow.layer.shadowOffset = shadowOffset;
viewShadow.layer.shadowRadius = shadowRadius;
viewShadow.layer.shadowOpacity = shadowOpacity;
viewShadow.layer.cornerRadius = cornerRadius;
viewShadow.layer.masksToBounds = NO;
[self.superview insertSubview:viewShadow belowSubview:self];
[viewShadow setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeWidth multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeHeight multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:viewShadow attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:viewShadow attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0]];
[self layoutIfNeeded];
self.layer.cornerRadius = cornerRadius;
self.layer.masksToBounds = YES;
}
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。
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!
我尝试了这篇文章中的很多解决方案，最终得到了下面的解决方案。这是完全证明解决方案，除非你需要在一个清晰的颜色视图下滴阴影。
- (void)addShadowWithRadius:(CGFloat)shadowRadius withOpacity:(CGFloat)shadowOpacity withOffset:(CGSize)shadowOffset withColor:(UIColor *)shadowColor withCornerradius:(CGFloat)cornerRadius
{
UIView *viewShadow = [[UIView alloc]initWithFrame:self.frame];
viewShadow.backgroundColor = [UIColor whiteColor];
viewShadow.layer.shadowColor = shadowColor.CGColor;
viewShadow.layer.shadowOffset = shadowOffset;
viewShadow.layer.shadowRadius = shadowRadius;
viewShadow.layer.shadowOpacity = shadowOpacity;
viewShadow.layer.cornerRadius = cornerRadius;
viewShadow.layer.masksToBounds = NO;
[self.superview insertSubview:viewShadow belowSubview:self];
[viewShadow setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeWidth multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeHeight multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:viewShadow attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];
[self.superview addConstraint:[NSLayoutConstraint constraintWithItem:viewShadow attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:viewShadow attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0]];
[self layoutIfNeeded];
self.layer.cornerRadius = cornerRadius;
self.layer.masksToBounds = YES;
}
Swift 4解决方案，使UICollectionViewCell圆形和添加阴影，没有任何扩展和并发症:)
注意:对于简单的视图，例如按钮。请看这篇文章中的@suragch的回答。 https://stackoverflow.com/a/34984063/7698092。按钮测试成功
以防有人还在努力使角落圆润，同时添加阴影。虽然这个解决方案适用于UICollectionViewCell，但它可以推广到任何视图。
这个技巧对我来说很有效，不需要做任何扩展和所有复杂的事情。我正在使用storyBoard。
技术
你必须在storyBoard的UICollectionViewCell中添加一个UIView(让我们说它是“containerView”)，并在这个containerView中添加所有必需的视图(按钮，图像等)。 见截图。
连接containerView的出口。在CellforItemAtIndexPath委托函数中添加以下代码行。
//adds shadow to the layer of cell
cell.layer.cornerRadius = 3.0
cell.layer.masksToBounds = false
cell.layer.shadowColor = UIColor.black.cgColor
cell.layer.shadowOffset = CGSize(width: 0, height: 0)
cell.layer.shadowOpacity = 0.6
//makes the cell round
let containerView = cell.containerView!
containerView.layer.cornerRadius = 8
containerView.clipsToBounds = true
输出
查看模拟器截图
这里有一个肯定有效的解决方案!
我已经创建了UIView扩展所需的边应用阴影如下
enum AIEdge:Int {
case
Top,
Left,
Bottom,
Right,
Top_Left,
Top_Right,
Bottom_Left,
Bottom_Right,
All,
None
}
extension UIView {
func applyShadowWithCornerRadius(color:UIColor, opacity:Float, radius: CGFloat, edge:AIEdge, shadowSpace:CGFloat, cornerRadius: CGFloat) {
var sizeOffset:CGSize = CGSize.zero
switch edge {
case .Top:
sizeOffset = CGSize(width: 0, height: -shadowSpace)
case .Left:
sizeOffset = CGSize(width: -shadowSpace, height: 0)
case .Bottom:
sizeOffset = CGSize(width: 0, height: shadowSpace)
case .Right:
sizeOffset = CGSize(width: shadowSpace, height: 0)
case .Top_Left:
sizeOffset = CGSize(width: -shadowSpace, height: -shadowSpace)
case .Top_Right:
sizeOffset = CGSize(width: shadowSpace, height: -shadowSpace)
case .Bottom_Left:
sizeOffset = CGSize(width: -shadowSpace, height: shadowSpace)
case .Bottom_Right:
sizeOffset = CGSize(width: shadowSpace, height: shadowSpace)
case .All:
sizeOffset = CGSize(width: 0, height: 0)
case .None:
sizeOffset = CGSize.zero
}
self.layer.cornerRadius = cornerRadius
self.layer.masksToBounds = true
self.layer.shadowColor = color.cgColor
self.layer.shadowOpacity = opacity
self.layer.shadowOffset = sizeOffset
self.layer.shadowRadius = radius
self.layer.masksToBounds = false
self.layer.shadowPath = UIBezierPath(roundedRect:self.bounds, cornerRadius:self.layer.cornerRadius).cgPath
}
}
最后，你可以为你的UIView子类调用下面的阴影函数，你也可以指定边缘上应用阴影，尝试不同的变化根据你需要改变下面方法调用的参数。
viewRoundedToBeShadowedAsWell.applyShadowWithCornerRadius(color: .gray, opacity: 1, radius: 15, edge: AIEdge.All, shadowSpace: 15)
注意:如果仍然不工作，试着从主线程调用它
DispatchQueue.main.async {
viewRoundedToBeShadowedAsWell.applyShadowWithCornerRadius(color: .gray, opacity: 1, radius: 15, edge: AIEdge.All, shadowSpace: 15)
}
希望有人觉得这有用!
以下是结果图片:
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