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
Evan Mulawski提供的答案将会非常有效。问题是你必须将视图的背景色设置为clearColor,并将masksToBounds属性设置为NO。
你可以为视图设置任何你想要的颜色
v.layer.backgroundColor = your color;
希望这能有所帮助。
如果你不想像David c建议的那样改变你的nibs和视图层次结构,这个方法可以帮你。为你的UIImageView添加圆角和阴影只需使用这个方法,例如:
[Utils roundCornersForImageView:myImageView withCornerRadius:6.0
andShadowOffset:2.0];
(!)出于性能原因,我不认为在像UITableView这样的东西中使用这段代码是个好主意,因为这段代码改变了视图层次结构。所以我会建议改变你的nib,并添加一个容器视图的阴影效果和使用戴维C.代码。
+ (void)roundCornersForImageView:(UIImageView *)imageView
withCornerRadius:(float)cornerRadius andShadowOffset:(float)shadowOffset
{
const float CORNER_RADIUS = cornerRadius;
const float BORDER_WIDTH = 1.0;
const float SHADOW_OFFSET = shadowOffset;
const float SHADOW_OPACITY = 0.8;
const float SHADOW_RADIUS = 3.0;
//Our old image now is just background image view with shadow
UIImageView *backgroundImageView = imageView;
UIView *superView = backgroundImageView.superview;
//Make wider actual visible rect taking into account shadow
//offset
CGRect oldBackgroundFrame = backgroundImageView.frame;
CGRect newBackgroundFrame = CGRectMake(oldBackgroundFrame.origin.x, oldBackgroundFrame.origin.y, oldBackgroundFrame.size.width + SHADOW_OFFSET, oldBackgroundFrame.size.height + SHADOW_OFFSET);
[backgroundImageView removeFromSuperview];
backgroundImageView.frame = newBackgroundFrame;
//Make new UIImageView with rounded corners and put our old image
CGRect frameForRoundedImageView = CGRectMake(0, 0, oldBackgroundFrame.size.width, oldBackgroundFrame.size.height);
UIImageView *roundedImageView = [[UIImageView alloc]initWithFrame:frameForRoundedImageView];
roundedImageView.image = imageView.image;
[roundedImageView.layer setCornerRadius:CORNER_RADIUS];
[roundedImageView.layer setBorderColor:[UIColor lightGrayColor].CGColor];
[roundedImageView.layer setBorderWidth:BORDER_WIDTH];
[roundedImageView.layer setMasksToBounds:YES];
//Set shadow preferences
[backgroundImageView setImage:nil];
[backgroundImageView.layer setShadowColor:[UIColor blackColor].CGColor];
[backgroundImageView.layer setShadowOpacity:SHADOW_OPACITY];
[backgroundImageView.layer setShadowRadius:SHADOW_RADIUS];
[backgroundImageView.layer setShadowOffset:CGSizeMake(SHADOW_OFFSET, SHADOW_OFFSET)];
//Add out two image views back to the view hierarchy.
[backgroundImageView addSubview:roundedImageView];
[superView addSubview:backgroundImageView];
}
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。
创建UIView的子类
class ShadowView: UIView {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
// corner radius
self.layer.cornerRadius = 10
// border
self.layer.borderWidth = 1.0
self.layer.borderColor = UIColor.black.cgColor
// shadow
self.layer.shadowColor = UIColor.black.cgColor
self.layer.shadowOffset = CGSize(width: 3, height: 3)
self.layer.shadowOpacity = 0.7
self.layer.shadowRadius = 4.0
}
}
使用. .