如何为UIButton添加投影？

我想向UIButton添加阴影。我尝试使用self.layer.shadow *属性。这些属性在UIView中工作，但在UIButton中的行为有所不同。如果能得到任何指示画阴影的指针，我将不胜感激。谢谢！

self.layer.cornerRadius = 8.0f;
self.layer.masksToBounds = YES;
self.layer.borderWidth = 1.0f;

self.layer.shadowColor = [UIColor greenColor].CGColor;
self.layer.shadowOpacity = 0.8;
self.layer.shadowRadius = 12;
self.layer.shadowOffset = CGSizeMake(12.0f, 12.0f);

在这个问题中只有一个微小的错误会导致阴影不显示：masksToBounds:YES还会掩盖阴影！这是正确的代码：

self.layer.cornerRadius = 8.0f;
self.layer.masksToBounds = NO;
self.layer.borderWidth = 1.0f;

self.layer.shadowColor = [UIColor greenColor].CGColor;
self.layer.shadowOpacity = 0.8;
self.layer.shadowRadius = 12;
self.layer.shadowOffset = CGSizeMake(12.0f, 12.0f);

不幸的是，这意味着我们不能在没有技巧的情况下同时掩盖内容和阴影。

记住要#import <QuartzCore/QuartzCore.h>。

如果您正在使用，这是一个简单的解决方案UIButton：

#import <QuartzCore/QuartzCore.h>

button.imageView.layer.cornerRadius = 7.0f;
button.layer.shadowRadius = 3.0f;
button.layer.shadowColor = [UIColor blackColor].CGColor;
button.layer.shadowOffset = CGSizeMake(0.0f, 1.0f);
button.layer.shadowOpacity = 0.5f;
button.layer.masksToBounds = NO;

刚开始工作，就认为值得发布。希望对您有所帮助！

这是一个子类，它不仅创建阴影，而且在您按下按钮时会使其动画。

//
//  ShadowButton.h

#import <Foundation/Foundation.h>

@interface ShadowButton : UIButton {
}

@end

//
//  ShadowButton.m

#import "ShadowButton.h"
#import <QuartzCore/QuartzCore.h>

@implementation ShadowButton

-(void)setupView{

    self.layer.shadowColor = [UIColor blackColor].CGColor;
    self.layer.shadowOpacity = 0.5;
    self.layer.shadowRadius = 1;
    self.layer.shadowOffset = CGSizeMake(2.0f, 2.0f);

}

-(id)initWithFrame:(CGRect)frame{
    if((self = [super initWithFrame:frame])){
        [self setupView];
    }

    return self;
}

-(id)initWithCoder:(NSCoder *)aDecoder{
    if((self = [super initWithCoder:aDecoder])){
        [self setupView];
    }

    return self;
}

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    self.contentEdgeInsets = UIEdgeInsetsMake(1.0,1.0,-1.0,-1.0);
    self.layer.shadowOffset = CGSizeMake(1.0f, 1.0f);
    self.layer.shadowOpacity = 0.8;

    [super touchesBegan:touches withEvent:event];

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
    self.contentEdgeInsets = UIEdgeInsetsMake(0.0,0.0,0.0,0.0);
    self.layer.shadowOffset = CGSizeMake(2.0f, 2.0f);
    self.layer.shadowOpacity = 0.5;

    [super touchesEnded:touches withEvent:event];

}

@end

您可以创建一个子类并在Xcode中配置其值

下面是一个示例：

import UIKit
import QuartzCore

@IBDesignable
class CustomButton: UIButton {

@IBInspectable var cornerRadius: CGFloat = 0 {
    didSet {
        layer.cornerRadius = cornerRadius
    }
}

@IBInspectable var borderWidth: CGFloat = 0 {
    didSet {
        layer.borderWidth = borderWidth
    }
}

@IBInspectable var borderColor: UIColor = UIColor.gray {
    didSet {
        layer.borderColor = borderColor.cgColor
    }
}

@IBInspectable var shadowColor: UIColor = UIColor.gray {
    didSet {
        layer.shadowColor = shadowColor.cgColor
    }
}

@IBInspectable var shadowOpacity: Float = 1.0 {
    didSet {
        layer.shadowOpacity = shadowOpacity
    }
}

@IBInspectable var shadowRadius: CGFloat = 1.0 {
    didSet {
        layer.shadowRadius = shadowRadius
    }
}

@IBInspectable var masksToBounds: Bool = true {
    didSet {
        layer.masksToBounds = masksToBounds
    }
}

@IBInspectable var shadowOffset: CGSize = CGSize(width: 12, height: 12) {
    didSet {
        layer.shadowOffset = shadowOffset
    }
}


 }

您可以继承UIButton并覆盖drawRect：方法，并手动添加阴影。要做的工作还很多，您现在应该了解有关石英2d的一些知识，但是结果正是您想要的。否则，您可以只添加一个图像，但是我更喜欢将UIButton子类化，因为它在按钮大小方面非常灵活，更通用。