IOS:如何在4面(顶部,右侧,底部和左侧)为UIView制作阴影

Question

我正在使用下面的代码为我的阴影 ImageView

UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:self.avatarImageView.bounds];
self.avatarImageView.layer.masksToBounds = NO;
self.avatarImageView.layer.shadowColor = [UIColor blackColor].CGColor;
self.avatarImageView.layer.shadowOffset = CGSizeMake(5.0f, 5.0f);
self.avatarImageView.layer.shadowOpacity = 0.8f;
self.avatarImageView.layer.shadowPath = shadowPath.CGPath;

它会像这个图像一样在右下方留下一个阴影.

现在我想让我的ImageView左上角也有一个阴影.我应该在代码中更改什么？是否可以使视图在顶部,右侧,底部,左侧由配置仅包含阴影,或者我需要为阴影创建其他布局视图？任何帮助将非常感谢.

这就是我想要实现的目标

更新
感谢@Dipen Panchasara提供简单的解决方案.关注@Dipen Panchasara(阴影颜色为黑色)我将拥有这样的阴影图像

Answer 1

只有以下代码才能满足您的要求,您无需UIBezierPath为阴影路径创建.

// *** Set masks bounds to NO to display shadow visible ***
self.avatarImageView.layer.masksToBounds = NO;
// *** Set light gray color as shown in sample ***
self.avatarImageView.layer.shadowColor = [UIColor lightGrayColor].CGColor;
// *** *** Use following to add Shadow top, left ***
self.avatarImageView.layer.shadowOffset = CGSizeMake(-5.0f, -5.0f);

// *** Use following to add Shadow bottom, right ***
//self.avatarImageView.layer.shadowOffset = CGSizeMake(5.0f, 5.0f);

// *** Use following to add Shadow top, left, bottom, right ***
// avatarImageView.layer.shadowOffset = CGSizeZero;
// avatarImageView.layer.shadowRadius = 5.0f;

// *** Set shadowOpacity to full (1) ***
self.avatarImageView.layer.shadowOpacity = 1.0f;

Answer 2

像这样:

float shadowSize = 10.0f;
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:CGRectMake(self.avatarImageView.frame.origin.x - shadowSize / 2,
                                                                       self.avatarImageView.frame.origin.y - shadowSize / 2,
                                                                       self.avatarImageView.frame.size.width + shadowSize,
                                                                       self.avatarImageView.frame.size.height + shadowSize)];
self.avatarImageView.layer.masksToBounds = NO;
self.avatarImageView.layer.shadowColor = [UIColor blackColor].CGColor;
self.avatarImageView.layer.shadowOffset = CGSizeMake(0.0f, 0.0f);
self.avatarImageView.layer.shadowOpacity = 0.8f;
self.avatarImageView.layer.shadowPath = shadowPath.CGPath;

Swift 3版本:

    let shadowSize : CGFloat = 5.0
    let shadowPath = UIBezierPath(rect: CGRect(x: -shadowSize / 2,
                                               y: -shadowSize / 2,
                                               width: self.avatarImageView.frame.size.width + shadowSize,
                                               height: self.avatarImageView.frame.size.height + shadowSize))
    self.avatarImageView.layer.masksToBounds = false
    self.avatarImageView.layer.shadowColor = UIColor.black.cgColor
    self.avatarImageView.layer.shadowOffset = CGSize(width: 0.0, height: 0.0)
    self.avatarImageView.layer.shadowOpacity = 0.5
    self.avatarImageView.layer.shadowPath = shadowPath.cgPath

Answer 3

不使用 UIBezierPath，CGSize.zero 是这里的关键

yourView.layer.masksToBounds = false
yourView?.layer.shadowColor = UIColor.red.cgColor
yourView?.layer.shadowOffset =  CGSize.zero
yourView?.layer.shadowOpacity = 0.5
yourView?.layer.shadowRadius = 4