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

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)
        }

    }
}

其他回答

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:

下面的方法最适合我 (这段代码位于UIView扩展中,因此self表示一些我们必须添加阴影和圆角的UIView)

- (void)addShadowViewWithCornerRadius:(CGFloat)radius {

UIView *container = self.superview;

if (!container) {
    return;
}

UIView *shadowView = [[UIView alloc] init];
shadowView.translatesAutoresizingMaskIntoConstraints = NO;
shadowView.backgroundColor = [UIColor lightGrayColor];
shadowView.layer.cornerRadius = radius;
shadowView.layer.masksToBounds = YES;

[container addSubview:shadowView];
[container bringSubviewToFront:shadowView];

[container addConstraint:[NSLayoutConstraint constraintWithItem:shadowView
                                                      attribute:NSLayoutAttributeWidth
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self
                                                      attribute:NSLayoutAttributeWidth
                                                     multiplier:1.0
                                                       constant:0.0]];
[container addConstraint:[NSLayoutConstraint constraintWithItem:shadowView
                                                      attribute:NSLayoutAttributeLeading
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self
                                                      attribute:NSLayoutAttributeLeading
                                                     multiplier:1.0
                                                       constant:2.0]];

[container addConstraint:[NSLayoutConstraint constraintWithItem:shadowView
                                                      attribute:NSLayoutAttributeHeight
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self
                                                      attribute:NSLayoutAttributeHeight
                                                     multiplier:1.0
                                                       constant:0.0]];
[container addConstraint:[NSLayoutConstraint constraintWithItem:shadowView
                                                      attribute:NSLayoutAttributeTop
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self
                                                      attribute:NSLayoutAttributeTop
                                                     multiplier:1.0
                                                       constant:2.0]];
[container sendSubviewToBack:shadowView];
}

此代码与其他代码示例之间的主要区别在于,它将阴影视图添加为兄弟视图(而不是将当前视图添加为阴影视图的子视图),从而消除了以任何方式修改现有视图层次结构的需要。

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];

我在UIView中创建了一个helper

@interface UIView (Helper)

- (void)roundCornerswithRadius:(float)cornerRadius
               andShadowOffset:(float)shadowOffset;
@end

你可以这样叫它

[self.view roundCornerswithRadius:5 andShadowOffset:5];

这是实现

- (void)roundCornerswithRadius:(float)cornerRadius
               andShadowOffset:(float)shadowOffset
{
    const float CORNER_RADIUS = cornerRadius;
    const float SHADOW_OFFSET = shadowOffset;
    const float SHADOW_OPACITY = 0.5;
    const float SHADOW_RADIUS = 3.0;

    UIView *superView = self.superview;

    CGRect oldBackgroundFrame = self.frame;
    [self removeFromSuperview];

    CGRect frameForShadowView = CGRectMake(0, 0, oldBackgroundFrame.size.width, oldBackgroundFrame.size.height);
    UIView *shadowView = [[UIView alloc] initWithFrame:frameForShadowView];
    [shadowView.layer setShadowOpacity:SHADOW_OPACITY];
    [shadowView.layer setShadowRadius:SHADOW_RADIUS];
    [shadowView.layer setShadowOffset:CGSizeMake(SHADOW_OFFSET, SHADOW_OFFSET)];

    [self.layer setCornerRadius:CORNER_RADIUS];
    [self.layer setMasksToBounds:YES];

    [shadowView addSubview:self];
    [superView addSubview:shadowView];

}

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。