iOS - 在UITabBar上方获得所需的阴影

Question

我试图让我的标签栏阴影看起来像在这张图片中看到的那样：

这样做的最佳方式是什么？我正在使用objective-c
感谢

Answer 1

您可以使用以下代码为任何UI对象提供阴影

tabControl.layer.shadowOffset = CGSizeMake(0, 0);
tabControl.layer.shadowRadius = 2;
tabControl.layer.shadowColor = [UIColor blackColor].CGColor;
tabControl.layer.shadowOpacity = 0.3;

这里我举了tabControl对象的例子。

Answer 2

对于Swift 4：

self.tabBarController?.tabBar.layer.shadowColor = UIColor.black.cgColor
self.tabBarController?.tabBar.layer.shadowOffset = CGSize(width: 0.0, height: 1.0)
self.tabBarController?.tabBar.layer.shadowRadius = 5
self.tabBarController?.tabBar.layer.shadowOpacity = 1
self.tabBarController?.tabBar.layer.masksToBounds = false

Answer 3

斯威夫特4：

{{1}}

Answer 4

我更喜欢使用专用标签栏方法。

// Set `backgroundImage` to be able to use `shadowImage`
tabBar.backgroundImage = UIImage.imageWithColor(.white)
tabBar.shadowImage = #imageLiteral(resourceName: "tab_bar_shadow") // 2x34pt works for me

Answer 5

  

快捷键4：

使用此扩展程序

extension UIImage {
class func colorForNavBar(color: UIColor) -> UIImage {
    //let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)

    let rect = CGRect(origin: CGPoint(x: 0,y :0), size: CGSize(width: 1.0, height: 1.0))

    UIGraphicsBeginImageContext(rect.size)
    let context = UIGraphicsGetCurrentContext()

    context!.setFillColor(color.cgColor)
    context!.fill(rect)

    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()


     return image!
    } 
}

使用RGB设置阴影颜色

//Set BackgroundColor
 UITabBar.appearance().backgroundImage = UIImage.colorForNavBar(color: .white)

//Set Shadow Color
 UITabBar.appearance().shadowImage = UIImage.colorForNavBar(color: UIColor.init(red: 120/255.0, green: 120/255.0, blue: 120/255.0, alpha: 1.0))

Answer 6

试试这个

 [[UITabBar appearance] setShadowImage:[UIImage imageNamed:@"transparentShadow.png"]];