ios – 如何更改UINavigationBar底部边框的颜色？

UINavigationBar.appearance().barTintColor = UIColor.whiteColor()
UINavigationBar.appearance().shadowImage = UIImage(named: "border.jpg") //in my AppDelegate,for global appearance

SWIFT 2.x：

出于方便,我扩展了UIImage()以允许我基本上将它用作下面代码的颜色.

extension UIImage {
    class func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRectMake(0,1.0,0.5)
        UIGraphicsBeginImageContextWithOptions(rect.size,false,0)
        color.setFill()
        UIRectFill(rect)
        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

接下来,您需要在代码中添加以下行,以调整viewController的UINavigationBar的阴影图像或此实例中的颜色.

// Sets Bar's BACkground Image (Color) //
self.navigationController?.navigationBar.setBACkgroundImage(UIImage.imageWithColor(UIColor.blueColor()),forBarMetrics: .Default)
// Sets Bar's Shadow Image (Color) //
self.navigationController?.navigationBar.shadowImage = UIImage.imageWithColor(UIColor.redColor())

SWIFT 3.x / 4.x：

扩展代码：

extension UIImage {
    class func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRect(x: 0.0,y: 0.0,width: 1.0,height: 0.5)
        UIGraphicsBeginImageContextWithOptions(rect.size,0.0)
        color.setFill()
        UIRectFill(rect)
        let image : UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return image
    }
}

NavigationBar代码：

// Sets Bar's BACkground Image (Color) //
navigationController?.navigationBar.setBACkgroundImage(UIImage.imageWithColor(color: .bluE),for: .default)
// Sets Bar's Shadow Image (Color) //
navigationController?.navigationBar.shadowImage = UIImage.imageWithColor(color: .red)

编辑1：

更新了扩展代码,因此您可以调整rect大小而不更改UIImage颜色不透明度.

编辑2：

添加了Swift 3 Swift 4代码.