在Swift 4中使UISearch栏变得透明

Question

我试图在swift 4中使搜索栏透明。

这是我的代码

    let  searchBar = UISearchBar()
    searchBar.sizeToFit()
    searchBar.placeholder = "search
    searchBar.isTranslucent = true
    searchBar.barTintColor = UIColor.clear
    searchBar.backgroundColor = UIColor.clear
    self.tabBarController?.navigationItem.titleView = searchBar

它看起来像这样

我想在屏幕截图中实现搜索栏。 请允许任何人就此提出建议。

Answer 1

uisearchbar的所有部分完全透明：

searchBar.setSearchFieldBackgroundImage(UIImage(), for: .normal)
searchBar.setBackgroundImage(UIImage(), for: .any, barMetrics: .default)

• searchBar是StoryBoard的UISearchBar的插座

Answer 2

试试这段代码：

searchBar.setSearchFieldBackgroundImage(UIImage(), for: .normal)

或：

UITextField.appearance(whenContainedInInstancesOf: [UISearchBar.self]).backgroundColor = .clear

Answer 3

    @IBOutlet weak var searchBarView:UISearchBar!

    searchBarView.placeholder = textStr
    searchBarView.setTextColor(color: .white)
    searchBarView.layer.borderWidth = 1
    searchBarView.layer.borderColor = searchBarView.barTintColor?.cgColor //orange
    searchBarView.setTextFieldColor(color: .clear)
    searchBarView.setPlaceholderTextColor(color: .white)
    searchBarView.setSearchImageColor(color: .white)
    searchBarView.setTextFieldClearButtonColor(color: .white)


  //MARK: - UISearchBar EXTENSION
    extension UISearchBar {

        private func getViewElement<T>(type: T.Type) -> T? {

            let svs = subviews.flatMap { $0.subviews }
            guard let element = (svs.filter { $0 is T }).first as? T else { return nil }
            return element
        }

        func getSearchBarTextField() -> UITextField? {
            return getViewElement(type: UITextField.self)
        }

        func setTextColor(color: UIColor) {

            if let textField = getSearchBarTextField() {
                textField.textColor = color
            }
        }

        func setTextFieldColor(color: UIColor) {

            if let textField = getViewElement(type: UITextField.self) {
                switch searchBarStyle {
                case .minimal:
                    textField.layer.backgroundColor = color.cgColor
                    textField.layer.cornerRadius = 6
                case .prominent, .default:
                    textField.backgroundColor = color
                }
            }
        }

        func setPlaceholderTextColor(color: UIColor) {

            if let textField = getSearchBarTextField() {
                textField.attributedPlaceholder = NSAttributedString(string: self.placeholder != nil ? self.placeholder! : "", attributes: [NSForegroundColorAttributeName: color])
            }
        }

        func setTextFieldClearButtonColor(color: UIColor) {

            if let textField = getSearchBarTextField() {

                let button = textField.value(forKey: "clearButton") as! UIButton
                if let image = button.imageView?.image {
                    button.setImage(image.transform(withNewColor: color), for: .normal)
                }
            }
        }

        func setSearchImageColor(color: UIColor) {

            if let imageView = getSearchBarTextField()?.leftView as? UIImageView {
                imageView.image = imageView.image?.transform(withNewColor: color)
            }
        }
    }



extension UIImage {

    func transform(withNewColor color: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, false, scale)

        let context = UIGraphicsGetCurrentContext()!
        context.translateBy(x: 0, y: size.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.setBlendMode(.normal)

        let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        context.clip(to: rect, mask: cgImage!)

        color.setFill()
        context.fill(rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return newImage
    }
}