如何更改UISearchBar占位符和图像色调？

Question

我一直在尝试搜索结果几个小时,但我无法理解这一点.也许这是不可能的.我正在尝试更改UISearchBar的占位符文本和放大镜的色调颜色.如果重要的话,我只针对iOS 8.0+.这是我的代码和它现在的样子:

let searchBar = UISearchBar()
searchBar.placeholder = "Search"
searchBar.searchBarStyle = UISearchBarStyle.Minimal
searchBar.tintColor = UIColor.whiteColor()

我希望搜索和放大镜是白色的,或者可能是深绿色.

Answer 1

细节

• Xcode版本10.1(10B61)
• Swift 4.2

解

import UIKit

extension UISearchBar {

    func getTextField() -> UITextField? { return value(forKey: "searchField") as? UITextField }
    func set(textColor: UIColor) { if let textField = getTextField() { textField.textColor = textColor } }
    func setPlaceholder(textColor: UIColor) { getTextField()?.setPlaceholder(textColor: textColor) }
    func setClearButton(color: UIColor) { getTextField()?.setClearButton(color: color) }

    func setTextField(color: UIColor) {
        guard let textField = getTextField() else { return }
        switch searchBarStyle {
        case .minimal:
            textField.layer.backgroundColor = color.cgColor
            textField.layer.cornerRadius = 6
        case .prominent, .default: textField.backgroundColor = color
        @unknown default: break
        }
    }

    func setSearchImage(color: UIColor) {
        guard let imageView = getTextField()?.leftView as? UIImageView else { return }
        imageView.tintColor = color
        imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate)
    }
}

private extension UITextField {

    private class Label: UILabel {
        private var _textColor = UIColor.lightGray
        override var textColor: UIColor! {
            set { super.textColor = _textColor }
            get { return _textColor }
        }

        init(label: UILabel, textColor: UIColor = .lightGray) {
            _textColor = textColor
            super.init(frame: label.frame)
            self.text = label.text
            self.font = label.font
        }

        required init?(coder: NSCoder) { super.init(coder: coder) }
    }


    private class ClearButtonImage {
        static private var _image: UIImage?
        static private var semaphore = DispatchSemaphore(value: 1)
        static func getImage(closure: @escaping (UIImage?)->()) {
            DispatchQueue.global(qos: .userInteractive).async {
                semaphore.wait()
                DispatchQueue.main.async {
                    if let image = _image { closure(image); semaphore.signal(); return }
                    guard let window = UIApplication.shared.windows.first else { semaphore.signal(); return }
                    let searchBar = UISearchBar(frame: CGRect(x: 0, y: -200, width: UIScreen.main.bounds.width, height: 44))
                    window.rootViewController?.view.addSubview(searchBar)
                    searchBar.text = "txt"
                    searchBar.layoutIfNeeded()
                    _image = searchBar.getTextField()?.getClearButton()?.image(for: .normal)
                    closure(_image)
                    searchBar.removeFromSuperview()
                    semaphore.signal()
                }
            }
        }
    }

    func setClearButton(color: UIColor) {
        ClearButtonImage.getImage { [weak self] image in
            guard   let image = image,
                let button = self?.getClearButton() else { return }
            button.imageView?.tintColor = color
            button.setImage(image.withRenderingMode(.alwaysTemplate), for: .normal)
        }
    }

    var placeholderLabel: UILabel? { return value(forKey: "placeholderLabel") as? UILabel }

    func setPlaceholder(textColor: UIColor) {
        guard let placeholderLabel = placeholderLabel else { return }
        let label = Label(label: placeholderLabel, textColor: textColor)
        setValue(label, forKey: "placeholderLabel")
    }

    func getClearButton() -> UIButton? { return value(forKey: "clearButton") as? UIButton }
}

完整样本

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let searchBar = UISearchBar(frame: CGRect(x: 0, y: 20, width: UIScreen.main.bounds.width, height: 44))
        searchBar.searchBarStyle = .default
        view.addSubview(searchBar)

        searchBar.placeholder = "placeholder"
        searchBar.set(textColor: .brown)
        searchBar.setTextField(color: UIColor.green.withAlphaComponent(0.3))
        searchBar.setPlaceholder(textColor: .white)
        searchBar.setSearchImage(color: .white)
        searchBar.setClearButton(color: .red)
    }
}

结果

Answer 2

如果您有可以使用的自定义图像,则可以使用类似于以下内容的方式设置图像并更改占位符文本颜色:

[searchBar setImage:[UIImage imageNamed:@"SearchWhite"] forSearchBarIcon:UISearchBarIconSearch state:UIControlStateNormal];

UITextField *searchTextField = [searchBar valueForKey:@"_searchField"];    
if ([searchTextField respondsToSelector:@selector(setAttributedPlaceholder:)]) {
    UIColor *color = [UIColor purpleColor];
    [searchTextField setAttributedPlaceholder:[[NSAttributedString alloc] initWithString:@"Search" attributes:@{NSForegroundColorAttributeName: color}]];
}

在该示例中,我使用了purpleColor,您可以使用该+ (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha方法创建自定义深绿色.

编辑:我刚刚意识到你正在迅速写出来......呃.快速键入这个,所以我没有在Obj-C中留下答案.

    searchBar.setImage(UIImage(named: "SearchWhite"), forSearchBarIcon: UISearchBarIcon.Search, state: UIControlState.Normal);

    var searchTextField: UITextField? = searchBar.valueForKey("searchField") as? UITextField
    if searchTextField!.respondsToSelector(Selector("attributedPlaceholder")) {
        var color = UIColor.purpleColor()
        let attributeDict = [NSForegroundColorAttributeName: UIColor.purpleColor()]
        searchTextField!.attributedPlaceholder = NSAttributedString(string: "search", attributes: attributeDict)
    }

Swift 3.0

    var searchTextField: UITextField? = searchBar.value(forKey: "searchField") as? UITextField
    if searchTextField!.responds(to: #selector(getter: UITextField.attributedPlaceholder)) {
        let attributeDict = [NSForegroundColorAttributeName: UIColor.white]
        searchTextField!.attributedPlaceholder = NSAttributedString(string: "Search", attributes: attributeDict)
    }

Answer 3

Swift 3:如果你想改变占位符,按钮和放大镜玻璃

    let textFieldInsideSearchBar = searchBar.value(forKey: "searchField") as? UITextField
    textFieldInsideSearchBar?.textColor = UIColor.white

    let textFieldInsideSearchBarLabel = textFieldInsideSearchBar!.value(forKey: "placeholderLabel") as? UILabel
    textFieldInsideSearchBarLabel?.textColor = UIColor.white

    let clearButton = textFieldInsideSearchBar?.value(forKey: "clearButton") as! UIButton
    clearButton.setImage(clearButton.imageView?.image?.withRenderingMode(.alwaysTemplate), for: .normal)
    clearButton.tintColor = UIColor.white

    let glassIconView = textFieldInsideSearchBar?.leftView as? UIImageView

    glassIconView?.image = glassIconView?.image?.withRenderingMode(.alwaysTemplate)
    glassIconView?.tintColor = UIColor.white