使用自定义样式在 Swift 中创建 UITextField 扩展

Question

我在视图上有几个必须看起来相同的 UITextField。我发现我可能会创建一个扩展来预先设置我的文本字段的样式（那些我想要具有相同样式的字段）。

let passTextField: UITextField = {
    let tf = UITextField()
    //tf.backgroundColor = UIColor.blueColor()
    tf.translatesAutoresizingMaskIntoConstraints = false
    tf.layer.cornerRadius = 25
    tf.layer.borderColor = UIColor(r: 34, g: 140, b: 204, a: 1).CGColor
    tf.layer.borderWidth = 2.0
    tf.layer.masksToBounds = true
    /* Paddings */
    tf.leftView = UIView(frame: CGRectMake(0, 0, 25, 0))
    tf.leftViewMode = UITextFieldViewMode.Always
    tf.rightView = UIView(frame: CGRectMake(0, 0, 25, 0))
    tf.rightViewMode = UITextFieldViewMode.Always
    /* Place Holder Formating */
    let attributes = [
        NSForegroundColorAttributeName: UIColor(r: 34, g: 140, b: 204, a: 1),
        NSFontAttributeName : UIFont(name: "HelveticaNeue-Thin", size: 16)! // Note the !
    ]
    tf.attributedPlaceholder = NSAttributedString(string: "Email", attributes:attributes)


    return tf
}()

所以这些属性中的大部分都应该包含在扩展中，我希望能够在声明变量时向其中添加几个属性。

你能帮帮我吗？我一直在寻找如何创建扩展程序，但似乎没有什么适合我的。

谢谢！

Answer 1

你可以用 extension 定义来完成，如果方法是新的你可以使用下面的代码，如果已经存在则创建一个 override 方法

extension UITextField {

    func underlined(){
        let border = CALayer()
        let width = CGFloat(1.0)
        border.borderColor = UIColor.lightGrayColor().CGColor
        border.frame = CGRect(x: 0, y: self.frame.size.height - width, width:  self.frame.size.width, height: self.frame.size.height)
        border.borderWidth = width
        self.layer.addSublayer(border)
        self.layer.masksToBounds = true
    }
}

Answer 2

像这样创建 extension 个 UITextField

extension UITextField {
    class func attributedTextField(frame: CGRect) -> UITextField {
        let textField = UITextField(frame: frame)
        textField.translatesAutoresizingMaskIntoConstraints = false
        textField.layer.cornerRadius = 25
        textField.layer.borderColor = UIColor(r: 34, g: 140, b: 204, a: 1).CGColor
        textField.layer.borderWidth = 2.0
        textField.layer.masksToBounds = true
        /* Paddings */
        textField.leftView = UIView(frame: CGRectMake(0, 0, 25, 0))
        textField.leftViewMode = UITextFieldViewMode.Always
        textField.rightView = UIView(frame: CGRectMake(0, 0, 25, 0))
        textField.rightViewMode = UITextFieldViewMode.Always
        /* Place Holder Formating */
        textField attributes = [
                          NSForegroundColorAttributeName: UIColor(r: 34, g: 140, b: 204, a: 1),
                          NSFontAttributeName : UIFont(name: "HelveticaNeue-Thin", size: 16)! // Note the !
                          ]
        textField.attributedPlaceholder = NSAttributedString(string: "Email", attributes:attributes)
        return textField
    } 
}

像这样调用这个函数

let tf = UITextField.attributedTextField(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

Answer 3

Swift 4: 在 UITextField 上使用 UITextField Extension =]@IBOutlet

@IBOutlet weak var normalTextField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()
    normalTextField.toStyledTextField()
}
extension UITextField {
    func toStyledTextField() { // Give Round Border and Left Placholder Padding
        self.layer.masksToBounds = true
        self.layer.cornerRadius = 10
        self.leftView = UIView(frame: CGRect(x: 0, y: 0, width: 15, height: 0))
        self.leftViewMode = UITextField.ViewMode.always
    }
}

使用自定义样式在 Swift 中创建 UITextField 扩展

Create UITextField Extension in Swift with custom styling

xcode

ios

swift

swift2