如何调整UITextField.leftView的大小?

How to adjust the size of UITextField.leftView?

我正在尝试调整 UITextField 的左视图 UIImageView 的大小,但没有成功。图片总是很大。我希望它与我的 UITextField 具有相同的高度。这是我尝试过的:

结果:

let topContainer: UIView = {
    let view = UIView()
    view.layer.borderWidth = 1.0
    view.layer.borderColor = UIColor.appGrayExtraLightGray.cgColor
    view.layer.cornerRadius = 5
    view.clipsToBounds = true
    view.translatesAutoresizingMaskIntoConstraints = false
    return view
}()

let emailField: UITextField = {
    let view = UITextField()
    view.backgroundColor = UIColor.orange
    view.text = "myEmailAddress@gmail.com"
    view.font = UIFont.systemFont(ofSize: 14)
    view.translatesAutoresizingMaskIntoConstraints = false
    return view
}()

let s = view.safeAreaLayoutGuide

    topContainer.addSubview(emailField)
    emailField.topAnchor.constraint(equalTo: topContainer.topAnchor, constant: spacing).isActive = true
    emailField.leadingAnchor.constraint(equalTo: topContainer.leadingAnchor, constant: spacing).isActive = true
    emailField.trailingAnchor.constraint(equalTo: topContainer.trailingAnchor, constant: -spacing).isActive = true
    emailField.bottomAnchor.constraint(equalTo: topContainer.bottomAnchor, constant: -spacing).isActive = true

    /**Mail and clear button on eitherisde of textField*/
    let mailView = UIImageView.init(frame: CGRect.init(x: 0, y: 0, width: 15, height: 15)) // Chaning the GREct has no effect on the size!!
    mailView.image = UIImage.init(named: "mailGrayFilled")
    emailField.leftView = mailView
    emailField.leftViewMode = .always
    emailField.clearButtonMode = .always

    view.addSubview(topContainer)
    topContainer.topAnchor.constraint(equalTo: s.topAnchor, constant: spacing).isActive = true
    topContainer.leadingAnchor.constraint(equalTo: s.leadingAnchor, constant: spacing).isActive = true
    topContainer.trailingAnchor.constraint(equalTo: s.trailingAnchor, constant: -spacing).isActive = true

UIImageView 放入容器 UIView 似乎解决了我测试您的代码时的问题。这也可能允许您调整填充以满足您的需要。

let iconContainer = UIView(frame: CGRect(x: 0, y: 0, width: 25, height: 15))
let mailView = UIImageView(frame: CGRect(x: 0, y: 0, width: 15, height: 15))
mailView.image = UIImage(named: "mailGrayFilled")
mailView.contentMode = .scaleAspectFit
iconContainer.addSubview(mailView)
emailField.leftViewMode = .always
emailField.leftView = iconContainer
emailField.clearButtonMode = .always