ios - 如何在编辑时更改 uitextfield leftView image tintColor

Question

我正在尝试实现 UITextField 编辑或不编辑这样的样式:

但对我来说最棘手的部分是如何更改左侧图像的色调。 到目前为止我已经做到了这一点:

我的代码:

UITextField

lazy var email: UITextField = {
    let name = UITextField()
    name.layer.cornerRadius = 17.5
    name.layer.borderColor = UIColor(red: 0.55, green: 0.61, blue: 0.69, alpha: 0.5).cgColor
    name.layer.borderWidth = 1.5
    name.placeholder = "Email"
    name.font = UIFont.systemFont(ofSize: 15)
    name.textColor = UIColor(red: 0.55, green: 0.61, blue: 0.69, alpha: 1)
    name.backgroundColor = .clear
    name.leftViewMode = UITextFieldViewMode.always
    name.delegate = self
    name.translatesAutoresizingMaskIntoConstraints = false
    return name
}()

左图功能:

func addLeftImageTo(txtField: UITextField, andImage img: UIImage) {

    let leftView = UIView(frame: CGRect(x: 0, y: 0, width: 42.75, height: 40))
    let centerX: CGFloat = (leftView.frame.midX) - (img.size.width / 2)
    let centerY: CGFloat = (leftView.frame.midY) - (img.size.height / 2)
    let leftImageView = UIImageView(frame: CGRect(x: centerX + 2 , y: centerY - 1, width: img.size.width, height: img.size.height))
    leftImageView.contentMode = .scaleAspectFit
    leftImageView.image = img
    leftView.addSubview(leftImageView)
    txtField.leftView = leftView
    txtField.leftViewMode = .always
}

添加左图:

let emailLeftImg = UIImage(named: "ic_txt_field_email")
addLeftImageTo(txtField: email, andImage: emailLeftImg!)

let passwordLeftImg = UIImage(named: "ic_txt_field_password")
addLeftImageTo(txtField: password, andImage: passwordLeftImg!)

编辑开始和结束:

func textFieldDidBeginEditing(_ textField: UITextField) {
    self.setTextBorder(textField: textField, color: UIColor.white, borderColor: UIColor.white, isSelected: true)

}

func textFieldDidEndEditing(_ textField: UITextField) {
    self.setTextBorder(textField: textField, color: UIColor.clear, borderColor: UIColor(red: 0.55, green: 0.61, blue: 0.69, alpha: 0.5),  isSelected: false)
}


func setTextBorder(textField: UITextField, color: UIColor, borderColor: UIColor, isSelected: Bool) {
    textField.backgroundColor = color
    textField.layer.borderColor = borderColor.cgColor
    textField.tintColor = UIColor(red: 1.0, green: 0.2, blue: 0.33, alpha: 1)
    textField.layer.masksToBounds = false

    if isSelected == true {
        textField.layer.shadowRadius = 3.0
        textField.layer.shadowColor = UIColor.black.cgColor
        textField.layer.shadowOffset = CGSize(width: 0, height: 2)
        textField.layer.shadowOpacity = 0.125
    } else {
        textField.layer.shadowRadius = 0
        textField.layer.shadowColor = UIColor.clear.cgColor
        textField.layer.shadowOffset = CGSize(width: 0, height: 0)
        textField.layer.shadowOpacity = 0
    }

}

我曾尝试添加此代码来更改图像颜色，但没有成功。

var picTintColor: Bool = false 

在 LeftImage 函数中:

if picTintColor == true {
        leftImageView.image = img.withRenderingMode(.alwaysTemplate)
        leftImageView.tintColor = .blue
    } else {
        leftImageView.image = img
    }

并在编辑 Begains 和 Ending 函数中:

if isSelected == true {
        picTintColor = true
    } else {
        picTintColor = false
    }

我是 IOS 编程的完全菜鸟，所以感谢您的耐心等待，并为我糟糕的英语感到抱歉。谢谢!

Answer 1

根据代码，它实际上不能将isSelected信号传递给leftImageView，可能是leftImageView get in laster 不是更早的，或者信号没有通过成功。 我建议采用一种简单的方法，只需在 editingBegains and Ending: 中执行您想要的操作即可更改 ImageView ，如下所示:

func textFieldDidBeginEditing(_ textField: UITextField) {
     let emailLeftImg = UIImage(named: "ic_txt_field_email")
     addLeftImageTo(txtField: email, andImage: emailLeftImg!)
}

func addLeftImageTo(txtField: UITextField, andImage img: UIImage) {

let leftView = UIView(frame: CGRect(x: 0, y: 0, width: 42.75, height: 40))
let centerX: CGFloat = (leftView.frame.midX) - (img.size.width / 2)
let centerY: CGFloat = (leftView.frame.midY) - (img.size.height / 2)
let leftImageView = UIImageView(frame: CGRect(x: centerX + 2 , y: centerY - 1, width: img.size.width, height: img.size.height))
leftImageView.contentMode = .scaleAspectFit
if picTintColor == true {
    leftImageView.image = img.withRenderingMode(.alwaysTemplate)
    leftImageView.tintColor = .blue
} else {
    leftImageView.image = img
}
leftView.addSubview(leftImageView)
txtField.leftView = leftView
txtField.leftViewMode = .always

} 最后是delgate方法，就是这样，你可以试试这个方法来测试。希望对你有帮助。