Question

如何在用户使用键盘时更改leftview图像颜色？如果userNameTextField不包含6个字母，我希望图像为红色。非常感谢你

这是我的左视图图片代码：

  userNameTextField.leftViewMode = UITextFieldViewMode.Always
        userNameTextField.leftView = UIImageView(image: UIImage(named: "Clipboard-20-2"))

Answer 1

只需将目标添加到UITextField以获取控件事件EditingChanged并检查发件人字符数是否小于6.您还需要将图像呈现模式设置为始终模板并将UITextField leftView tintColor属性设置为红色：

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var userNameTextField: UITextField!
    override func viewDidLoad() {
        super.viewDidLoad()
        if let templateImage = UIImage(named: "Clipboard-20-2")?.imageWithRenderingMode(.AlwaysTemplate) {  // it will only use your image silhouette tinted with blue or red color
            let imageView = UIImageView(image: templateImage)
            imageView.tintColor = UIColor.redColor()
            userNameTextField.leftViewMode = .Always
            userNameTextField.leftView = imageView
        }
        userNameTextField.addTarget(self, action: "textChanged:", forControlEvents: .EditingChanged)
    }
    func textChanged(sender: UITextField) {
        sender.leftView?.tintColor = sender.text?.characters.count < 6 ? UIColor.redColor() : nil
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

文本字段leftview图像颜色

1 个答案: