以编程方式Swift在UIView上添加UITextField

Question

我是Swift和iOS编程的新手.我试图UITextField使用Swift 以编程方式创建,但无法正确使用它.另外你如何改变它以使半透明效果淡入背景？

var myField: UITextField = UITextField (frame:CGRectMake(10, 10, 30, 10));
self.addSubview(myField)

Answer 1

Swift 3和Swift 4.2:

override func viewDidLoad() {
    super.viewDidLoad()

    let sampleTextField =  UITextField(frame: CGRect(x: 20, y: 100, width: 300, height: 40))
    sampleTextField.placeholder = "Enter text here"
    sampleTextField.font = UIFont.systemFont(ofSize: 15)
    sampleTextField.borderStyle = UITextField.BorderStyle.roundedRect
    sampleTextField.autocorrectionType = UITextAutocorrectionType.no
    sampleTextField.keyboardType = UIKeyboardType.default
    sampleTextField.returnKeyType = UIReturnKeyType.done
    sampleTextField.clearButtonMode = UITextField.ViewMode.whileEditing
    sampleTextField.contentVerticalAlignment = UIControl.ContentVerticalAlignment.center
    sampleTextField.delegate = self
    self.view.addSubview(sampleTextField)
}

代表方法:

// MARK:- ---> UITextFieldDelegate

extension ViewController: UITextFieldDelegate {

    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        // return NO to disallow editing.
        print("TextField should begin editing method called")
        return true
    }

    func textFieldDidBeginEditing(_ textField: UITextField) {
        // became first responder
        print("TextField did begin editing method called")
    }

    func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {
        // return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end
        print("TextField should snd editing method called")
        return true
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        // may be called if forced even if shouldEndEditing returns NO (e.g. view removed from window) or endEditing:YES called
        print("TextField did end editing method called")
    }

    func textFieldDidEndEditing(_ textField: UITextField, reason: UITextFieldDidEndEditingReason) {
        // if implemented, called in place of textFieldDidEndEditing:
        print("TextField did end editing with reason method called")
    }

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        // return NO to not change text
        print("While entering the characters this method gets called")
        return true
    }

    func textFieldShouldClear(_ textField: UITextField) -> Bool {
        // called when clear button pressed. return NO to ignore (no notifications)
        print("TextField should clear method called")
        return true
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        // called when 'return' key pressed. return NO to ignore.
        print("TextField should return method called")
        // may be useful: textField.resignFirstResponder()
        return true
    }

}

// MARK: UITextFieldDelegate <---

Swift 2.0:

let sampleTextField = UITextField(frame: CGRectMake(20, 100, 300, 40))
sampleTextField.placeholder = "Enter text here"
sampleTextField.font = UIFont.systemFontOfSize(15)
sampleTextField.borderStyle = UITextBorderStyle.RoundedRect
sampleTextField.autocorrectionType = UITextAutocorrectionType.No
sampleTextField.keyboardType = UIKeyboardType.Default
sampleTextField.returnKeyType = UIReturnKeyType.Done
sampleTextField.clearButtonMode = UITextFieldViewMode.WhileEditing;
sampleTextField.contentVerticalAlignment = UIControlContentVerticalAlignment.Center
sampleTextField.delegate = self
self.view.addSubview(sampleTextField)

代表方法:

    // MARK:- ---> Textfield Delegates
    func textFieldDidBeginEditing(textField: UITextField) {
        print("TextField did begin editing method called")
    }

    func textFieldDidEndEditing(textField: UITextField) {
        print("TextField did end editing method called")
    }

    func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
        print("TextField should begin editing method called")
        return true;
    }

    func textFieldShouldClear(textField: UITextField) -> Bool {
        print("TextField should clear method called")
        return true;
    }

    func textFieldShouldEndEditing(textField: UITextField) -> Bool {
        print("TextField should snd editing method called")
        return true;
    }

    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
        print("While entering the characters this method gets called")
        return true;
    }

    func textFieldShouldReturn(textField: UITextField) -> Bool {
        print("TextField should return method called")
        textField.resignFirstResponder();
        return true;
    }
    // MARK: Textfield Delegates <---

Answer 2

self.addSubview(myTextField)

如果您正在使用子类,那么只能工作UIView.

您必须将其添加为ViewController层次结构的UIView的子视图.

var txtField: UITextField = UITextField(frame: CGRect(x: 0, y: 0, width: 500.00, height: 30.00));
self.view.addSubview(txtField)

默认情况下,背景颜色为白色,可能不会显示.您需要提供样式以及文本颜色和背景颜色.

txtField.borderStyle = UITextBorderStyle.Line
txtField.text = "myString" 
txtField.backgroundColor = UIColor.redColor()

有关详细信息,请点击此处

Answer 3

更新了Swift 3和Xcode 8.2

    let stepsTextField = UITextField(frame: CGRect(x: 20, y: 100, width: 300, height: 40))
    stepsTextField.placeholder = "Enter text here"
    stepsTextField.font = UIFont.systemFont(ofSize: 15)
    stepsTextField.borderStyle = UITextBorderStyle.roundedRect
    stepsTextField.autocorrectionType = UITextAutocorrectionType.no
    stepsTextField.keyboardType = UIKeyboardType.default
    stepsTextField.returnKeyType = UIReturnKeyType.done
    stepsTextField.clearButtonMode = UITextFieldViewMode.whileEditing;
    stepsTextField.contentVerticalAlignment = UIControlContentVerticalAlignment.center

Answer 4

您需要添加文本字段self.view而不是self.

var myField: UITextField = UITextField (frame:CGRectMake(10, 10, 30, 10));
self.view.addSubview(myField) 

对于添加半透明模糊效果，已经有一些建议可用，您可以通过 -

UIView 边框具有淡入淡出或模糊效果

Answer 5

试试下面的代码

var textFiled = UITextField(frame: CGRectMake(20.0, 30.0, 100.0, 33.0))
        textFiled.backgroundColor = UIColor.redColor()
        textFiled.borderStyle = UITextBorderStyle.Line
        self.view.addSubview(textFiled)

Answer 6

您可以在 Swift 5.2 中使用以下代码：

lazy var titleTextField:UITextField = {
    let textField = UITextField()
    textField.translatesAutoresizingMaskIntoConstraints = false
    textField.placeholder = "Title *"
    textField.keyboardType = UIKeyboardType.default
    textField.returnKeyType = UIReturnKeyType.done
    textField.autocorrectionType = UITextAutocorrectionType.no
    textField.font = UIFont.systemFont(ofSize: 13)
    textField.borderStyle = UITextField.BorderStyle.roundedRect
    textField.clearButtonMode = UITextField.ViewMode.whileEditing;
    textField.contentVerticalAlignment = UIControl.ContentVerticalAlignment.center
    return textField
}()