按下按钮后,如何使应用程序底部的UIPickerView上升？

Question

我正在通过制作iPhone应用程序来学习Swift.我遇到的问题涉及实现UIPickerView.我有一个按钮,如果按下该按钮,应该使UIPickerView从屏幕底部上升到主视图上的设定长度.然后,当用户从UIPickerView中选择一个项目时,UIPickerView会从主视图中下降,直到再次调用它为止.

我正在尝试复制的一个很好的例子是当你在Clock应用程序中添加一个警报时,没有视图覆盖所有内容而没有标签和没有开关.

我也希望从PickerView中选择的项目触发一个功能,但我认为这将是在我遇到这个障碍之后.

这是我到目前为止的相关代码.

@IBOutlet weak var pickerContainer: UIView!
@IBOutlet weak var pickerView: UIPickerView!
let picker_values = ["val 1", "val 2", "val 3", "val 4"];
    override func viewDidLoad() {
    super.viewDidLoad()

}


@IBAction func buttonPressed(sender: AnyObject) {
    print("pressing a die!");

}

提前致谢!

Answer 1

好的,你可以使用UITextField来做到这一点

第01步: -

添加UITextField.选择不可见的板样式并设置色调白色/透明色.

第02步: -

然后在UITextField的顶部添加一个UIButton,添加相同的宽度高度和约束.这是stroy board层次结构,

第03步: -

然后将BUTTON和TextField连接到此类函数: -

将按钮连接到此@IBAction func按钮(sender:AnyObject),并将UITextField连接到@IBAction func textField(sender:UITextField).

import UIKit

class ViewController: UIViewController, UITextFieldDelegate, UIPickerViewDataSource, UIPickerViewDelegate {

@IBOutlet weak var textFeild: UITextField!
let picker_values = ["val 1", "val 2", "val 3", "val 4"]
var myPicker: UIPickerView! = UIPickerView()

override func viewDidLoad() {
    super.viewDidLoad()
    self.myPicker = UIPickerView(frame: CGRectMake(0, 40, 0, 0))
    self.textFeild.delegate = self
    self.myPicker.delegate = self
    self.myPicker.dataSource = self
    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

//MARK: - Delegates and data sources

func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return picker_values.count
}

//MARK: Delegates

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return picker_values[row]
}

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    //Your Function
    print("Hello")
}

@IBAction func button(sender: AnyObject) {
    self.textFeild.becomeFirstResponder()
}

func cancelPicker(sender:UIButton) {
    //Remove view when select cancel
    self.textFeild.resignFirstResponder() // To resign the inputView on clicking done.
}

@IBAction func textField(sender: UITextField) {
    //Create the view
    let tintColor: UIColor = UIColor(red: 101.0/255.0, green: 98.0/255.0, blue: 164.0/255.0, alpha: 1.0)
    let inputView = UIView(frame: CGRectMake(0, 0, self.view.frame.width, 240))
    myPicker.tintColor = tintColor
    myPicker.center.x = inputView.center.x
    inputView.addSubview(myPicker) // add date picker to UIView
    let doneButton = UIButton(frame: CGRectMake(100/2, 0, 100, 50))
    doneButton.setTitle("Done", forState: UIControlState.Normal)
    doneButton.setTitle("Done", forState: UIControlState.Highlighted)
    doneButton.setTitleColor(tintColor, forState: UIControlState.Normal)
    doneButton.setTitleColor(tintColor, forState: UIControlState.Highlighted)
    inputView.addSubview(doneButton) // add Button to UIView
    doneButton.addTarget(self, action: "doneButton:", forControlEvents: UIControlEvents.TouchUpInside) // set button click event

    let cancelButton = UIButton(frame: CGRectMake((self.view.frame.size.width - 3*(100/2)), 0, 100, 50))
    cancelButton.setTitle("Cancel", forState: UIControlState.Normal)
    cancelButton.setTitle("Cancel", forState: UIControlState.Highlighted)
    cancelButton.setTitleColor(tintColor, forState: UIControlState.Normal)
    cancelButton.setTitleColor(tintColor, forState: UIControlState.Highlighted)
    inputView.addSubview(cancelButton) // add Button to UIView
    cancelButton.addTarget(self, action: "cancelPicker:", forControlEvents: UIControlEvents.TouchUpInside) // set button click event
    sender.inputView = inputView
}

}

顺便说一下,确保你UITextField发送的事件是"Edit Did Begin",如下所示: -

希望这会帮助你......

Answer 2

• 使用框架作为CGRectZero创建UIPickerView
• 创建一个UITextField.
• 将textField设置为隐藏.
• 创建一个UIButton.
• 单击按钮,调用textField.becomeFirstResponder()

而已!