如何让 UIPickerView 在按下按钮后从应用程序底部升起？

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方的设定长度。然后，当用户从 UIPickerView 中选择一个项目时，UIPickerView 会从主视图中下降，直到再次被调用。

我试图复制的一个很好的例子是，当您在时钟应用程序中添加闹钟时，没有视图覆盖所有内容，没有标签，也没有开关。

我还想让我从 PickerView 中选择的项目触发一个函数，但我认为那是在我克服这个障碍之后。

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

步骤01：-

添加 UITextField。选择您的板样式不可见并设置色调颜色白色/透明颜色。

步骤02：-

然后在 UITextField 的顶部添加一个 UIButton，添加相同的宽度高度和约束。这是故事板层次结构，

步骤03：-

然后将 BUTTON 和 TextField 连接到此类函数：-

将按钮连接到这个@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
}

}

顺便确保您的 UITextField 发送的事件是“编辑已开始”，如下所示：-

希望这对您有帮助...

Answer 2

• 创建一个 UIPickerView，框架为 CGRectZero
• 创建一个 UITextField。
• 将文本字段设置为隐藏。
• 创建一个 UIButton。
• 单击按钮时，调用 textField.becomeFirstResponder()

就是这样！

Answer 3

1. 在视图顶部添加 UITextField

2. 将边框样式设置为“无”，并将清除按钮设置为“从不出现”

3. 将 UITextField 出口附加到视图控制器。

4. 编写以下代码将文本字段的输入视图设置为选择器视图：

   - (void)setupPickerView
   {
   
        UIPickerView *pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 200, [UIScreen mainScreen].bounds.size.width, 225)];
   pickerView.backgroundColor = [UIColor colorWithRed:210/255.0 green:212/255.0 blue:217/255.0 alpha:1.0];
   
   pickerView.delegate = self;
   pickerView.dataSource = self;
   
   UIToolbar *toolBar = [[UIToolbar alloc] init];
   toolBar.barStyle = UIBarStyleDefault;
   toolBar.translucent = YES;
   [toolBar sizeToFit];
   
   UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStyleDone target:self action:@selector(donePicker)];
   UIBarButtonItem *spaceButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
   UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithTitle:@"Cancel" style:UIBarButtonItemStylePlain target:self action:@selector(donePicker)];
   
   [toolBar setItems:@[cancelButton, spaceButton, doneButton] animated:YES];
   toolBar.userInteractionEnabled = YES;
   
   self.textField.inputView = pickerView;
   self.textField.inputAccessoryView = toolBar;
   }
   

5. 相应地处理 UIPickerView delegate 和 dataSource 方法。