如何从另一个 UIPickerview 更改 UIPickerView 的字符串？
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【中文标题】如何从另一个 UIPickerview 更改 UIPickerView 的字符串？【英文标题】：How can I change the strings of a UIPickerView from another UIPickerview? 【发布时间】：2015-09-24 19:18:48 【问题描述】：我的视图控制器中有两个UIPickerview、pickerView1 和pickerView2。
我想在这里实现的是，当我从pickerView1 中选择一个字符串时，它会自动更改pickerView2 的字符串。
我创建了第 3 部分，因为有很多字符串，理想情况下，我希望这一切都在第 1 部分中，因为我目前将代码设置为 3 个选择器视图，但我只想要两个选择器视图。
这是一个例子。
Pickerview1 包含 "a","b","c","d"。
如果选择“a”，pickerView2 将显示特定的字符串以供选择，如果我选择“b”，则“a”的字符串不会显示，但“b”的字符串将单独显示.
在第 2 节中，我希望这些字段中的每一个都与第 1 节和第 3 节中定义的子字符串对应，然后填充第二个 UIpickerview，所以每次我在第一个选择器视图中选择一个字符串时，第二个 uipickerview为此生成特定的字符串。
这是我的代码：
//PickerView Category IBOutlets
@IBOutlet var pickerView1: UIPickerView! = UIPickerView()
@IBOutlet var pickerView2: UIPickerView! = UIPickerView()
@IBOutlet var pickerView3: UIPickerView! = UIPickerView()
@IBOutlet var textField1: UITextField! = UITextField()
@IBOutlet var textField2: UITextField! = UITextField()
@IBOutlet var textField3: UITextField! = UITextField()
var SECTION2 = ["Select", "Criminal Activity", "Begging","Harassment", "Criminal Damage", "Disruption Of Service", "Drunken Behaviour","Fare Evasion", "Feet on Seats", "Hate Crime", "Inappropriate Sexual Behaviour", "Litter", "Missile Throwing", "Noise","Rowdy Behaviour", "Smoking Tobacco", "Drugs", "Threats/abuse/intimidation towards Staff", "Threats/abuse/intimdation towards Passengers" ]
var SECTION1 = ["Select", "*>>>Criminal Activity<<<*", "Assault", "Arson", "Trespass", "Spitting", "*>>>Begging<<<*", "On Board", "Off Board", "*>>>Harassment<<<*", "Stalking", "On Board", "At Stop/Station", "Bullying", "*>>>Criminal Damage<<<*", "Damage to Exterior", "Damage to Interior", "Glass Breakage","Grafitti", "Window Etching", "*>>>Disruption Of Service<<<*", "Interfering with the engine", "Opening emergency exits", "Pressing emergency stop/handles", "Throwing debris on to the line/track", "*>>>Drunken Behaviour<<<*", "Drinking on the mode of transport", "Drinking in the station/stop", "Aggressive Drunks", "*>>>Fare Evasion<<<*", "Fraudulent Pass", "None payment of fare", "*>>>Feet on Seats<<<*", "Purposeful Obstruction" ]
var SECTION3 = ["Select", "*>>>Hate Crime<<<*", "Disability", "Ethnicity", "Gender", "Race","Religion", "Sexual Orientation", "*>>>Litter<<<*", "On Board", "At station/stop", "*>>>Missile Throwing<<<*", "Stone Throwing", "Throwing Objects", "*>>>Noise<<<*", "Inappropriate Musical Content", "Loud Music", "*>>>Rowdy Behaviour<<<*", "School Children", "Shouting/Swearing", "Within Shelter", "Within Station/Stop"," Groups/Gangs", "*>>>Smoking Tobacco<<<*", "On Board", "At station/stop", "*>>>Drugs<<<*", "Smoking Drugs", "Drug Paraphernalia", "Drug Taking", "Drug Dealing", "*>>>Threats/abuse/intimidation towards Staff<<<*", "On Board", "At station/stop", "*>>>Threats/abuse/intimidation towards Passengers<<<*", "On Board", "At station/stop" ]
override func viewDidLoad()
super.viewDidLoad()
var Viewcontroller: () =
pickerView1 = UIPickerView()
pickerView2 = UIPickerView()
pickerView3 = UIPickerView()
pickerView1.delegate = self
pickerView2.delegate = self
pickerView3.delegate = self
self.textField1.inputView = self.pickerView1;
self.textField2.inputView = self.pickerView2;
self.textField3.inputView = self.pickerView3;
pickerView1.tag = 0
pickerView2.tag = 1
pickerView3.tag = 2
textField1.inputView = pickerView1
textField2.inputView = pickerView2
textField3.inputView = pickerView3
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int
return 1
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
if pickerView.tag == 0
return SECTION1.count
else if pickerView.tag == 1
return SECTION2.count
else if pickerView.tag == 2
return SECTION3.count
return 1
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String!
if pickerView.tag == 0
return SECTION1[row]
else if pickerView.tag == 1
return SECTION2[row]
else if pickerView.tag == 2
return SECTION3[row]
return ""
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
if pickerView.tag == 0
textField1.text = SECTION1[row]
else if pickerView.tag == 1
textField2.text = SECTION2[row]
else if pickerView.tag == 2
textField3.text = SECTION3[row]
【问题讨论】：
【参考方案1】：设置全局变量
var data1:NSMutableArray=["Apple","Mango","Banana"]
var data2:NSMutableArray=[["greenApple","whiteApple","yellowApple"],["greenMango","whiteMango","yelloMango"],["greenBanana","whiteBanana","yellowBanana"]]
var data3:NSArray = []
设置pickerViews的标签——pickerView1（比如1）和pickerView2（比如2）。
override func viewDidLoad()
super.viewDidLoad()
pickerView1.tag=1;
pickerView2.tag=2;
data3=["greenApple","whiteApple","yellowApple"] //initialise the array with the data
在委托方法中设置标题
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String!
if pickerView.tag==1
return data1[row] as! String
else
return data3[row] as! String
在选择委托中，如果选择了选择器，则根据 pickerView1 选择为 data3 分配所需的数据并重新加载 pickerView2
func pickerView(pickerView: UIPickerView,
didSelectRow row: Int,
inComponent component: Int)
if pickerView.tag==1
data3=data2[row] as! NSArray
pickerView2.reloadAllComponents() // reload pickerview2
【讨论】：
我已经尝试了上面的代码，但是我仍然遇到错误，你能给我一个用“ViewController.swift”编写的代码的例子吗？谢谢。【参考方案2】：如果要符合这些协议，则需要实现 UIPickerViewDataSource 和 UIPickerViewDelegate 所需的所有方法。
并为 ViewController.swift 尝试此代码
导入 UIKit 导入基金会
类 ViewController: UIViewController, UITextFieldDelegate, UIPickerViewDataSource, UIPickerViewDelegate
@IBOutlet var pickerView1: UIPickerView! = UIPickerView()
@IBOutlet var pickerView2: UIPickerView! = UIPickerView()
@IBOutlet var textField1: UITextField! = UITextField()
@IBOutlet var textField2: UITextField! = UITextField()
var data1:NSMutableArray=["Apple","Mango","Banana"]
var data2:NSMutableArray=[["greenApple","whiteApple","yellowApple"],["greenMango","whiteMango","yelloMango"],["greenBanana","whiteBanana","yellowBanana"]]
var data3:NSArray = []
override func viewDidLoad()
super.viewDidLoad()
pickerView1.tag=1;
pickerView2.tag=2;
data3=["greenApple","whiteApple","yellowApple"] //initialise the array with the data
textField1.text = data1[0] as! String
textField2.text = data3[0] as! String
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int
return 1
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
return 3;
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String!
if pickerView.tag==1
return data1[row] as! String
else
return data3[row] as! String
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent 组件: Int)
if pickerView.tag==1
data3=data2[row] as! NSArray
pickerView2.reloadAllComponents() // reload pickerview2
if pickerView.tag==1
textField1.text = data1[row] as! String
else
textField2.text = data3[row] as! String
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
【讨论】：
我添加了一些额外的代码来让它工作，我现在的问题是当我在点击文本字段初始化之前启动应用程序时，“Apple”和“greenApple”出现在文本字段中选择器视图。另外如何在第一个pickerview和第二个pickerview中添加其他选项？以上是关于如何从另一个 UIPickerview 更改 UIPickerView 的字符串？的主要内容，如果未能解决你的问题，请参考以下文章
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