iOS控件UIPickerView和DatePicker可实现滑动选择功能。基于UIPickerView封装多级联动(必须将可供选择的数据缓存本地)，如省市区选择实现,效果如下：
Simulator Screen Shot 01.png
自定义LmyPickerObject类，定义要显示的标题、下一集子菜单集合，如果选择省市区可添加属性code。
public class LmyPickerObject: NSObject {
var title:String?
var subArray:[LmyPickerObject]?
var code:String?
}
设置枚举，融合两种选择器可配置，还可添加其他可操作功能实现我们想要的效果。
public enum LmyPickerStyle : Int32 {
case nomal
case date
}
protocol PickerDelegate : NSObjectProtocol {
func chooseElements(picker: LmyPicker, content: [Int:Int])
func chooseDate(picker: LmyPicker, date: Date)
}
初始化LmyPicker，init方法
var pickerDelegate : PickerDelegate?
private let picker_height:CGFloat! = 260
private var picker: UIPickerView = UIPickerView()
private var datePicker: UIDatePicker = UIDatePicker()
private var content: [LmyPickerObject]?
private var pickerStyle: LmyPickerStyle?
private var backgroundBtn: UIButton = UIButton()
private var tempDic: Dictionary = [Int:Int]()
private var numComponents:Int = 0
var contentArray:[LmyPickerObject]? {
get {
return self.content
}
set {
self.content = newValue
self.initializeContentArray()
}
}
init(delegate: PickerDelegate, style: LmyPickerStyle) {
pickerDelegate = delegate
pickerStyle = style
let v_frame = CGRect(x: 0, y: UIScreen.height, width: UIScreen.width, height: picker_height)
super.init(frame: v_frame)
let view = UIView(frame: CGRect(x: 0, y: 0, width: UIScreen.width, height: 44))
view.backgroundColor = UIColor.RGBA(230, 230, 230, 1)
self.addSubview(view)
let cancelBtn = UIButton(type: UIButtonType.system)
cancelBtn.frame = CGRect(x: 0, y: 0, width: 60, height: 44)
cancelBtn.titleLabel?.font = UIFont.systemFont(ofSize: 16)
cancelBtn.setTitle("取 消", for: UIControlState.normal)
cancelBtn.setTitleColor(UIColor.RGBA(18, 93, 255, 1), for: UIControlState.normal)
cancelBtn.addTarget(self, action: #selector(cancelButtonClick), for: .touchUpInside)
self.addSubview(cancelBtn)
let doneBtn = UIButton(type: UIButtonType.system)
doneBtn.frame = CGRect(x: UIScreen.width - 60, y: 0, width: 60, height: 44)
doneBtn.titleLabel?.font = UIFont.systemFont(ofSize: 16)
doneBtn.setTitle("确 定", for: UIControlState.normal)
doneBtn.setTitleColor(UIColor.RGBA(18, 93, 255, 1), for: UIControlState.normal)
doneBtn.addTarget(self, action: #selector(doneButtonClick), for: .touchUpInside)
self.addSubview(doneBtn)
backgroundBtn = UIButton(type: UIButtonType.system)
backgroundBtn.frame = CGRect(x: 0, y: 0, width: UIScreen.width, height: UIScreen.height)
backgroundBtn.backgroundColor = UIColor.RGBA(0, 0, 0, 0.0)
switch style {
case .nomal:
self.picker = UIPickerView(frame: CGRect(x: 0, y: 44, width: UIScreen.width, height: picker_height - 44))
self.picker.delegate = self
self.picker.dataSource = self
self.picker.backgroundColor = UIColor.white
self.addSubview(self.picker)
case .date:
self.datePicker = UIDatePicker(frame: CGRect(x: 0, y: 44, width: UIScreen.width, height: picker_height - 44))
self.datePicker.datePickerMode = UIDatePickerMode.date
self.datePicker.locale = Locale(identifier: "zh_CN")
self.datePicker.backgroundColor = UIColor.white
self.datePicker.addTarget(self, action: #selector(self.dateChoosePressed(datePicker:)), for: .valueChanged)
self.addSubview(self.datePicker)
}
}
private func initializeContentArray() {
var temp:Int = 0
if let array = content {
if array.count > 0 {
temp = 1
tempDic[temp - 1] = 0
var object = array.first
while object?.subArray != nil {
temp += 1
tempDic[temp - 1] = 0
let arr = object?.subArray
if let temp_arr = arr {
if temp_arr.count > 0 {
object = temp_arr.first
}else {
break
}
}else{
break
}
}
}
}
numComponents = temp
picker.reloadAllComponents()
}
public func show() {
UIApplication.shared.keyWindow?.addSubview(self.backgroundBtn)
UIApplication.shared.keyWindow?.addSubview(self)
UIView.animate(withDuration: 0.35, animations: {
self.backgroundBtn.backgroundColor = UIColor.RGBA(0, 0, 0, 0.3)
self.top = UIScreen.height - self.picker_height
}) { (finished: Bool) in
}
}
private func hiddenPicker() {
UIView.animate(withDuration: 0.35, animations: {
self.backgroundBtn.backgroundColor = UIColor.RGBA(0, 0, 0, 0.0)
self.top = UIScreen.height
}) { (finished: Bool) in
for view in self.subviews {
view.removeFromSuperview()
}
self.removeFromSuperview()
self.backgroundBtn.removeFromSuperview()
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
UIPickerViewDelegate,UIPickerViewDataSource 时间方法，数据处理关键：
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return numComponents
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
var row:Int = 0
if let array = content {
var tempArray:Array = array
for i in 0...numComponents {
let value:Int = tempDic[i] ?? 0
if component == i {
row = tempArray.count
}
if tempArray.count > value {
let object = tempArray[value]
if let arr = object.subArray {
tempArray = arr
}else {
tempArray = [LmyPickerObject]()
}
}
if component == i {
return row
}
}
return 0
}
return 0
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerStyle == .nomal {
self.picker_partingLine(color: UIColor.lightGray)
}
var str:String = ""
if let array = content {
var tempArray:Array = array
for i in 0...numComponents {
let value:Int = tempDic[i] ?? 0
if component == i {
let object = tempArray[row]
str = object.title ?? "未知"
}
if tempArray.count > value {
let object = tempArray[value]
if let arr = object.subArray {
tempArray = arr
}else {
tempArray = [LmyPickerObject]()
}
}
}
return str
}
return ""
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
tempDic.updateValue(row, forKey: component)
if (component + 1) < numComponents {
for i in (component+1)..<numComponents {
tempDic.updateValue(0, forKey:i)
pickerView.selectRow(0, inComponent: i, animated: false)
}
}
pickerView.reloadAllComponents()
}
func dateChoosePressed(datePicker: UIDatePicker) {
//print("select date \(datePicker.date.string_from(formatter: "yyyy-MM-dd"))")
}
点击取消或确定，将结果传到相应控制器：
func doneButtonClick() {
if pickerStyle == .nomal {
pickerDelegate?.chooseElements(picker: self, content: tempDic)
}else {
pickerDelegate?.chooseDate(picker: self, date: datePicker.date)
}
self.hiddenPicker()
}
func cancelButtonClick(btn:UIButton) {
self.hiddenPicker()
}
另外，不知为何从iOS10开始UIPickerView显示选项分割线消失了，从网上找到代码完美解决，应该是默认clearColor了。
func picker_partingLine(color: UIColor?) {
let sep_color = color ?? UIColor.lightGray
if #available(iOS 10.0, *) {
for view in picker.subviews {
if view.height < 1 {
view.backgroundColor = sep_color
}
}
}
}
