相對應的iOS的為滾輪PickerView
1.首先在Main.storyboard拖拉一個Picker View元件
將dataSource與delegate拉致上方圖片上三個小圖的最左邊小圖關聯
3.ViewController繼承UIPickerViewDelegate, UIPickerViewDataSource
4.ViewController.swift
//
// ThreePickerViewController.swift
// MultiplePickerViewTest
//
// Created by Terry Yang on 2017/6/18.
// Copyright © 2017年 terryyamg. All rights reserved.
//
import UIKit
class ThreePickerViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
@IBOutlet weak var picker3: UIPickerView!
//第一輪
var list1 = ["亞洲","歐洲"]
//第二輪
var list21 = ["日本","台灣"]
var list22 = ["英國","德國","義大利"]
//第三輪
var list211 = ["東京","沖繩","北海道"]
var list212 = ["台北","台中","台南","高雄","台東"]
var list221 = ["倫敦"]
var list222 = ["柏林"]
var list223 = ["羅馬"]
//init
var island : String = "亞洲"
var country : String = "日本"
var city : String = ""
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
picker3.delegate = self
picker3.dataSource = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//幾個滾輪
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 3
}
//確認各個滾輪有幾筆
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
//component - 第幾個滾輪
switch(component){
case 0:
return list1.count
case 1:
return island == "亞洲" ? list21.count : list22.count
case 2:
switch country {
case "日本":
return list211.count
case "台灣":
return list212.count
case "英國":
return list221.count
case "德國":
return list222.count
case "義大利":
return list223.count
default:
return 0
}
default:
return 0
}
}
//放入內容
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
switch(component){
case 0:
return list1[row]
case 1:
//true: 回傳第二輪的亞洲內容 false: 回傳第二輪的歐洲內容
return island == "亞洲" ? list21[row] : list22[row]
case 2:
switch country {
case "日本":
return list211[row]
case "台灣":
return list212[row]
case "英國":
return list221[row]
case "德國":
return list222[row]
case "義大利":
return list223[row]
default:
return nil
}
default:
return nil
}
}
//回傳選擇的字串
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
switch component {
case 0:
island = list1[row]
updateCountry(0)
updateCity(0)
print("洲: \(island)")
//選擇第一個滾輪後-重新載入
pickerView.reloadAllComponents()
//第二個與第三個滾輪回到第一個項目
pickerView.selectRow(0, inComponent: 1, animated: true)
pickerView.selectRow(0, inComponent: 2, animated: true)
case 1:
updateCountry(row)
updateCity(0)
print("國: \(country)")
//選擇第二個滾輪後-重新載入
pickerView.reloadAllComponents()
//第三個滾輪回到第一個項目
pickerView.selectRow(0, inComponent: 2, animated: true)
case 2:
updateCity(row)
print("城: \(city)")
default:
print("無")
}
}
func updateCountry(_ row: Int){
if island == "亞洲" {
country = list21[row]
} else {
country = list22[row]
}
}
func updateCity(_ row: Int){
switch country {
case "日本":
city = list211[row]
case "台灣":
city = list212[row]
case "英國":
city = list221[row]
case "德國":
city = list222[row]
case "義大利":
city = list223[row]
default:
print("無")
}
}
}
https://github.com/terryyamg/MultiplePickerViewTest
參考來源:
http://stackoverflow.com/questions/30832489/reload-component-in-ui-picker-view-swift
https://stackoverflow.com/questions/11191062/how-to-reset-uipickerview-to-index0-iphone
