我正在尝试从在线数据库中检索数据,并且成功完成了;但是,从数据库检索数据后,我想将其存储在数组中,然后用其数据填充 ListView 和 map View ,但有一个问题,我能够加载数据并存储并查看它,然而问题是,每次应用程序加载时都不会出现任何信息,直到我转到另一个场景并返回,因为我正在通过 AppDelegate 填充数组。但是,如果我通过 viewdidload 填充它,我的表格 View 中会出现重复的项目。
这是我的代码:
方法 1,这会导致重复
StoreViewController.swift
class StoreViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate, StoresModelProtocoal {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
drawForm()
setUpMap()
self.hideKeyboardWhenTappedAround()
getCurrentLocation()
let hideStoreDetail: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.hideStoreDetails))
Map.addGestureRecognizer(hideStoreDetail)
//Create a nib for the custom cell and use it in the table
let nib = UINib(nibName: "CustomStoreCell", bundle: nil)
StoresListTable.registerNib(nib, forCellReuseIdentifier: "customStoreCell")
let storesModel = StoresModel()
storesModel.delegate = self
storesModel.downloadItems()
}
func itemsDownloaded(items: NSArray) {
print("Items downloaded")
for item in items
{
if let s = item as? Store
{
print(s.Address)
Globals.unsortedStoresList += [s]
Map.addAnnotation(s.Annotation)
do_table_refresh()
}
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return Globals.unsortedStoresList.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:CustomStoreCell = self.StoresListTable.dequeueReusableCellWithIdentifier("customStoreCell") as! CustomStoreCell
let s = Globals.unsortedStoresList[indexPath.row]
cell.loadItem(s.Name, StoreAddress: s.Address, StoreHoursOfOperation: s.HoursOfOperation, StoreDistanceFromCurrentLocation: String(s.DistanceFromCurrentLocation))
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//tableView.deselectRowAtIndexPath(indexPath, animated: true)
let s = Globals.unsortedStoresList[indexPath.row]
print(s.Name)
print(s.Address)
print(s.HoursOfOperation)
print(s.DistanceFromCurrentLocation)
//print("You selected cell #\(indexPath.row)!")
}
func do_table_refresh()
{
dispatch_async(dispatch_get_main_queue(), {
self.StoresListTable.reloadData()
return
})
}
我知道这个会重复这些项目,因为每次加载 View 时,它都会再次重新下载所有数据;因此,我尝试寻找一种更好的方法,然后我考虑在我的 AppDelegate 中执行下载过程,然后编写几个从数组中获取数据并显示它的函数,但这里的问题是数据将显示在TableView 立即没有重复项,但第一次运行时不会显示在 map View 上,而是我必须转到另一个场景并返回才能将数据显示在 map 上。
方法 2
StoreViewController.swift
class StoreViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
drawForm()
setUpMap()
self.hideKeyboardWhenTappedAround()
getCurrentLocation()
let hideStoreDetail: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.hideStoreDetails))
Map.addGestureRecognizer(hideStoreDetail)
//Create a nib for the custom cell and use it in the table
let nib = UINib(nibName: "CustomStoreCell", bundle: nil)
StoresListTable.registerNib(nib, forCellReuseIdentifier: "customStoreCell")
loadMapAnnotations()
}
func loadMapAnnotations(){
for item in Globals.unsortedStoresList
{
Map.addAnnotation(item.Annotation)
do_table_refresh()
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return Globals.unsortedStoresList.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:CustomStoreCell = self.StoresListTable.dequeueReusableCellWithIdentifier("customStoreCell") as! CustomStoreCell
let s = Globals.unsortedStoresList[indexPath.row]
cell.loadItem(s.Name, StoreAddress: s.Address, StoreHoursOfOperation: s.HoursOfOperation, StoreDistanceFromCurrentLocation: String(s.DistanceFromCurrentLocation))
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//tableView.deselectRowAtIndexPath(indexPath, animated: true)
let s = Globals.unsortedStoresList[indexPath.row]
print(s.Name)
print(s.Address)
print(s.HoursOfOperation)
print(s.DistanceFromCurrentLocation)
//print("You selected cell #\(indexPath.row)!")
}
func do_table_refresh()
{
dispatch_async(dispatch_get_main_queue(), {
self.StoresListTable.reloadData()
return
})
}
AppDelegate.swift
class AppDelegate: UIResponder, UIApplicationDelegate, StoresModelProtocoal {
var window: UIWindow?
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let storesModel = StoresModel()
storesModel.delegate = self
storesModel.downloadItems()
return true
}
//////////////////////////////////////
//Delegates
//////////////////////////////////////
func itemsDownloaded(items: NSArray) {
print("Items downloaded")
for item in items
{
if let s = item as? Store
{
print(s.Address)
Globals.unsortedStoresList += [s]
//Map.addAnnotation(s.Annotation)
}
}
}
如有任何帮助,我们将不胜感激,提前致谢。
最佳答案
我找到了问题的临时解决方案 我将 StoreViewController.swift 修改为这个,如果有人遇到类似的问题。
class StoreViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate, StoresModelProtocoal {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
drawForm()
setUpMap()
self.hideKeyboardWhenTappedAround()
getCurrentLocation()
let hideStoreDetail: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.hideStoreDetails))
Map.addGestureRecognizer(hideStoreDetail)
//Create a nib for the custom cell and use it in the table
let nib = UINib(nibName: "CustomStoreCell", bundle: nil)
StoresListTable.registerNib(nib, forCellReuseIdentifier: "customStoreCell")
Globals.unsortedStoresList.removeAll() //I added this line of code to remove the old list
let storesModel = StoresModel()
storesModel.delegate = self
storesModel.downloadItems()
}
func itemsDownloaded(items: NSArray) {
print("Items downloaded")
for item in items
{
if let s = item as? Store
{
print(s.Address)
Globals.unsortedStoresList += [s]
Map.addAnnotation(s.Annotation)
}
}
do_table_refresh()
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return Globals.unsortedStoresList.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:CustomStoreCell = self.StoresListTable.dequeueReusableCellWithIdentifier("customStoreCell") as! CustomStoreCell
let s = Globals.unsortedStoresList[indexPath.row]
cell.loadItem(s.Name, StoreAddress: s.Address, StoreHoursOfOperation: s.HoursOfOperation, StoreDistanceFromCurrentLocation: String(s.DistanceFromCurrentLocation))
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//tableView.deselectRowAtIndexPath(indexPath, animated: true)
let s = Globals.unsortedStoresList[indexPath.row]
print(s.Name)
print(s.Address)
print(s.HoursOfOperation)
print(s.DistanceFromCurrentLocation)
//print("You selected cell #\(indexPath.row)!")
}
func do_table_refresh()
{
dispatch_async(dispatch_get_main_queue(), {
self.StoresListTable.reloadData()
return
})
}
关于objective-c - 如何填充数组并同时查看其数据 - Swift - IOS9,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37960020/