我正在尝试使用其他JSON调用中的数据重新填充UITableView。
然而，我目前的设置似乎不起作用，虽然有很多相同的问题，我可以找到我已经尝试过的答案。
我将我的API数据保存在CoreData个实体对象中。我正在用我的CoreData实体填充我的UITableView。
在我目前的设置中，我有3种不同的API调用，它们具有不同的数据量，当然还有不同的值。我需要能够在这3个数据集之间切换，这就是我现在要完成的任务。 （到目前为止没有进展）。
我有一个名为“loadSuggestions”的函数，这是我认为我的错误所在。
首先，我检查一下互联网连接。
我设置了managedObjectContext
我检查我需要调用哪个API（这是在调用函数之前确定的，我检查它是否按预期工作）
我从其尝试调用的实体中删除所有当前数据。 （我也尝试删除UITableView加载的最后一个数据中的数据。这没有改变任何东西。我也检查过这个有效。删除数据后，我检查它打印出一个空数组，我也尝试记录它删除的对象以确保。
然后我获取新数据，将其保存到临时变量中。然后将其保存到我的核心数据中。
然后我进行第二次API调用（取决于第一次调用的变量），获取数据并以相同的方式保存。
我将对象追加到数组UITableView填充它的单元格。 （我检查它也正确打印出来）
最后我重装了tableView。 （不改变一件事）
这是功能：
func loadSuggestions() {
println("----- Loading Data -----")
// Check for an internet connection.
if Reachability.isConnectedToNetwork() == false {
println("ERROR: -> No Internet Connection <-")
} else {
// Set the managedContext again.
managedContext = appDelegate.managedObjectContext!
// Check what API to get the data from
if Formula == 0 {
formulaEntity = "TrialFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/entry_weekly.json")
} else if Formula == 1 {
formulaEntity = "ProFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/entry_weekly.json")
} else if Formula == 2 {
formulaEntity = "PremiumFormulaStock"
formulaAPI = NSURL(string: "http://api.com/json/proff_weekly.json")
println("Setting Entity: \(formulaEntity)")
} else if Formula == 3 {
formulaEntity = "PlatinumFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/fund_weekly.json")
}
// Delete all the current objects in the dataset
let fetchRequest = NSFetchRequest(entityName: formulaEntity)
let a = managedContext.executeFetchRequest(fetchRequest, error: nil) as! [NSManagedObject]
for mo in a {
managedContext.deleteObject(mo)
}
// Removing them from the array
stocks.removeAll(keepCapacity: false)
// Saving the now empty context.
managedContext.save(nil)
// Set up a fetch request for the API data
let entity = NSEntityDescription.entityForName(formulaEntity, inManagedObjectContext:managedContext)
var request = NSURLRequest(URL: formulaAPI!)
var data = NSURLConnection.sendSynchronousRequest(request, returningResponse: nil, error: nil)
var formula = JSON(data: data!)
// Loop through the api data.
for (index: String, actionable: JSON) in formula["actionable"] {
// Save the data into temporary variables
stockName = actionable["name"].stringValue
ticker = actionable["ticker"].stringValue
action = actionable["action"].stringValue
suggestedPrice = actionable["suggested_price"].floatValue
weight = actionable["percentage_weight"].floatValue
// Set up CoreData for inserting a new object.
let stock = NSManagedObject(entity: entity!,insertIntoManagedObjectContext:managedContext)
// Save the temporary variables into coreData
stock.setValue(stockName, forKey: "name")
stock.setValue(ticker, forKey: "ticker")
stock.setValue(action, forKey: "action")
stock.setValue(suggestedPrice, forKey: "suggestedPrice")
stock.setValue(weight, forKey: "weight")
// Get ready for second API call.
var quoteAPI = NSURL(string: "http://dev.markitondemand.com/Api/v2/Quote/json?symbol=\(ticker)")
// Second API fetch.
var quoteRequest = NSURLRequest(URL: quoteAPI!)
var quoteData = NSURLConnection.sendSynchronousRequest(quoteRequest, returningResponse: nil, error: nil)
if quoteData != nil {
// Save the data from second API call to temporary variables
var quote = JSON(data: quoteData!)
betterStockName = quote["Name"].stringValue
lastPrice = quote["LastPrice"].floatValue
// The second API call doesn't always find something, so checking if it exists is important.
if betterStockName != "" {
stock.setValue(betterStockName, forKey: "name")
}
// This can simply be set, because it will be 0 if not found.
stock.setValue(lastPrice, forKey: "lastPrice")
} else {
println("ERROR ----------------- NO DATA for \(ticker) --------------")
}
// Error handling
var error: NSError?
if !managedContext.save(&error) {
println("Could not save \(error), \(error?.userInfo)")
}
// Append the object to the array. Which fills the UITableView
stocks.append(stock)
}
// Reload the tableview with the new data.
self.tableView.reloadData()
}
}
目前，当我推送到这个viewController时，这个函数在viewDidAppear中被调用，如下所示：
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(true)
tableView.allowsSelection = true
if isFirstTime {
loadSuggestions()
isFirstTime = false
}
}
它正确填充tableView，一切似乎按计划工作。
但是，如果我打开我的滑出菜单并调用函数来加载不同的数据，则没有任何反应，这是一个示例函数：
func platinumFormulaTapGesture() {
// Menu related actions
selectView(platinumFormulaView)
selectedMenuItem = 2
// Setting the data to load
Formula = 3
// Sets the viewController. (this will mostly be the same ViewController)
menuTabBarController.selectedIndex = 0
// Set the new title
navigationController?.navigationBar.topItem!.title = "PLATINUM FORMULA"
// And here I call the loadSuggestions function again. (this does run)
SuggestionsViewController().loadSuggestions()
}
这是2个相关的tableView函数：
行数：
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return stocks.count
}
和cellForRowAtIndexPath，（这是我使用CoreData设置单元格的地方）
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("com.mySuggestionsCell", forIndexPath: indexPath) as! mySuggestionsCell
let formulaStock = stocks[indexPath.row]
cell.stockNameLabel.text = formulaStock.valueForKey("name") as! String!
cell.tickerLabel.text = formulaStock.valueForKey("ticker") as! String!
action = formulaStock.valueForKey("action") as! String!
suggestedPrice = formulaStock.valueForKey("suggestedPrice") as! Float
let suggestedPriceString = "Suggested Price\n$\(suggestedPrice.roundTo(2))" as NSString
var suggestedAttributedString = NSMutableAttributedString(string: suggestedPriceString as String)
suggestedAttributedString.addAttributes(GrayLatoRegularAttribute, range: suggestedPriceString.rangeOfString("Suggested Price\n"))
suggestedAttributedString.addAttributes(BlueHalisRBoldAttribute, range: suggestedPriceString.rangeOfString("$\(suggestedPrice.roundTo(2))"))
cell.suggestedPriceLabel.attributedText = suggestedAttributedString
if action == "SELL" {
cell.suggestionContainer.backgroundColor = UIColor.formulaGreenColor()
}
if let lastPrice = formulaStock.valueForKey("lastPrice") as? Float {
var lastPriceString = "Last Price\n$\(lastPrice.roundTo(2))" as NSString
var lastAttributedString = NSMutableAttributedString(string: lastPriceString as String)
lastAttributedString.addAttributes(GrayLatoRegularAttribute, range: lastPriceString.rangeOfString("Last Price\n"))
percentDifference = ((lastPrice/suggestedPrice)*100.00)-100
if percentDifference > 0 && action == "BUY" {
lastAttributedString.addAttributes(RedHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference <= 0 && percentDifference > -100 && action == "BUY" {
lastAttributedString.addAttributes(GreenHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference <= 0 && percentDifference > -100 && action == "SELL" {
lastAttributedString.addAttributes(RedHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference == -100 {
lastPriceString = "Last Price\nN/A" as NSString
lastAttributedString = NSMutableAttributedString(string: lastPriceString as String)
lastAttributedString.addAttributes(GrayLatoRegularAttribute, range: lastPriceString.rangeOfString("Last Price\n"))
lastAttributedString.addAttributes(BlackHalisRBoldAttribute, range: lastPriceString.rangeOfString("N/A"))
}
cell.lastPriceLabel.attributedText = lastAttributedString
} else {
println("lastPrice nil")
}
weight = formulaStock.valueForKey("weight") as! Float
cell.circleChart.percentFill = weight
let circleChartString = "\(weight.roundTo(2))%\nWEIGHT" as NSString
var circleChartAttributedString = NSMutableAttributedString(string: circleChartString as String)
circleChartAttributedString.addAttributes(BlueMediumHalisRBoldAttribute, range: circleChartString.rangeOfString("\(weight.roundTo(2))%\n"))
circleChartAttributedString.addAttributes(BlackSmallHalisRBoldAttribute, range: circleChartString.rangeOfString("WEIGHT"))
cell.circleChartLabel.attributedText = circleChartAttributedString
cell.selectionStyle = UITableViewCellSelectionStyle.None
return cell
}
我将appDelegate定义为我班上的第一件事：
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
var managedContext = NSManagedObjectContext()
我认为这可能是导致错误的所有代码。我认为最可能的原因是loadSuggestions函数。
要强制更新tableView，我还尝试在setNeedsDisplay和setNeedsLayout上同时调用self.view和tableView，两者似乎都没有做任何事情。
任何有关此tableView拒绝更新的原因的建议都将是一个巨大的帮助！
我为代码的墙壁道歉，但我无法找到问题的确切来源。
答案 0 :(得分：2)
platinumFormulaTapGesture函数中的这一行不正确，
SuggestionsViewController().loadSuggestions()
这会创建一个新的SuggestionsViewController实例，它不是你在屏幕上拥有的实例。你需要得到一个指向你的指针。如何执行此操作取决于您的控制器层次结构，您尚未充分解释。